ES midterm 1

Chapter 16

Ch16Alternatives to Fossil Fuel Conservation Nuclear Renewables How will we convert to renewable energy? Fossil fuel supplies are limited and their use has consequences Nations have several options for future energy use Continue relying on fossil fuels until they are no longer available Increase funding to develop alternative energy sources dramatically Steer a middle course and gradually reduce our reliance on fossil fuels Our reliance on fossil fuels has consequences Transition should begin soon Technological and economic barriers prevent rapid switch Renewables receive little government help Need infrastructure for renewables Companies are unwilling to rapidly change Transitioning too slowly will cause disrupted economies and a degraded environment Conventional Alternatives Nuclear Hydroelectric Biomass Conventional alternatives Alternative energy sources currently the most developed and most widely used: nuclear energy, hydroelectric power, and energy from biomass These are all "conventional alternatives" to fossil fuels They exert less environmental impact These are best viewed as intermediates along a continuum of renewability Nuclear Power The U.S. generates the greatest amount of nuclear power 20% of U.S. electricity comes from nuclear sources France receives the highest proportion of its electricity from nuclear power (78%) Figure 15.18 Labeled Figure 15.19 Labeled Figure 15.21 Labeled Figure 15.22 Labeled Coal versus nuclear power Waste disposal remains a problem The long half-lives of radioisotopes = emitting radiation for thousands of years Radioactive waste must be placed in unusually stable and secure locations where radioactivity will not harm future generations Spent fuel rods must be stored Spent fuel rods are sunk in pools of cooling water to minimize radiation leakage By 2010, 75% of U.S. plants will have no room left for this type of storage They are now expanding their storage capacity through dry storage U.S. stores tons of waste U.S. power plants store 56,000 metric tons of high-level radioactive waste, as well as much more low-level radioactive waste Waste is held at 125 sites in over 39 states Over 161 million U.S. citizens live within 75 miles of temporarily stored waste Yucca Mountain waste repository First suggested in 1978 Under geological stable rock formation in Nevada Planned to receive waste for permanent storage Funding cancelled in 2011 by Federal government Currently no long term storage available or planned Storage of high-level radioactive waste Biomass Fuels Figure 16.4 Labeled Biomass fuels Biomass sources include a variety of materials Biopower = produced when biomass sources are burned in power plants, generating heat and electricity Biofuels = biomass sources converted into fuels to power automobiles Biofuels can power automobiles Ethanol = produces as a biofuel by fermentation Ethanol is widely added to U.S. gasoline to reduce emissions Any vehicle will run well on a 10% ethanol mix A primary biofuel Biofuels can power vehicles Biodiesel: a fuel produced from vegetable oil, used cooking grease, or animal fat This oil or fat is mixed with small amounts of ethanol or methanol in the presence of chemical catalyst Biodiesel's fuel economy is nearly as good, it costs just slightly more It is nontoxic and biodegradable Novel biofuels Cellulosic ethanol: ethanol produced from the cellulose in plant tissues by treating it with enzymes. Techniques for producing cellulosic ethanol are under development because of the desire to make ethanol from low-value crop waste (residue such as corn stalks and husks), rather than from the sugars of high-value crops Cars can run on ethanol Flexible fuel vehicles = run on 85% ethanol But, very few gas stations offer this fuel Researchers are refining techniques to produce ethanol from cellulose, so ethanol could be made from low-value crops, instead of high-value crops The Ethanol Dilemma Current production methods rely on food crops Correlated effects food production global hunger Biodiesel is produced from vegetable oil U.S. biodiesel producers use soybean oil Animal fats, used grease, and cooking oil can also be used Vehicles can run on 100% biodiesel, but the engine needs to be modified Biodiesel cuts down on emissions; its fuel economy is almost as good and costs slightly more than gasoline Alternative biofuel sources Hydroelectric Power Hydroelectric power The generation of electricity using kinetic energy of moving water Uses kinetic energy of moving water Harness energy by storing water in reservoirs behind dams Hydropower accounts for 2.2% of the world's energy supply And 16% of the world's electricity production A typical dam A run-of-river system Hydroelectric power is widely used Hydropower accounts for 2.2% of the world's energy supply And 16% of the world's electricity production Nations with large rivers and economic resources have used dams However, many countries have dammed their large rivers Hydropower uses three approaches Most hydroelectric power today comes from impounding water in reservoirs behind concrete dams that block the flow of river water and then letting the water pass through the dam. Because water is stored behind dams, this is called the storage technique The run-of-river technique: generates electricity without greatly disrupting a river's flow Method one: divert a portion of a river's flow through a pipe or channel, passing it through a powerhouse and returning it to the river Pumped Storage: to better control the timing of flow. Water is pumped from a lower reservoir to a higher reservoir at times when demand for power is weak and prices are low Hydropower is clean Two clear advantages over fossil fuels for producing electricity: It is renewable: as long as precipitation fills rivers we can use water to turn turbines It is clean: no carbon dioxide is emitted Hydropower is efficient It has an EROI of 10:1, as high as any modern-day energy source Hydropower's negative impacts Damming rivers destroys habitats Upstream areas are submerged Downstream areas are starved of water Natural flooding cycles are disrupted Thermal pollution of downstream water Periodic flushes of cold reservoir water can kill fish Dams block passage of fish fragmenting the river and reducing biodiversity Hydropower may not expand much more Most of the world's large rivers have already been dammed China's Three Gorges Dam is the world's largest dam; suboptimal site People have grown aware of the ecological impact of dams Developing nations will probably increase hydropower if they have rivers Bioenergy Bioenergy/ biomass energy: energy obtained from biomass Biomass: consists of organic material derived from living or recently organisms and it contains chemical energy that originated with sunlight and photosynthesis We harness bioenergy by burning biomass for heating, using biomass to generate electricity and processing biomass to create liquid fuels for transportation The New Renwables Solar Wind Geothermal Wave Power "New" renewable energy sources "New" renewables are a group of alternative energy sources that include Energy from the Sun, wind, geothermal heat, and movement of the ocean water They are commonly referred to as "new" because: They are not yet used on a wide scale Their technologies are still in a rapid phase of development They will play a much larger role in our energy use in the future New renewables provide little of our power The new renewables are growing fast Advantages of new renewables Benefits of the new renewables include: Alleviate air pollution and greenhouse gas emissions They are inexhaustible, unlike fossil fuels Diversify a country's energy economy Create jobs and are sources of income and taxes, especially in rural areas Green-collar jobs: jobs that design, install, maintain, and manage the development of technologies and rebuild and operate society's energy infrastructure New energy sources create jobs New technologies require more labor per unit of energy output More jobs will be generated than remaining with a fossil fuel economy Rapid growth will continue as: Population and consumption grow, energy demand increases, fossil fuel supplies decline, and people demand a cleaner environment Solar energy Energy from the sun Sun provides energy for almost all biological activity on Earth Each square meter of Earth receives about 1 kilowatt of solar energy = 17 times more than a lightbulb Active vs. Passive Solar Passive solar energy the most common way to harness solar energy Buildings are designed to maximize direct absorption of sunlight in winter and keep cool in summer Active solar energy collection uses technology to focus, move, or store solar energy Generally consists of dark, heat-absorbing metal plates mounted on rooftops in flat glass-covered boxes Passive solar heating is simple and effective Low south-facing windows maximize heat in the winter Overhangs on windows block light from above in the summer Thermal mass = construction materials that absorb, store, and release heat Planting vegetation in strategic locations By heating buildings in winter and cooling them in summer, passive solar methods conserve energy and reduce costs Active solar energy collection Flat plate solar collectors (solar panels) = one active method for harnessing solar energy Installed on rooftops Dark-colored, heat-absorbing metal plates Water, air, or antifreeze pass through the collectors, transferring heat throughout the building Heated water is stored and used later Figure 16.9 Labeled Concentrating Sunlight Focuses Energy We can harness energy from sunlight to produce electricity at concentrated solar power plants. Concentrated Solar Energy: a means of generating electricity at a large area (like a large centralized facilities) onto a smaller area (like homes or businesses). Several approaches are used. Method One: curved mirrors focus sunlight onto synthetic oil in pipes. The superheated oil is piped to a facility where it heats water, creating steam that drives turbines to generate electricity Method Two: hundreds of mirrors focus sunlight onto a central receiver atop a tall power tower. From there, air or fluids carry heat through pipes to steam-driven generator Solar energy use is increasing 1.5 million homes and businesses heat water with solar panels, mostly for swimming pools Solar panels are used far from any sort of electrical grid to help boil water and power rural hospitals Solar power need not be expensive or in regions that are always sunny Concentrating solar rays magnifies energy Solar cookers = simple, portable ovens that use reflectors to focus sunlight onto food Power tower = mirrors concentrate sunlight onto receivers to create electricity Solar-trough systems = mirrors focus sunlight on oil in troughs Superheated oil creates steam to produce electricity Photovoltaic cells generate electricity Photovoltaic cells = collect sunlight and convert it into electrical energy It converts sunlight to electrical energy when light strikes one of a pair of plates made primarily of silicon, a semiconductor that conducts electricity These are used with wind turbines and diesel engines Photovoltaic (photoelectric) effect = occurs when light strikes one of a pair of metal plates in a PV cell, causing the release of electrons, creating an electric current Thin-film solar photovoltaic materials compressed into ultra-thin sheets Less efficient as converting sunlight to electricity but cheaper to produce Net metering process by which homeowners or business with photovoltaic systems or wind turbines can see their excess solar energy or wind power to their local utility. Whereas feed-in-tariffs award producers with prices about the market rates, net metering offers market-rate prices A typical photovoltaic cell Solar power is little used but fast growing Solar energy was pushed to the sidelines as fossil fuels dominated our economy Funding for research and development erratic Because of a lack of investment, solar energy contributes only a miniscule amount of energy Solar energy is attractive in developing nations Hundreds of millions don't have electricity Some multinational companies are investing in solar energy Solar energy will continue to grow Solar energy use should increase As prices fall, technologies improve and governments enact economic incentives Japan and Germany lead the world in PV installation The U.S. may recover its leadership, given a 2005 federal tax credit and some state initiatives Solar power offers many benefits The Sun will burn for 4 - 5 billion more years Solar technologies are quiet, safe, use no fuels, contain no moving parts, and require little maintenance They allow local, decentralized control over power Solar power does not emit greenhouse gases and air pollution Developing nations can use solar cookers, instead of gathering firewood Net metering = PV owners can sell excess electricity to their local power utility Variable insolation is a drawback Not all regions are sunny enough to provide enough power, with current technology Daily and seasonal variation also poses problems Storage of energy becomes key Batteries, hydrogen, ...? Cost is a drawback Up-front costs are high Solar power remains the most expensive way to produce electricity The government has subsidized fossil fuels and nuclear energy at the expense of solar energy Wind has long been used for energy Wind Power: a source of renewable energy, in which kinetic energy from the passage of wind through wind turbines is used to generate electricity Wind turbines = devices that harness power from wind A mechanical assembly that converts the wind's kinetic energy, or energy of motion, into electrical energy Windmills have been used for 800 years to pump water The first windmill to generate electricity was built in the late 1800s After the 1973 oil embargo, governments funded research and development Today, wind power produces electricity for the same price as conventional sources Modern wind turbines Wind blowing into a turbine turns the blades of the rotor, which rotate machinery inside a compartment (nacelle) on top of a tall tower Wind farms Turbines erected in groups of up to hundreds of turbines Turbines harness wind as efficiently as possible Different turbines turn at different speeds Slight increases in wind velocity yield significant power output Wind is the fastest-growing energy sector Wind power grew 25% per year globally between 2000 and 2005 Five nations account for 80% of the world's wind power California and Texas produce the most wind power in the U.S. Wind power could be expanded to meet the electrical needs of the entire U.S. Offshore sites can be promising Costs to erect and maintain turbines in water are higher, but the stronger, less turbulent winds produce more power and make offshore wind more profitable Wind speeds are 20% greater over water than over land There is less air turbulence over water than land Currently, turbines are limited to shallow water Wind power has many benefits Wind produces no emissions once installed It prevents the release of CO2 It is more efficient than conventional power sources Turbines also use less water than conventional power plants Farmers and ranchers can lease their land Produces extra revenue Landowners can still use their land for other uses Advancing technology is also driving down the cost of wind farm construction Wind power downsides We have no control over when wind will occur Good wind sources are not always near population centers that need energy NIMBY Wind turbines pose a (very minor) threat to birds and bats Geothermal energy Geothermal energy: is thermal energy that arises from beneath Earth's surface Radioactive decay of elements under extremely high pressures deep inside the planet generates heat This heat rises through magma, fissures, and cracks Geothermal power plants use heated water and steam for direct heating and generating electricity The origins of geothermal energy Geothermal energy produces heat and electricity Most often wells are drilled hundreds or thousands of meters toward heated groundwater Water at temperatures of 150 - 370 degrees Celsius is brought to the surface and converted to steam, which turns turbines that generate electricity Hot groundwater can be used directly to heat buildings Cheap and efficient Geothermal energy is renewable in principle But if a geothermal plant uses heated water faster than groundwater is recharged, the plant will run out of water Operators have begun injecting municipal wastewater into the ground to replenish the supply Patterns of geothermal activity shift naturally An area that produces hot groundwater now may not always do so Geothermal energy is greatest in the west Heat pumps are highly efficient Geothermal ground source heat pumps (GSHPs) use thermal energy from near-surface sources of earth and water The pumps heat buildings in the winter by transferring heat from the ground into buildings In the summer, heat is transferred through underground pipes from the building into the ground Highly efficient, because heat is simply moved Currently installed on campus (JCC) Figure 16.22 Labeled Use of geothermal power is growing Currently, geothermal energy provides less than 0.5% of the total energy used worldwide It provides more power than solar and wind combined But, much less than hydropower and biomass Geothermal energy in the U.S. provides enough power to supply electricity to more than 4 million people The U.S., Japan, and China lead the world in geothermal power use Geothermal power has benefits and limits Benefits: Reduces emissions It does emit very small amounts of gases Limitations: May not be sustainable Water is laced with salts and minerals that corrode equipment and pollute the air Limited to areas where the energy can be trapped Restricted to areas where we can tap energy from naturally heated groundwater To help solve this problem -> Enhanced geothermal systems (EGS): a new approach whereby engineers drill deeply into rock, fracture it, pump in water, and then pump it out once it is heated below ground. This approach would enable us to obtain geothermal energy in many locations Tidal energy from the oceans Tidal energy: energy harnessed by erecting a dam across the outlet of a tidal basin. Water flowing with the incoming or outgoing tide through sluices in the dam turns turbines to generate electricity The rising and falling of ocean tides twice each day throughout the world moves large amounts of water Differences in height between low and high tides are especially great in long narrow bays These areas are best for harnessing tidal energy by erecting dams across the outlets of tidal basins Wave energy Wave energy: energy harnessed from the motion of ocean waves. Many designs for machinery to harness wave energy has been invented, but few have been adequately tested Can be developed at a greater variety of sites than tidal energy The motion of wind-driven waves at the ocean's surface is harnessed and converted from mechanical energy into electricity Many designs exist, but few are adequately tested Some designs are for offshore facilities and involve floating devices that move up and down the waves Wave energy is greater at deep ocean sites, but transmitting electricity to shore is very expensive Figure 16.23 Labeled Coastal onshore facilities Waves are directed into narrow channels and elevated reservoirs; electricity is generated when water flows out Another design uses rising and falling waves to push air in and out of chambers, turning turbines to generate electricity No commercial wave energy facilities are operating A third design uses the motion of ocean currents, such as the Gulf Stream Currently being tested in Europe Ocean thermal energy Ocean thermal energy conversion (OTEC) a potential energy sources that involves harnessing the solar radiation absorbed by tropical ocean water Each day, the tropical oceans absorb an amount of solar radiation equal to the heat content of 250 bbl The ocean's surface is warmer than deep water Ocean thermal energy conversion (OTEC) is based on this gradient in temperature Costs remain high and no facility is commercially operational What about hydrogen? Is a switch to H from C feasible? Hydrogen economy The development of fuel cells and hydrogen fuel shows promise to store energy in considerable quantities To produce clean, efficient electricity A hydrogen economy would provide a clean, safe, and efficient energy system By using the world's simplest and most abundant element as fuel Hydrogen economy Electricity generated from renewable sources could be used to produce hydrogen Vehicles, computers, cell phones, home heating, and countless other applications could be powered Basing an energy system on hydrogen could alleviate dependence on foreign fuels and help fight climate change A typical hydrogen fuel cell A hydrogen-fueled bus Production of hydrogen fuel Electrolysis = electricity is input to split hydrogen atoms from the oxygen atoms of water molecules: 2H2O 2H2 + O2 Produces pure hydrogen Will cause some pollution depending on the source of electricity, but less than than other processes Other ways of obtaining hydrogen Hydrogen can also be obtained from biomass and fossil fuels, such as methane (CH4) CH4 + 2H2O 4H2 + CO2 Results in emissions of carbon-based pollution Fuel cells produce electricity Once isolated, hydrogen gas can be used as a fuel to produce electricity within fuel cells The chemical reaction involved in that fuel cell is the reverse of electrolysis 2H2 + O2 2H2O The movement of the hydrogen's electrons from one electrode to the other creates electricity Hydrogen and fuel cells have many benefits We will never run out hydrogen is the most abundant element in the universe Can be clean and nontoxic to use May produce few greenhouse gases and other pollutants Can be no more dangerous than gasoline in tanks Cells are energy efficient Conclusions Fossil Fuels, Nuclear, New and Old Alternatives Conclusions Fossil fuels have helped us build our complex industrialized societies We are now approaching a turning point in history: fossil fuel production will begin to decline All energy comes from the sun... ...but not all sources are sustainable Peak oil and the increasing concern over global climate change have convinced many to shift to renewable energy homework Which of these is a major reason that we have used fossil fuels rather than their alternatives? Market costs are generally lower for fossil fuels than for their alternatives. Why is renewable energy use growing? There is increasing concern over the environmental impacts of fossil fuel combustion. How is the sun's energy production different from the process in which energy is produced in current nuclear power plants? The sun releases energy through nuclear fusion, whereas our current nuclear power technology releases energy through nuclear fission. Passive solar energy collection includes which of the following technologies? buildings designed and building materials chosen to maximize their direct absorption of sunlight Which of these statements is NOT true of wind power? Wind turbines take up large amounts of land that is then unsuitable for other purposes. What sort of threat does wind energy pose to certain kinds of wildlife? Flying creatures such as birds and bats are killed when they fly into wind turbine blades. The ultimate source of energy that drives wind power is __________. The sun A typical wind farm in the United States consists of __________. many very large wind turbines clustered in a region with a low human population The year 2030 goal set by the US Department of Energy is to generate __________. 20% of electricity using wind-powered systems Electricity in a wind turbine is generated __________. when spinning magnets move past a coil of copper wire Producing electricity using wind instead of fossil fuels__________. generates no carbon dioxide in the process What is the ultimate source for geothermal energy? the radioactive decay of elements deep within Earth Which of the following statements is NOT accurate regarding geothermal power? Geothermal power generators are one of the true fully sustainable energy sources. Ocean thermal energy conversion (OTEC) is NOT being used for energy generation anywhere right now. Why not? The cost of generating energy is much too high for OTEC to make economic sense. Why is there little to no growth expected for hydropower? Almost all rivers that can be dammed for power generation have been dammed already. What is the ultimate energy source for biomass (also known as biomass energy)? sunlight through the process of photosynthesis, in which the chemical potential energy of biomass originates Which of the following statements about ethanol is true? Growing corn for ethanol requires substantial inputs of fossil fuel energy. What is electrolysis? the splitting of water into component hydrogen and oxygen What two waste products are produced by hydrogen fuel cells? Water and heat

Chapter 18

The Urban Environment: Creating Sustainable Cities Case Study Urban growth boundary (UGB): a line on a map intended to separate areas desired to be urban from areas desired to remain rural Our Urbanizing World Urbanization: shift from the countryside into towns and cities Industrialization has driven urbanization Suburbs: smaller communities thing ring the cities Environmental factors influence the location of urban area Location Climate Topography Configuration of waterways People have moved to suburbs In developed nations Sprawl The spread of low-density urban or suburban development outward from an urban center Urban areas spread outward The physical spread of development at the rate that exceeds the rate of population growth Sprawl has several causes Human population growth (there are more of us alive each year) Per capita land consumption (each person is taking up more land than in the past What is wrong with sprawl? Transportation- forcing people to own a car, drive to places further Pollution - higher car use, motor oil, road salt all runoff and pollute waterways Health -physical inactivity Land use - less area for forests, fields, farmland, or ranchland Economics- drains tax dollars, money goes to infrastructure Creating Livable Cities Planning helps to create livable urban cities City planning: the professional pursuit that attempts to design cities in such a way as to maximize their efficiency, functionality, and beauty. Also known as urban planning Regional planning: deals with the same issues as city planners, but they work on broader geographic scales and coordinate their work their work with multiple municipal governments Zoning is a key tool for planning Zoning: the practice of classifying area for different types of development and land use Urban Growth boundaries are now widely used: Urban Growth Boundaries (UGBs): aim to revitalize downtown, protect working farms, orchard, ranches, and forests, and ensure urban dwellers access to open space "Smart Growth" and "new urbanism" aim to counter sprawl smart growth: a city planning concept in which a community's growth is managed in ways intended to limit sprawl and maintain or improve resident's quality of life New urbanism: seeks to design walkable neighborhoods with homes, businesses, schools and other amenities all close together for convenience Transit options help cities Mass transit: public systems of buses, trains, subways, or light rails that move large numbers of people at once while easing traffic congestion, taking up less space, and emitting less pollution Urban residents need parklands Green building bring benefits Green building: structures that are built from sustainable materials. Limit their use of energy and water, minimize health impacts on their occupants, control pollution, and recycle waste Leadership in Energy and Environmental Design (LEED): the leading set of standards for sustainable building. Urban Sustainability Urban centers bring a mix of environmental effects Resource use and efficiency Pollution Urban heat island effect: the phenomenon whereby a city becomes warmer than outlying areas because of the concentration of heat generating buildings, vehicles, and people, and because buildings and dark paved surfaces absorb heat and release it at night Land preservation Innovation Urban ecology helps cities toward sustainability Urban ecology: a scientific field of study that views cities explicitly as ecosystems. Researchers in this field apply the fundamentals of ecosystem ecology and systems science to urban areas Follow an ecosystem-centered model by striving for: 1. max efficient use of resources 2. recycle as much as possible 3. develop environmentally friendly tech 4. account full for external costs 5. use tax incentives to encourage sustainable practices 6. use locally produced resources 7. apply organic waste and wastewater to restore soil fertility 8. encourage urban agriculture

Chapter 17

Waste and Waste Management Types of waste Approaches to waste Hazardous waste Lecture Goals Types of waste Approaches to managing waste Conventional waste disposal methods Ways to reduce waste Industrial solid waste management Issues in managing hazardous waste Waste Waste = any unwanted material or substance that results from human activity or process Municipal solid waste (MSW)= non-liquid waste that comes from homes, institutions, and small businesses Industrial solid waste = waste from production of consumer goods, mining, agriculture, and petroleum extraction and refining Waste Waste (cont.) Hazardous waste =solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive Wastewater = water used in a household, business, or industry, as well as polluted runoff from our streets and storm drains Waste management Ranking three pathways of waste management: Minimizing the amount of waste we generate (source reduction) Recovering waste materials and finding ways to recycle them Disposing of waste safely and effectively Waste management Waste stream = flow of waste as it moves from its sources toward disposal destinations More efficient use of materials, consume less, buy goods with less packaging, reusing goods Source reduction: minimizing waste at its source Recovery (recycling, composting) = reclaiming materials with some value Recycling = sends used goods to manufacture new goods Composting = recovery of organic waste Municipal Solid Waste in the US Municipal solid waste (MSW) In the U.S., paper, yard debris, food scraps, and plastics are the principal components of municipal solid waste Even after recycling, paper is the largest component of solid waste Most waste comes from packaging In developing countries, food scraps are the primary contributor Waste generation in the US Waste generation in the US Waste generation in the U.S. In the U.S. since 1960, waste generation has increased 2.8 times What's in there? Check and see... Waste generation in developing nations Consumption increasing in developing nations Rising material standard of living More packaging Scavenger Economy Locally wealthy consumers often discard items that can still be used Landfill disposal methods Historically, open dumping and burning ...and still occurs throughout the world Most industrialized nations now use landfills or incineration facilities Sanitary landfills Sanitary landfills = waste buried in the ground or piled in large, engineered mounds Must meet national standards set by the EPA under the Resource Conservation and Recovery Act (RCRA) of 1976 Waste is partially decomposed by bacteria and compresses under its own weight to make more space Layered with soil to reduce odor, speed decomposition, reduce infestation by pets When a landfill is closed, it must be capped and maintained Landfills can produce gas for energy Bacteria can decompose waste in an oxygen-deficient environment Landfill gas = a mix of gases that consists of roughly half methane Can be collected, processed, and used like natural gas When not used commercially, landfill gas is burned off in flares to reduce odors and greenhouse emissions Landfills after closure? 8000 in US in 1988 Today < 1,700 Fewer larger landfills Thousands abandoned Closed landfills often converted into public parks Landfills have drawbacks Leachate liquid that results when substances from the trash dissolve in water as rainwater percolates downward. They can eventually escape The liner will become punctured Leachate collection systems eventually aren't maintained It is hard to find places suitable for landfills The Not-In-My-Backyard (NIMBY) syndrome The "Garbage barge" case In 1987, Islip, New York's landfills were full, and a barge traveled to empty the waste in North Carolina, which rejected the load It returned to Queens to incinerate the waste, after a 9,700 km (6,000 mile) global journey Incineration Incineration = a controlled process in which mixed garbage is burned at very high temperatures Incineration in specially constructed facilities Remaining ash must be disposed of in a hazardous waste landfill Hazardous chemicals are created and released during burning Scrubbers = chemically treat the gases produced in combustion to remove hazardous components and neutralize acidic gases Many incinerators are WTE Waste-to-energy facilities (WTE) = use the heat produced by waste combustion to create electricity Companies contract with communities to guarantee a minimum amount of garbage Long-term commitments interfere with the communities' later efforts to reduce waste Bridgeport RESCO 11th largest in US Reducing waste = better Source reduction = preventing waste generation in the first place Avoids costs of disposal and recycling Helps conserve resources Minimizes pollution Can save consumers and businesses money Much of the waste consists of materials used to package goods Waste reduction: manufacturers Can be reduced during manufacturing if consumers: Choose minimally packaged goods Buy unwrapped fruits and vegetables Buy in bulk Manufacturers can also: Use packaging that is more recyclable Reduce the size or weight of goods Apple Computer Legislating against waste Plastic grocery bags Grocery bags can take centuries to decompose Choke and entangle wildlife Litters the landscape Many governments, federal state and local, have banned non-biodegradable bags Westport was first in Connecticut Reuse as a strategy? Donate used items to resale centers Other actions include: Bring your own cup to coffee shops Buy rechargeable batteries Compost kitchen and yard wastes Rent or borrow instead of buying Home composting Food and yard waste into composting piles, underground pits, or specially constructed containers Heat from microbial action builds in the interior and decomposition proceeds Decomposers (earthworms, bacteria, soil mites, sow bugs, and other organisms) convert waste into high-quality compost Municipal composting Divert food and yard waste from the waste stream to composting facilities Reduces landfill waste Encourages soil biodiversity Reduces the need for chemical fertilizers Makes healthier plants and more pleasing gardens Recycling consists of three steps Recycling = collecting materials that can be broken down and reprocessed to manufacture new items Recycling diverts 58 million tons of materials away from incinerators and landfills each year Step 1 in the recycling loop is collection and processing of recyclable materials through curbside recycling or designated locations Materials recovery facilities (MRFs) = workers and machines sort items, then clean, shred and prepare them for reprocessing The second and third steps of recycling Step 2 is using recyclables to produce new products Many products use recycled materials In step 3, consumers purchase goods made from recycled materials Must occur if recycling is to function As markets expand, prices will fall Recycling has grown rapidly EPA: recycling is "one of the best environmental success stories of the late 20th century" Recycling rates vary widely, depending on the product 67% of major appliances are recycled Only 6% of plastics are recycled Growth in recycling from: A desire in municipalities to reduce waste output The public's desire to expand recycling New technologies and markets make recycling more and more cost effective Recycling rates vary widely Recycling is often not financially profitable because it is expensive to collect, sort and process recycled materials And, the more material that is recycled, the lower the price However, market forces do not take into account the health and environmental effects of not recycling Enormous energy and material savings through recycling Financial incentives Pay-as-you-throw The less waste a house generates the less it is charged for trash collection Bottle bills Challenges include including new kinds of containers and adjusting refunds for inflation Industrial solid waste U.S. industrial facilities generate 7.6 billion tons of waste 97% is wastewater State or local governments regulate industrial solid waste (with federal guidance) Regulation and economics Most methods and strategies of waste disposal, reduction, and recycling are similar to municipal solid waste Regulation varies from state to state In most cases, state and local regulations are less strict than federal rules In many areas, industries are not required to have permits, install landfill liners or leachate collection systems, or monitor groundwater for contamination Physical vs economic efficiency Physical efficiency: the amount of waste generated by a manufacturing process the less waste produced per unit or volume of product, the more efficient it is from a physical standpoint Physical efficiency is not equal to economic efficiency It can be cheaper to generate waste than to avoid waste Rising cost of waste disposal can align these Industrial ecology Industrial ecology = redesigning industrial systems to reduce resource inputs and to minimize physical inefficiency while maximizing economic efficiency Industrial systems should function like ecological systems, with little waste Industrial ecology Life cycle analysis = examine the life cycle of a product and look for ways to make the process more ecologically efficient Waste products can be used as raw materials Eliminating environmentally harmful products and materials Look for ways to create products that are more durable, recyclable, or reusable Beer ecology The Swiss Zero Emissions Research and Initiatives (ZERI) Foundation sponsors innovative projects that create goods and services without generating waste Hazardous waste Ignitable = substances that easily catch fire (natural gas, alcohol) Corrosive = substances that corrode metals in storage tanks or equipment Reactive = substances that are chemically unstable and readily react with other compounds, often explosively or by producing noxious fumes Toxic = substances that harm human health when they are inhaled, are ingested, or contact human skin Major Sources of Hazardous waste Industry produces huge amounts of hazardous waste Waste generation and disposal is highly regulated Mining Households Paints, batteries, oils, solvents, cleaners, pesticides Others Small businesses Agriculture Organic compounds Particularly hazardous because their toxicity persists over time Synthetic organic compounds = resist decomposition Keep buildings from decaying, kill pests, and keep stored goods intact Their resistance to decay causes them to be persistent pollutants They are toxic because they are readily absorbed through the skin They can act as mutagens, carcinogens, teratogens, and endocrine disruptors POPs: Persistent Organic Pollutants Persistant synthetic chemicals, can bioaccumulate, and are environmental and human toxicants Evidence of long-range transport of these substances to regions where they have never been used or produced Consequent threats they pose to the environment of the whole globe International calls for global actions to reduce and eliminate releases Heavy metals Lead, chromium, mercury, arsenic, cadmium, tin, and copper Used widely in industry for wiring, electronics, metal plating, pigments, and dyes They enter the environment when they are disposed of improperly Heavy metals that are fat soluble and break down slowly can bioaccumulate and biomagnify "E-waste" Electronic waste ("e-waste") = waste involving electronic devices Computers, printers, VCRs, fax machines, cell phones, iPods, Kindle, etc... Frequently disposed of in landfills should be treated as hazardous waste metals and synthetic organic compounds Disposal of hazardous waste For many years, hazardous waste was discarded without special treatment Public did not know it was harmful Assumed substances disappear or be diluted In 1980s, cities designate sites or special collection days household hazardous waste only! Disposal of hazardous waste Federal Resource Conservation and Recovery Act (RCRA) states are required to manage hazardous waste Large generators of hazardous waste must obtain permits and must be tracked "from cradle to grave" Intended to prevent illegal dumping Dumping of hazardous waste Since hazardous waste disposal is costly, it results in illegal and anonymous dumping by companies, Creating health risks Industrial nations illegally dump in developing nations Basel Convention, an international treaty, should prevent dumping but it still happens High costs of disposal encourages companies to invest in reducing their hazardous waste Three disposal methods for hazardous wastelandfills, surface impoundments, and injection wells These methods do nothing to lessen the hazards of the substances But they help keep the substance isolated from people, wildlife, and ecosystems Landfills Several impervious liners and leachate removal systems Design and construction standards are stricter than for ordinary sanitary landfills Must be located far from aquifers Surface impoundments Liquid hazardous waste or waste in dissolved form may be stored in one of these. It's shallow depressions are lined with plastic and clay Water containing waste evaporates, the residue of solid hazardous waste is then transported elsewhere The underlying clay layer can crack and leak waste, and rainstorms cause overflow, contaminating nearby areas Deep-well injection A long-term disposal method The well is intended to be isolated from groundwater and human contact However, the wells become corroded and leak waste into soil Radioactive waste Yucca Mountain in Nevada is now designated as the single-site repository for all U.S. nuclear waste The Waste Isolation Pilot Plant (WIPP) is the world's first underground repository for transuranic waste from nuclear weapons development Caverns holding the waste are 655 m (2,150 ft) below ground in a huge salt formation thought to be geologically stable WIPP became operational in 1999 and is receiving thousands of shipments of waste Contaminated sites Comprehensive Environmental Response Compensation and Liability Act (CERCLA) (1980) Superfund Established a federal program to clean up U.S. sites polluted with hazardous waste Experts identify polluted sites, take action to protect groundwater near these sites, and clean up the pollution Superfund Two events spurred creation of Superfund legislation In Love Canal, Niagara Falls, New York, buried toxic chemicals rose to the surface, contaminating homes and an elementary school In Times Beach, Missouri, contaminated with dioxin from waste oil sprayed on roads Later laws charged EPA with brownfields lands whose reuse or development are complicated by the presence of hazardous materials The Superfund process Once a Superfund site is identified, EPA scientists evaluate: How close the site is to human habitation Whether wastes are currently confined or likely to spread Whether the site threatens drinking water supplies Superfund Harmful sites are: Placed on the EPA's National Priority List Ranked according to the level of risk to human health that they pose Cleaned up on a site-by-site basis as funds are available The EPA is required to hold public hearings and inform area residents of tits findings and to receive feedback Who pays for cleanup? An average cleanup costs $25 million and takes 12 - 15 years Polluter pays principle = polluting parties were to be charged for cleanup Responsible parties often can't be found A trust fund was established by a federal tax on petroleum and chemical industries The fund is bankrupt, and neither the Bush administration nor Congress has moved to restore it, so taxpayers now pay all costs of cleanup Conclusion Our societies have made great strides in addressing our waste problems Modern methods of waste management are far safer for people and gentler on the environment Recycling and composting are growing rapidly Our prodigious consumption had created more waste than ever before Finding ways to reduce, reuse and efficiently recycle the materials and goods that we use stands as a key challenge for the new century

Chapter 12

Water Resources Saltwater Freshwater Human uses Freshwater systems Ocean water currents Currents: Driven by wind, heating/cooling, gravity, density differences, and the Coriolis effect Oceans are complex Oceans touch and are touched by every system They receive all inputs, sediment, pollutants, organisms Surface water is warmer than subsurface water Warmed by the sun and is less dense Deeper water is dense and sluggish Unaffected by winds, storms, sunlight, and temperature Ocean water also flows vertically Upwelling: the rising of cold, deep water to the surface Rich in nutrients High primary productivity and lucrative fisheries Downwelling: the sinking of warm, oxygen-rich water Provides oxygen for deep-water life Kelp forests Provide shelter and food for organisms Absorb wave energy and protect shorelines from erosion Rocky shore intertidal Coral reefs Coral reef mass of calcium carbonate mineral skeletons of millions of tiny, invertebrate corals Corals: Related to jellyfish w/tentacles to catch food Derive nourishment from symbiotic algae, zooxanthallae Mangrove forests in the tropics Mangroves: salt-tolerant trees with unique roots Habitat for fish, shellfish, birds Protect coastlines from storms Filter pollutants, stabilize soils, protect coral reefs Produce food, medicine, tools, wood Salt marshes Salt marshes: along coasts at temperate latitude Have salt-tolerant plants Filter pollution and stabilize shorelines Estuaries Estuaries: water bodies where rivers flow into the ocean Mixing fresh water with salt water Shallow water nurtures plants that provide critical habitat for shorebirds and shellfish Ocean fisheries Fisheries Modern fishing fleets deplete marine life rapidly Overfishing is the biggest threat We are now getting smaller fish because the tope of the food chain were the most desire and have been depleted Techniques driftnetting, longlining and bottom-trawling Bycatch the accidental capture of non-target animals, accounts for the deaths of millions of animals each year Freshwater Resources Ground water Surface water Lakes Water is unequally distributed Groundwater plays a key role Groundwater: water beneath the surface held in pores in soil or rock 20% of the Earth's supply of fresh water Aquifers: porous, spongelike formations of rock, sand, or gravel that hold water Zone of aeration: pore spaces are partly filled with water Zone of saturation: spaces are filled with water Water table: boundary between the two zones A typical aquifer The Ogallala Aquifer The world's largest known aquifer It underlies the Great Plains of the U.S. Unsustainable withdrawals are threatening the aquifer Surface waters: rivers and streams Surface water: on Earth's surface 1% of freshwater Becomes groundwater by infiltration Runoff: water that flows over land Water merges in rivers and ends up in a lake or ocean Watershed: the area of land drained by a river and its tributaries A river may shift course over time Floodplain: areas nearest to the river's course that are flooded periodically Soils are fertile due to frequent deposition of silt Good areas for agriculture A typical lake Ponds and lakes change over time Oligotrophic lakes and ponds: have low-nutrient and high-oxygen conditions They can transform into ... Eutrophic lakes and ponds: have high-nutrient and low-oxygen conditions Eventually, water bodies fill in completely through the process of aquatic succession Eutrophication can also result from human-caused nutrient pollution Human uses for water resources Water usage 70% of our water use is for agriculture Crop irrigation, watering of livestock 20% goes to industry, 10% for residential use Consumptive use: water is removed from an aquifer or surface water body and is not returned (e.g., irrigation) Nonconsumptive use: does not remove, or only temporarily removes, water Electricity generation at hydroelectric dams Figure 12.3 Labeled A typical dam The Aral Sea Agricultural demand "Flood and furrow" irrigation plants use only 40% of the water applied More efficient water use methods? Low-pressure spray irrigation sprays water downward Drip irrigation systems target individual plants Match crops to land and climate Don't grow cotton, rice, or alfalfa in arid areas Use selective breeding and genetic modification to produce crops that require less water Household Demand We can reduce water use by installing low-flow faucets, showerheads, and washing machines, and toilets High-efficiency Xeriscaping: a type of landscaping that uses plants adapted to arid conditions Industry and Municipalities Manufacturers are shifting to processes that use less water = less money Finding leaking pipes Indicators of water quality Chemical indicators pH, nutrient concentrations, dissolved oxygen concentration Physical indicators temperature, turbidity (density of suspended particles in water) Biological indicators presence of harmful microorganisms, species diversity of macroinvertebrates Pollution The release into the environment of matter or energy that causes undesirable impacts on the health or well-being of people or other organisms Water pollution comes in many forms and can cause diverse impacts on aquatic ecosystems and human health Point sources discrete locations such as factories, sewer pipes, and oil tankers. Non-point sources pollution that is cumulative, arising from multiple inputs over larger areas, such as farms, cities, and neighborhoods Water pollution takes many forms Toxic chemicals our waterways and coastal ecosystems have become polluted with toxic organic substances like pesticides, petroleum products, and other synthetic chemicals Pathogens and waterborne disease disease causing organisms (pathogenic viruses, protist, and bacteria) can enter drinking water supplies that become contaminated with human waste from inadequately treated sewage or animal waste from feedlots, chicken farms, or hog farms Nutrient pollution causes eutrophication and hypoxia (low dissolve oxygen concentrations) in surface waters When excess nitrogen and or phosphorous enters a water body, it fertilizes algae and aquatic plants, boosting their growth. As algae dies off, bacteria in sediments consume them. Because this decomposition requires oxygen , dissolved sxygen levels decline. These levels can drop too low to support fish and shellfish, leading to dramatic changes in aquatic ecosystems Dead zone Harmful algal blooms excessive nutrient concentrations sometimes gives rise to population explosions among several species of marine algae that produce powerful toxins Red tides toxic algal species that produce a red pigment that discolors the water Water pollution takes many forms (cont.) Biodegradable waste Wastewater water affected by human activities and is a source of biodegradable wastes Sediment High sediment concentrations impair aquatic ecosystems by interfering with the respiration of fish and invertebrates and smothering benthic organisms Oil pollution Net and plastic debris Thermal pollution (heating and cooling) Freshwater pollution sources Nutrient pollution Nutrient pollution from fertilizers, farms, sewage, lawns, golf courses leads to eutrophication and hypoxia Excess nitrogen and phosphorus in water boosts algal and aquatic plant growth Spreading algae cover the surface, decreasing sunlight Bacteria eat dead plants, reducing dissolved oxygen Fish and shellfish die Eutrophication is a natural process, but... Human activities dramatically increase the rate at which it occurs Federal legislative efforts The Federal Water Pollution Control Act (1972) Renamed the Clean Water Act in 1977 Made it illegal to discharge pollution without a permit Set standards for industrial wastewater Funded building of sewage treatment plants Marine reserves protect ecosystems Marine protected areas (MPAs) Marine reserves A typical wastewater treatment facility HOMEWORK Cause, Consequences, and Solutions Causes: Population growth Domestic water use for homes and landscaping Groundwater pumping for agriculture Consequences Water shortages Altered plant communities Salinization Solutions Improvement of wastewater treatment technology Development of water conservation policies Deployment of more efficient irrigation approaches

Chapter PP

Welcome to Environmental Science Course introduction and resources Brief lecture Discussion of sustainability Outline Course introduction and resources Activity: What are your issues? Brief lecture What is 'the environment'? Case study: Rapa Nui (Easter Island) Principles of sustainability Human impact Discussion: Are we on a sustainable path? Course Introduction Texts Course resources on Blackboard https://fairfield.blackboard.com/ Login using NetID and password Online homework on Mastering system http://www.masteringenvironmentalscience.com/ Register using CourseID and Access Code What are your issues? List what you view as the top three most important issues about the environment Be prepared to explain why these made the list, and others didn't... What is the 'environment'? Environment: consists of all of the living and nonliving things around us. Continents, oceans, clouds, and ice caps, animals, plants, etc. All surroundings with which we interact: Biotic: living things Animals, plants, forests, fungi, etc. Abiotic: Non-living things Continents, oceans, clouds, soil, rocks Buildings, human-created living centers Social relationships and institutions Perspectives on the environment Ecosystem services support life Humans are part of environment Our survival depends on a healthy, functioning planet. This is a fundamental insight of environmental science Humans exist within the environment and are part of nature Figure 1.2 Labeled The case of Rapa Nui Rapa Nui (Easter Island) The most isolated inhabited island on Earth Does this serve as a microscale model of global issues? Polynesians originally settled the island in first centuries AD "Discovered" on Easter Sunday, 1722 by Dutch explorers Moai were rock statues raised vertically without metal tools Principles of Sustainability A sustainable society does not use natural resources or produce wastes faster than they are regenerated or assimilated by the environment Principles of Sustainability 2. Society and the environment are interconnected, complex systems Principles of Sustainability 3. Sustainable societies make decisions based on equity and fairness Principles of Sustainability 4. Societies must have incentives and punishments to foster sustainable solutions The I=PAT Equation Human impact on the environment = population x affluence x technology We are increasing our burden on the planet Human population growth has accelerated we add over 200,000 people to the planet per day Consumption has risen even faster a better quality of life cf. dawn of civilization The rise in affluence has not been equal global inequality has doubled in past 40 years The Ecological Footprint The resources and environmental services used to produce your food, clothing, shelter, and other goods and services The cumulative area of biologically productive land and water required to provide the raw materials a person or population consumes and to dispose of or recycle the waste that is produced. Your Ecological Footprint? Drive a Car Burn 1 liter gas (8000 kcals) 2 kg carbon emissions ¼ kg of carbon monoxide Bicycle Burn 210 kcals Fewer emissions Are we on a sustainable path? "sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs." — UN Bruntdland Commission, 1987 Resource use and replenishment Industrial facilities Catch per unit effort (fisheries) Equitable and fair resource use? Can Science Help? What is science? yes What is environmental science? How is science used? What is science? Science focuses exclusively on the natural world, it does not deal with supernatural explanations. Science is a way of learning about what is in the natural world, how the natural world works, and how the natural world got to be the way it is. It is not simply a collection of facts, but is also a path to understanding. Scientists work in many different ways, but all science relies on testing ideas by figuring out what expectations are generated by an idea and making observations to find out whether those expectations hold true. What is science? (cont.) Accepted scientific ideas are reliable because they have been subjected to rigorous testing As new evidence is acquired and new perspectives emerge ideas can be revised. Science is a community endeavor. It relies on publication and peer review, which helps ensure that science moves in the direction of greater accuracy and understanding. This is facilitated by diversity within the scientific community, which offers a broad range of perspectives on scientific ideas. Millennium Ecosystem Assessment (2005) The most comprehensive scientific assessment of the condition of the world's ecological systems Major findings: Humans have drastically altered ecosystems; Changes have contributed to human well-being and economic development, but at a cost; Environmental degradation could get much worse; Degradation can be reversed, but it requires work. How is science used in society? Science ≠ Technology Science can inform or be distorted Union of Concerned Scientists timeline on scientific integrity and political interference in the federal government Pseudoscience (a.k.a. 'junk science') tries to masquerade as real science Pheromones and the Athena Institute

Chapter 7

The Production of Food Malthus' paradox Subsistence agriculture, the Green Revolution, and more sustainable methods Food Aid and food trade Human agriculture Human agriculture Thomas Malthus (1798) What did he get wrong? Changes in agricultural technology and science Decreases in fertility rates with demographic transition Logic was sound, but prediction was a couple centuries off... The race to feed the world Food production currently exceeds population growth But not everyone has enough to eat By 2050 we will have to feed 9 billion people Food security and undernutrition Food security Guarantee of an adequate, safe, nutritious, and reliable food supply Undernutrition: inadequate calories 870 million people suffer from undernutrition Every 5 seconds a child starves to death Overnutrition and malnutrition Overnutrition: too many calories each day In the United States 1.5 billion adults are overweight At least 500 million of those are obese Malnutrition: inadequate nutrients Diet lacks adequate proteins, essential lipids, vitamins, and minerals Malnutrition can lead to diseases Kwashiorkor Lack of protein or essential amino acids in the diet Children who stop breast-feeding are most at risk Bloated stomach, mental and physical disabilities Marasmus Due to protein deficiencyand insufficient calories Wasting of the body Deficiency in iodine and vitamin A are also prevalent Going old-school Sources of mortality in Developing Nations Crops and Animals: Major Patterns of Food Production Industrialized agriculture The Green Revolution Subsistence Agriculture Animal husbandry Prospects for increasing food production Human agriculture Relative effectiveness of Ag methods The Green Revolution1950s-1970s Transfer of new agricultural technology to developing nations Temporarily closed gap b/w production and need in some countries Production up 4%/yr vs. population growth at 2%/yr Heavy reliance on irrigation and fertilizers land +33% energy use +8000% The green revolution An intensification of the industrialization of agriculture in the developing world in the latter half of the 20th century that has dramatically increased crop yields produced per unit area of farmland. Practices include devoting large areas of to monocultures of crops specially bred for high yields and rapid growth; heavy use of fertilizers, pesticides, and irrigation water; and sowing and harvesting on the same piece of land more than once per year or per season. Norman Borlaug helped launch the Green Revolution. The high-yielding, disease-resistent wheat that he bred helped boost agriculture productivity in many developing countries Ag trends in the US Major patterns in agriculture: Last 60 years Resource intensive Increasing use of fertilizers Increasing use of chemical pesticides Increasing use of irrigation Energy (fossil fuel) intensive Machinery-intensive Refrigeration/preservation and transport Fewer types of crops/animals 90% of food from 15 plants and 8 animal species Industrial agriculture is a recent human invention Traditional agriculture the work of cultivating, harvesting, storing, and distributing crops was performed by human and animal muscle power, along with hand tools and simple machines Polycultures (many types) mixture of different crops in small plots of farmland, such as the Native American farming systems that mixed maize, beans, squash, and peppers. Industrial agriculture a form of agriculture that uses large-scale mechanization and fossil fuel combustion, enabling farmers to replace horses and oxen with faster and more powerful means of cultivating, harvesting, transporting, and processing crops. Other aspects include irrigation, and the use of inorganic fertilizers. Use of chemical herbicides and pesticides reduces competition from weeds and herbivory by insects. Monocultures planting vast areas with single crops in orderly, straight rows making farming more efficient, but they reduce biodiversity by eliminating habitats used by organisms in and around traditional farm fields 07_12.JPG Pesticides can impact non-target species Biological control pits one organism against another Biological control (biocontrol) control of pests and weeds with organisms that prey on or parasitize them, rather than with pesticides Integrated pest management incorporates numerous techniques, including close monitoring of pest populations, biocontrol approaches, use of synthetic chemicals when needed, habitat alternation, crop rotation, transgenic crops, alternative tillage methods, and mechanical pest removal Pollination the process by which male sex cells of a plant (pollen) fertilize female sex cells of a plant; it's the botanical version of sexual intercourse Unintended consequences of the GreenRevolution and industrialized agriculture National debt/interest payments in developing nations Loss of small/family farms Loss of traditional/alternative practices Farm debt Loss of culturally-specific crops Dependence on synthetic chemical fertilizers to replenish soil fertility Pesticide resistance in pest species (insects, weeds) Soil erosion Consequences Soil loss/ degradation (nutrient lose) Synthetic fertilizers and pesticides Energy use transportation and storage Irrigation (high use of water) Loss of indigenous knowledge and crops Animal husbandry (over population of domestic animals Solutions Crop rotation (soil loss, pesticides) Shelter belts (erosions and soil loss) Drip irrigation, contour farming (irrigation) Conservation tillage (fertilizers and soil loss) Irrigation boosts productivity but can damage soil Irrigation the artificial provision of water to support agriculture Waterlogging occurs when over-irrigation causes the water table to rise to the point that water drowns plant roots, depriving them of access to gases and essentially suffocating them Salinization the buildup of salts in surface soil layers Fertilizers boost crop yields but can be over applied Fertilizer a substance that promotes plant growth by supplying essential nutrients such as nitrogen or phosphorous Inorganic fertilizer are mined or synthetically manufactured nutrient supplements Organic fertilizer consists of the remains or wastes of organisms and include animal manure, crop residue, fresh vegetation (green manure) and compost ( a mixture produced when decomposers break down organic matter, including food and crop waste, in a controlled environment) The Dust Bowl United States, 1930s In late 1800 and early 1900, farmers and ranchers removed native grasses Dust Bowl 1930s drought, erosion = "black blizzards" of sand 1000s of farms abandoned Displaced persons relied on governmental help to survive The Grapes of Wrath by Steinbeck (1939) Soil is a resource Soil A complex system consisting of disintegrated rock, organic matter, water, gases, nutrients, microorganisms and other detritivores A renewable resource that can be depleted if abused Soil influences ecosystems as much as climate, latitude, and elevation Maintaining healthy soils Soil degradation Loss of soil quality and productivity Has caused 13% loss of grain production in last 50 years Erosion (causes soil degradation) Removal of material from one place to another by wind or water Deposition Arrival of eroded material at a new place Desertification a form of land degradation in which more than 10% of a land's productivity is lost due to erosion, soil compaction, forest removal, overgrazing, drought, salinization, climate change, water depletion, or other factors. Can result in the expansion of desert areas or creation of new ones. Soil erosion is a global problem Humans are the primary cause of erosion Human activities move over 10 times more soil than all other natural process Globally over 47 billion acres impacted by erosion/soil degradation United States loses 5 metric tons of soil for every ton of grain harvested Animal Husbandry Domesticated animals as sources of protein and other nutrients Raising animals only for food production Leads to a lot of consequences Global Consumption: Grain vs. Meat Livestock need land, grain, and water Overgrazing degrades agricultural land Greenhouse Gasses Animal Husbandry Benefits High quality protein Cheap products Unintended consequences Uses of 70% of grain crops in U.S. and therefore requires industrialized agriculture Feedlots/CAFOs (Mis)management of animal manure 3% of greenhouse gases Overgrazing degrades land Ethics? Ethics Do other organisms have rights to life? Do other organisms have rights to quality of life? Why don't we ask these same questions about plants? QUESTION: Weighing the Issues People in the U.S. can eat so much meat because of factory farming. However, many people are troubled by the conditions that animals are kept in. Should the quality of the animals' lives be considered when we decide how to raise food? Yes, the quality of an animal's life is important, too. Yes, but only if it does not interfere with access to meat. Yes, and people should have to pay more for their meat products. No, animals have no right to a quality of life. I don't care. I'm not particularly fond of cows or chickens. Overcoming Malthus Sustainable alternatives to Industrialized Agriculture Overcoming Malthus? Agriculture now dependent on soil water energy Global climate change will alter the first two, and is exacerbated by third Can we return to subsistence farming? Cheap Labor intensive Low technology Lower production per unit area Environmental degradation Use of marginal lands Clearing of new lands (tropical rain forests) Overcoming Malthus? Eat less Convert cash crops to food Eat lower on the food chain Pasture land to crop production Alternative foods More efficient use of captured E Increase crop yields? The 'new' revolution in crop yields 40% increase needed w/in 20 yrs Sustainable Soil, water, energy, environmental quality More equitable? Relies on the promise of biotechnology Higher yields Lower fertilizer/pesticide/water requirements Future Ag Biomass Pyramid? What's your global footprint? Go to www.footprintnetwork.org Calculate your 'global footprint' based on your lifestyle as before ... Now recalculate assuming a strict herbivore diet. Have we solved the problem? Yes or no, and why, by next class session... Sustainable agriculture Maintains the healthy soil, clean water, and genetic diversity essential to long-term crop and livestock production. It is agriculture that can be practiced in the same way far into the future while maintaining high yields One key component of making agriculture sustainable is reducing the fossil fuel we devote to agriculture and decreasing the pollution these inputs cause Farmer's markets Community- supported agriculture (CSA) consumers pay farmers in advance for a share of their yield, usually a weekly delivery of produce Soil A complex system consisting of disintegrated rock, organic matter, water, gases, nutrients, and microorganisms Parent material the base geologic material in a particular location (hardened lava, volcanic ash, rock or sediment deposited by glaciers, etc.) Bedrock the continuous mass of solid rock that makes up Earth's crust. Weathering parent material is broken down by this and it's the physical, chemical, and biological processes that converts large rock particles into smaller particles Horizon distinct layer of soil Soil profile the cross-section of a soil as a whole, from the surface to the bedrock Leaching the process by which solid materials such as minerals are dissolved in a liquid (usually water) and transported to another location Topsoil (A horizon) that portion of the soil that is most nutritive for plants and is thus of the most direct importance to ecosystems and to agriculture. TOP Organic (litter layer), topsoil, Eluviated (leaching layer), subsoil, weathered parent material, rock (parent material) BOTTOM Sustainable agriculture Crop rotation Growing different crops each year Returns nutrients to soil Prevents erosion, reduces pests Wheat or corn and soybeans Alternating the crops grown on a field from one season to the next is called Contour farming Plowing perpendicularly across a hill Furrows slow runoff and capture soil Tilling sideways across a hillside to slow water running down the slope Sustainable agriculture Terracing Level platforms cut into steep hillsides This "staircase" contains rain and irrigation water creates level platforms for crops on steep hillsides in order to hold rainwater and reduce soil erosion. Intercropping Planting crops in alternating bands Increases ground cover Decreases pests and disease Replenishes soil the practice of planting different crops in strategic arrangements within the same field.  Sustainable agriculture Shelterbelts (windbreaks) Rows of trees along edges Slows the wind are rows of trees or other tall plants grown at the edges of farm fields in order to slow down winds. Conservation tillage (no-till farming) Residues of previous crops left in field to prevent erosion Soil soaks up more water No-till farming Farming practices that minimize disturbance to soil are Conservation Reserve Program Established in the 1985 farm bill Pays farmers to stop cultivating highly erodible cropland and instead place it in conservation reserves planted with grasses and trees Food Production: Future trends Other sustainable trends include: Drip irrigation directly to root zone Breed new genetic varieties Recycle animal wastes Grain over animal production Source food locally Certified organic agriculture methods How Productive Is Organic Farming? Mäder's team found that soil in organic plots had Better structure Better supply of some nutrients Much more microbial activity Much more invertebrate biodiversity See pp. 156-7 Genetically Modified Organisms Promise Problems Policies Foods can be genetically modified Genetic engineering the process whereby scientists directly manipulate an organism's genetic material in the lab by adding, deleting, or changing segments of DNA Able to carry genes from one species to other through bacteria Genetically modified (GM) organisms organisms that have been genetically engineered using recombinant DNA Recombinant DNA DNA that has been patched together from the DNA of multiple organisms. The goal is to place genes that code for certain desirable traits into organisms lacking those traits. Transgenic an organism that contains DNA from another species Transgenes genes that have moved between them Biotechnology the material application of biological science to create products derived from organisms. Help develop medicines, clean up pollution, causes of cancer, etc GM crops around the world Transgenic Crops Not like traditional breeding methods Genetic engineering Recombinant DNA technology Incorporate desired genes into crops and animals from viruses, insects, fungi... Cloning of domestic animals Genetically modified organisms Genetic engineering: lab manipulation of DNA Add, delete, modify Genetically modified (GM) organisms: organisms genetically engineered using ... Recombinant DNA: DNA created from multiple organisms Genetically Modified Foods Stated objectives Disease resistance Drought tolerance Improved nutritional value Incorporate human vaccines Other unstated objectives (?) GURT Cross-marketing with ag chemicals GMOs: Environmental Problems Pest evolves resistance to genetically engineered toxin Escape of genes to other species "Super weeds" and/or "Super Pests" GM Food: Other Problems Access to new technologies profit driven (GURT, cross marketing) affordability in developing countries Consumer acceptance Labeling? Marketing? Food Distribution and Trade Patterns in food trade Food security Famine and Hunger Hotspots Civil Wars Drought Soil degradation Government corruption/incompetence Recent spike in hunger Global Trade in Grain Food Aid Food Aid: T or F? Alleviates chronic hunger Helps local agriculture Helps local economy Contributes to local ecological deterioration Postpones sustainable solutions False False False True True Lifeboat Ethics 'Lifeboat Ethics: The Case Against Helping the Poor' —Hardin (1974) http://www.garretthardinsociety.org/articles/art_living_on_a_lifeboat.html Too many people swamp a lifeboat... Lifeboat Ethics Lifeboat Ethics homework Causes, Consequences, and Solutions Causes Deforestation Poor farming practices Wind erosion Consequences Loss of topsoil Decreased soil fertility Lower water quality due to soil in runoff Solutions Planting of shelterbelts to block wind on farmland Contour planting No-till planting Traditional Relies on human and animal power Controls pests with natural pesticides and planting of multiple crops Many crops grown together on small plots of land industrial Relies on fossil fuel powered machinery Heavy use of synthetic fertilizer Single crops grown on large plots of land Controls pests with synthetic pesticides

Chapter 14

Ch. 14 Consequences of Global Climate Change Climate Models Impact Predictions IPCC AR4 WG II (say what?) Radiative Forcing (W per m2) 14_10b.jpg 14_10a.jpg Trends in Greenhouse Gases SE 14-16 Anthropogenic climate change What about the future? Prediction depends on: Understanding climate system Projecting human activity Coupled general circulation models (climate models) Computer simulations of climate trends Becoming more reliable in predicting climate change SE 14-16 Anthropogenic climate change SE 14-16 Anthropogenic climate change SE 14-16 Anthropogenic climate change SE 14-16 Anthropogenic climate change Current and future impacts Intergovernmental Panel on Climate Change (IPCC) An international panel of scientists and government officials established in 1988 Has presented a series of reports on the synthesis of scientific information concerning climate change Our dynamic climate Intergovernmental Panel on Climate Change (IPCC) provides evidence that: Climate is changing, we are the cause, and this change is already exerting impacts that will become increasingly severe Issues surrounding extent and consequences of global climate change are fastest-moving area of research Simplified Climate System Are humans responsible? Yes IPCC: >90% likely that most global warming due to humans Direct evidence from: direct measures of anthropogenic greenhouse gasses, isotope ratios of CO2, recent historical data, etc... Models that best fit data include human impacts Despite broad scientific consensus, outdated debate lingered into mid-2000s Skeptics funded by energy industry Use subsets of all data; present interpretations not common in scientific community Aimed to cast doubt on the scientific consensus Today, research focuses on extent of change Emissions Scenarios Predicted future patterns Effects on climate forcings Climate Models: Components Radiative forcing SRES Climate Scenarios IPCC Projections Impacts of Climate Change Facing uncertainty Predicting complexity Informing policy U.S. Global Change Research Program IPCC AR4 WG II Intergovernmental Panel on Climate Change Assessment Report 4 (2007) Working Group II Assess vulnerability of socio-economic and natural systems Predict negative, positive consequences Present options for adapting to it Changes in precipitation Precipitation change will vary by region Temperatures rise 0.2°C/10 yr Temperature change will vary by region Temperature changes are greatest in the Arctic Ice caps shrinking Storms are increasing Sea ice is thinning Worldwide, glaciers are melting rapidly Melting snow and ice Mountaintop glaciers are disappearing In Glacier National Park, only 27 of 150 glaciers remain Risks of sudden floods as ice dams burst Reducing summertime water supplies Melting of the Greenland ice sheet is accelerating As ice melts, darker, less-reflective surfaces are exposed and absorb more sunlight, causing more melting Rising sea levels Rising sea levels As glaciers and ice melt, increased water will flow into the oceans As oceans warm, they expand Outcome: IPCC predicts mean sea level to be 18-59 cm (7-23 in) higher than today's at the end of the 21st century Leads to beach erosion, coastal floods, and intrusion of salt water into aquifers Effects on organisms/ecosystems Global warming modifies temperature-dependent phenomena Timing of migration, breeding Shifts in geographic range of organisms Animals and plants will move towards the poles or upward in elevation 20-30% of all species will be threatened with extinction Plants act as carbon sinks; fewer plants means more CO2 in the atmosphere Climate changes cause extinction Societal impacts Agriculture: growing seasons shortened, crops more susceptible to droughts and failure; crop production will decrease, worsening hunger Forestry: increased insect and disease outbreaks, increased chance of forest fires (especially in rainforests) Health: heat waves and stress can cause death, respiratory ailments, expansion of tropical diseases, increased mortaliaty from storms hunger-related ailments Economic Impacts Costs will outweigh benefits Will cost 1-5% GDP on average globally Inequality in costs among developed, developing nations Climate change could cost 5-20% of GDP by 2200 Effects on Ecosystems, Human Health Regional Impacts Adaptation vs. Mitigation Adaptation, Mitigation Adaptation is essential to cope with the unavoidable Mitigation is essential to prevent the avoidable John Holdren's view "We basically have three choices - mitigation, adaptation, and suffering. We're going to do some of each. The question is what the mix is going to be. The more mitigation we do, the less adaptation will be required, and the less suffering there will be." IPCC Call to Immediate Action "Due to the inertia of both climate and socio-economic systems, the benefits of mitigation actions initiated now may result in significant avoided climate change only after several decades. This means that mitigation actions need to start in the short-term in order to have a medium-and longer-term benefits and to avoid lock-in of carbon-intensive technologies."

Chapter 1 extra PP

Energy and Nutrients in Ecosystems Energy flows through... Nutrients cycle within Physical laws are boundaries Set limits on the processes and behaviors of environmental systems Guide our understanding of structure of complex systems Provide insight into some important environmental issues Law of Conservation of Mass: The physical law stating that matter may be transformed from one type of substance into others, but that it cannot be created or destroyed. Matter cannot be created or destroyed but can be rearranged in form! Assumption: Closed system Exception: Mass defect in special relativity and quantum theory (E = mc2) Lavoisier's laboratory Laws of Thermodynamics First Law of Thermodynamics There is no change in the quantity of energy in any energy conversion Second Law of Thermodynamics In all conversion processes energy decreases in its ability to do work Entropy increases, often as 'waste' heat Third Law of Thermodynamics You can never escape! You can never break a law of physics Energy Conversion Efficiency: The practice of reducing energy use as a way of extending the lifetime of our fossil fuel supplies, of being less wasteful, and of reducing our impact on the environment. Conservation can result from behavioral decisions or from technologies that demonstrate energy efficiency. Ratio of work to total energy expended Critical to understanding energy storage and use (by humans as well as other organisms) A living power plant Light energy input from the Sun Photosynthesis: The process by which autotrophs produce their own food. Sunlight powers a series of chemical reactions that convert carbon dioxide and water into sugar (glucose), thus transforming low-quality energy from the sun into high-quality energy the organism can use. Process used by majority of autotrophs to capture energy from the environment Conversion of energy to stored organic compounds Conversion efficiency? Primary Production: The conversion of solar energy to the energy of chemical bonds in sugars during photosynthesis, performed by autotrophs. Compare secondary production. The amount of chemical energy fixed by autotrophs per area • time ex: g/m2•day Gross primary production vs. net primary production GPP = total energy fixed NPP = GPP - energy used for maintenance and respiration losses NPP is the amount of energy available to heterotrophs, and is therefore an important parameter in understanding living systems Net primary productivity NPP by biome Autotrophs vs. Heterotrophs Autotrophs- self feeding Obtain energy from inorganic sources photosynthesis chemosynthesis Input source of energy for living components of systems Heterotrophs Must consume organic material to obtain energy Herbivores (plants) Carnivores (animal) Omnivores (both) Detritivores (scavengers, eat dead or decaying material to get energy) A savannah ecosystem Energy flows Nutrient cycles Chemistry and Life The connection between matter and energy Atoms Compounds are made of atoms Macromolecules essential to life Proteins Build an organism Gets things done Carbohydrates Sugar; starch Energy storage molecules for living organisms Lipids Nucleic acids DNA (at right) RNA Instructions to get stuff done Food = chemical energy in bonds Key Biogeochemical Cycles Water, Carbon, Phosphorous & Nitrogen Water Carbon Phosphorous Nitrogen

Chapter 5

• Economics and the Environment Economy: A social system that converts resources into goods and services. Economics: The study of how we decide to use scarce resources to satisfy demand for goods and services. o Economies rely on goods and services from the environment o Economic theory moved from "invisible hand" to supply and demand Classical economics: Founded by Adam Smith, the study of the behavior of buyers and sellers in a capitalist market economy. Holds that individuals acting in their own self-interest may benefit society, provided that their behavior is constrained by the rule of law and by private property rights and operates within competitive markets. See also neoclassical economics. Neoclassical economies: A mainstream economic school of thought that explains market prices in terms of consumer preferences for units of particular commodities and that uses cost-benefit analysis. Compare ecological economics; environmental economics. Cost-benefit analysis: A method commonly used by neoclassical economists, in which estimated costs for a proposed action are totaled and then compared to the sum of benefits estimated to result from the action. o Neoclassical economics has environmental consequences Replacing resources External Costs • External cost: A cost borne by someone not involved in an economic transaction. Examples include harm to citizens from water pollution or air pollution discharged by nearby factories. o Health problems o Declines in resources o Aesthetic damage o Declining real estate values Discounting Growth • Economic growth: An increase in an economy's activity—that is, an increase in the production and consumption of goods and services. o How sustainable is economic growth? Environmental economies: A developing school of economics that modifies the principles of neoclassical economics to address environmental challenges. Most environmental economists believe that we can attain sustainability within our current economic systems. Compare ecological economics; neoclassical economics. Ecological economics: A developing school of economics that applies the principles of ecology and systems thinking to the description and analysis of economies. Compare environmental economics; neoclassical economics. Steady-state economies: An economy that does not grow or shrink but remains stable. o We can assign monetary value to ecosystem good and services Nonmarket value: A value that is not usually included in the price of a good or service. o We can measure progress with full cost accounting Gross Domestic Product (GDP): The total monetary value of final goods and services produced in a country each year. GDP sums all economic activity, whether good or bad. Compare Genuine Progress Indicator (GPI). Genuine Progress Indicator: An economic indicator that attempts to differentiate between desirable and undesirable economic activity. The GPI accounts for benefits such as volunteerism and for costs such as environmental degradation and social upheaval. Compare Gross Domestic Product (GDP). Full cost accounting/ true cost accounting: An accounting approach that attempts to summarize all costs and benefits by assigning monetary values to entities without market prices and then generally subtracting costs from benefits. Examples include the Genuine Progress Indicator, the Happy Planet Index, and others. Also called true cost accounting. o Markets Can Fail Market failure: The failure of markets to take into account the environment's positive effects on economies (for example, ecosystem services) or to reflect the negative effects of economic activity on the environment and thereby on people (external costs). • Environmental Policy: An Overview Policy: A rule or guideline that directs individual, organizational, or societal behavior. Public Policy: Policy made by governments, including those at the local, state, federal, and international levels; it consists of legislation, regulations, orders, incentives, and practices intended to advance societal welfare. See also environmental policy. Environmental policy: Public policy that pertains to human interactions with the environment. It generally aims to regulate resource use or reduce pollution to promote human welfare and/or protect natural systems. o Environmental policy addresses issues of fairness and resource use Why governments intervene: • To provide social services • To provide a safety net • To eliminate unfair advantages held by single buyers or sellers • To manage publicly held resources • To minimize pollution and other threats to health and quality of life ((end)) • Tragedy of the commons o Tragedy of the commons: The process by which publicly accessible resources open to unregulated use tend to become damaged and depleted through overuse. Coined by Garrett Hardin and widely applicable to resource issues. • Free riders o Free riders: A party that fails to invest in controlling pollution or carrying out other environmentally responsible activities and instead relies on the efforts of other parties to do so. For example, a factory that fails to control its emissions gets a "free ride" on the efforts of other factories that do make the sacrifices necessary to reduce emissions. • External cost o Various factors can obstruct environmental policy o Science informs policy but it sometimes disregarded • US Environmental Law and Policy o The federal government's three branches shape policy Legislation: Statutory law. Regulation: A specific rule issued by an administrative agency, based on the more broadly written statutory law passed by Congress and enacted by the president. o Early US environmental policy promoted development First Period: 1780s- late 1800s: General Land Ordinances of 1785 and 1787 Basically took land from Native Americans o The Second wave of US environmental policy encouraged conservation In the late 1800s Aimed to alleviate some of the environmental impacts of westward expansion o The third wave responded to pollution 20th century driven my technology o Passage of NERPA and creation of EPA were milestones National Environmental Policy Act (NERPA): A U.S. law enacted on January 1, 1970, that created an agency called the Council on Environmental Quality and required that an environmental impact statement be prepared for any major federal action. Environmental impact statement (EIS): A report of results from detailed studies that assess the potential effects on the environment that would likely result from development projects or other actions undertaken by the government. Environmental Protection Agency (EPA): An administrative agency charged with conducting and evaluating research, monitoring environmental quality, setting standards, enforcing those standards, assisting the states in meeting standards and goals for environmental protection, and educating the public. o Social context for policy evolves o Environmental policy advances today on the international stage • International Environmental Policy o Globalization makes international institutions vital Globalization: The process by which the world's societies have become more interconnected, linked by trade and communication technologies in countless ways. o International law includes customary law and conventional law Customary law: International law that arises from long-standing practices, or customs, held in common by most cultures. Compare conventional law. Conventional law: International law that arises from conventions, or treaties, that nations agree to enter into. Compare customary law. North American Free Trade Agreement (NAFTA): A 1994 treaty among Canada, Mexico, and the United States that reduced or eliminated barriers to trade (such as tariffs) among these nations. Side agreements were negotiated to minimize the degree to which protections for workers and the environment were undermined. o Several organizations shape international environment policy The United Nations • The United Nations: Organization founded in 1945 to promote international peace and to cooperate in solving international economic, social, cultural, and humanitarian problems. The World Bank • The World Bank: Institution founded in 1944 that serves as one of the globe's largest sources of funding for economic development, including such major projects as dams, irrigation infrastructure, and other undertakings. The World Trade Organization • The World Trade Organization: Organization based in Geneva, Switzerland, that represents multinational corporations and promotes free trade by reducing obstacles to international commerce and enforcing fairness among nations in trading practices. Nongovernmental organizations • Nongovernmental organizations: An organization not affiliated with any national government, and frequently international in scope, that pursues a particular mission or advocates for a particular cause. • Approaches to Environmental policy o Policy can follow three approaches Lawsuits of the court Command-and-control policy • Command-and-control policy: A top-down approach to policy, in which a legislative body or a regulating agency sets rules, standards, or limits and threatens punishment for violations of those limits. Economic policy tools o Green taxes discourage undesirable activities Green taxes: A levy on environmentally harmful activities and products aimed at providing a market-based incentive to correct for market failure. Compare subsidy. Polluter-pays principle: Principle specifying that the party responsible for producing pollution should pay the costs of cleaning up the pollution or mitigating its impacts. o Subsidies promote certain activities Subsidy: A government grant of money or resources to a private entity, intended to support and promote an industry or activity. o Eco labeling empowers consumers Ecolabeling: The practice of designating on a product's label how the product was grown, harvested, or manufactured, so that consumers are aware of the processes involved and can judge which brands use more sustainable processes. o Emissions trading can produce cost-effective results Emissions trading: The practice of buying and selling government-issued marketable emissions permits to conduct environmentally harmful activities. Under a cap-and-trade system, the government determines an acceptable level of pollution and then issues permits to pollute. A company receives credit for amounts it does not emit and can then sell this credit to other companies. Compare cap-and-trade. Cap-and-trade: An emissions trading system in which government determines an acceptable level of pollution and then issues polluting parties permits to pollute. A company receives credit for amounts it does not emit and can then sell this credit to other companies. o Market incentives are diverse at the local level • Sustainable Development Sustainable development: Development that satisfies our current needs without compromising the future availability of natural capital or our future quality of life. o Sustainable development involves environmental protection, economic well-being, and social equity o Sustainable development is global

Chapter 3

• Evolution: The Source of Earth's Biodiversity o Natural Selection Shapes Organisms Natural selection: The process by which traits that enhance survival and reproduction are passed on more frequently to future generations of organisms than traits that do not, thus altering the genetic makeup of populations through time. Natural selection acts on genetic variation and is a primary driver of evolution. Adaption: (1) The process by which traits that lead to increased reproductive success in a given environment evolve in a population through natural selection. (2) See adaptive trait. o Selection acts on genetic variation Convergent evolution: the evolutionary process by which very unrelated species acquire similar traits as they adapt to selective pressures from similar environments o Evidence of Selection is all around us Charles Darwin: English naturalist who proposed the concept of natural selection as a mechanism for evolutionand as a way to explain the great variety of living things. Compare Wallace, Alfred Russel. Alfred Russel Wallace: English naturalist who proposed, independently of Charles Darwin, the concept of natural selection as a mechanism for evolution and as a way to explain the great variety of living things. Artificial selection: Natural selection conducted under human direction. Examples include the selective breeding of crop plants, pets, and livestock. o Understanding Evolution is Vital for Modern Society o Evolution Generates Biodiversity Biological diversity/biodiversity: The variety of life across all levels of biological organization, including the diversity of species, their genes, their populations, and their communities. o Speciation Produces New Types of Organisms Speciation: The process by which new species are generated. o We can Infer the History of Life's diversification Phylogenetic trees: A treelike diagram that represents the history of divergence of species or other taxonomic groups of organisms. o Fossils Reveal Life's History Fossil: The remains, impression, or trace of an animal or plant of past geological ages that has been preserved in rock or sediments. Extinction: The disappearance of an entire species from Earth. Compare extirpation. o Some species are especially vulnerable to extinction o Earth has seen episodes of mass extinction Mass extinction events: The extinction of a large proportion of the world's species in a very short time period due to some extreme and rapid change or catastrophic event. Earth has seen five mass extinction events in the past half-billion years. o The sixth mass extinction is upon us • Ecology and the Organism Ecology: The science that deals with the distribution and abundance of organisms, the interactions among them, and the interactions between organisms and their abiotic environments. o We study ecology at several levels Biosphere: The sum total of all the planet's living organisms and the abiotic portions of the environment with which they interact. Ecologist: an expert in or student of ecology: Population ecology: The study of the quantitative dynamics of population change and the factors that affect the distribution and abundance of members of a population Community: In ecology, an assemblage of populations of organisms that live in the same place at the same time. Community ecology: The scientific study of patterns of species diversity and interactions among species, from one-to-one interactions to complex interrelationships involving entire communities Ecosystems: All organisms and nonliving entities that occur and interact in a particular area at the same time. Ecology: The science that deals with the distribution and abundance of organisms, the interactions among them, and the interactions between organisms and their abiotic environments. Landscape ecology: The study of how landscape structure affects the abundance, distribution, and interaction of organisms. This approach to the study of organisms and their environments at the landscape scale focuses on broad geographical areas that include multiple ecosystems. o Habitat, niche, and specialization are key concepts in ecology Habitat: The specific environment in which an organism lives, including both biotic and abiotic factors. Habitat use: The process by which organisms use habitats from among the range of options they encounter. Habitat selection: The process by which organisms select habitats from among the range of options they encounter. Niche: The functional role of a species in a community. Specialist: a person who concentrates primarily on a particular subject or activity; a person highly skilled in a specific and restricted field. Generalist: a person competent in several different fields or activities: • Population Ecology o Populations show features that help predict their dynamics Population size • Population size: The number of individual organisms present at a given time in a population. Population density • Population density: The number of individuals within a population per unit area. Compare population size Population distribution • Population distribution: The spatial arrangement of organisms within a particular area. Sex ratio • Sex ratio: The proportion of males to females in a population. Age structure • Age structure: o We can Measure Population Growth Demographer: A social science that applies the principles of population ecology to the study of statistical change in human populations. Population change is determined by four factors: • Natality: births within the population • Mortality: deaths within the population • Immigration: arrival of individuals from outside the population • Emigration: departure of individuals from the population • Rate of natural increase: The rate of change in a population's size per unit time (generally expressed in percent per year), taking into accounts births, deaths, immigration, and emigration. Compare rate of natural increase. • Population growth rate: The rate of change in a population's size per unit time (generally expressed in percent per year), taking into accounts births, deaths, immigration, and emigration. Compare rate of natural increase. o Unregulated populations increase by exponential growth Exponential growth: The increase of a population (or of anything) by a fixed percentage each year. o Limiting Factors Restrain Growth Limiting factors: A physical, chemical, or biological characteristic of the environment that restrains population growth. Carrying capacity: The maximum population size that a given environment can sustain. Logistic growth: A plot that shows how the initial exponential growth of a population is slowed and finally brought to a standstill by limiting factors. Density-dependent: The condition of a limiting factor whose effects on a population increase or decrease depending on the population density. Compare density-independent factor. Density-independent: The condition of a limiting factor whose effects on a population are constant regardless of population density. Compare density-dependent factor. o Carrying capacities can change • Conserving Biodiversity o Innovative solutions are working o Climate change poses an extra challenge Chapter 4: Species Interaction • Species Interactions o Competition Can Occur When Resources are limited Competition: relationship in which multiple organisms seek the same limited resource Resource partitioning: the process by which species adapt to competition by evolving to use slightly different resources, thus minimizing interference with one another o Predators Kill and Consume Prey Predation: The process in which one species (the predator) hunts, tracks, captures, and ultimately kills its prey. o Parasites Exploit Living Hosts Parasitism: A relationship in which one organism, the parasite, depends on another, the host, for nourishment or some other benefit while simultaneously doing the host harm. Compare mutualism. o Herbivores Exploit Plants Herbivory: the consumption of plants by animals. o Mutualists Help One Another Mutualism: A relationship in which all participating organisms benefit from their interaction. Compare parasitism. Symbiosis: a relationship between different species of organisms that live in close physical proximity. People often use the term "symbiosis" where referring to a mutualism, but symbiotic relationships can be either parasitic or mutualistic Pollination: A plant-animal interaction in which one organism (for example, a bee or a hummingbird) transfers pollen (containing male sex cells) from flower to flower, fertilizing ovaries (containing female sex cells) that grow into fruits with seeds. • Ecological Communities Community: In ecology, an assemblage of populations of organisms that live in the same place at the same time. o Energy passes among trophic level Trophic level: Rank in the feeding hierarchy of a food chain. Organisms at higher trophic levels consume those at lower trophic levels. • Producers (autotroph): an organism that uses energy from sunlight to produce its own food. Includes green plants, algae, and cyanobacteria • Consumers: • Detritivores and Decomposers: an organism such as a millipede or soil insect that scavenges the waste products or dead bodies of other community members...........organism, such as fungus or bacterium, that breaks down leaf litter and other nonliving matter into simple constituents that can be taken up and used by plants o Energy, Numbers, and Biomass Decrease at Higher Trophic Levels Biomass: (1) In ecology, organic material that makes up living organisms; the collective mass of living matter in a given place and time. (2) In energy, organic material derived from living or recently living organisms, containing chemical energy that originated with photosynthesis. o Food Webs Show Feeding Relationships and Energy Flow Food chain: A linear series of feeding relationships. As organisms feed on one another, energy is transferred from lower to higher trophic levels. Compare food web. Food web: A visual representation of feeding interactions within an ecological community that shows an array of relationships between organisms at different trophic levels. Compare food chain. o Some Organisms play Outsized Roles Keystone species: A species that has an especially far-reaching effect on a community. Trophic cascade: A series of changes in the population sizes of organisms at different trophic levels in a food chain, occurring when predators at high trophic levels indirectly promote populations of organisms at low trophic levels by keeping species at intermediate trophic levels in check. Trophic cascades may become apparent when a top predator is eliminated from a system. o Communities Respond to Disturbance in Various Ways Disturbances: An event that affects environmental conditions rapidly and drastically, resulting in changes to the community and ecosystem. Disturbance can be natural or can be caused by people Resistance: The ability of an ecological community to remain stable in the presence of a disturbance. Compare resilience. Resilience: The ability of an ecological community to change in response to disturbance but later return to its original state. Compare resistance. o Succession Follows Severe Disturbance Succession: A stereotypical series of changes in the composition and structure of an ecological community through time. See primary succession; secondary succession. Primary Succession: A stereotypical series of changes as an ecological community develops over time, beginning with a lifeless substrate. In terrestrial systems, primary succession begins when a bare expanse of rock, sand, or sediment becomes newly exposed to the atmosphere and pioneer species arrive. Compare secondary succession. Secondary succession: A stereotypical series of changes as an ecological community develops over time, beginning when some event disrupts or dramatically alters an existing community. Compare primary succession Pioneer species: A species that arrives earliest, beginning the ecological process of succession in a terrestrial or aquatic community. o Communities may undergo shifts Phase shift/ regime shift: A fundamental shift in the overall character of an ecological community, generally occurring after some extreme disturbance, and after which the community may not return to its original state. Also known as a regime shift. Novel communities/ no-analog communities: An ecological community composed of a novel mixture of organisms, with no current analog or historical precedent. o Invasive Species Pose Threats to Communities Stability Introduced species: Species introduced by human beings from one place to another (whether intentionally or by accident). A minority of introduced species may become invasive species. Invasive species: A species that spreads widely and rapidly becomes dominant in a community, interfering with the community's normal functioning. o We Can Respond to Invasive Species with Control, Eradication, or Prevention o Altered Communities can be Restored Restoration ecology: The study of the historical conditions of ecological communities as they existed before humans altered them. Principles of restoration ecology are applied in the practice of ecological restoration. Ecological restoration: Efforts to reverse the effects of human disruption of ecological systems and to restore communities to their condition before the disruption. The practice that applies principles of restoration ecology. • Earth's Biomes Biomes: A major regional complex of similar plant communities; a large ecological unit defined by its dominant plant type and vegetation structure. o Climate helps determine biomes Climate diagrams/climatographs: A visual representation of a region's average monthly temperature and precipitation. Also known as a climatograph. o Aquatic and Coastal Systems Resemble Biomes o We can Divide the World into 10 Terrestrial Biomes Temperate Deciduous Forest: A biome consisting of midlatitude forests characterized by broad-leafed trees that lose their leaves each fall and remain dormant during winter. These forests occur in areas where precipitation is spread relatively evenly throughout the year. Temperate Grasslands: A biome whose vegetation is dominated by grasses and features more extreme temperature differences between winter and summer and less precipitation than temperate deciduous forests. Also known as steppe, prairie. Temperate Rainforest: A biome consisting of tall coniferous trees, cooler and less species-rich than tropical rainforest and milder and wetter than temperate deciduous forest. Tropical Rainforest: A biome characterized by year-round rain and uniformly warm temperatures. Tropical rainforests have dark, damp interiors; lush vegetation; and highly diverse biotic communities. Tropical Dry Forest/Tropical Deciduous Forest: A biome that consists of deciduous trees and occurs at tropical and subtropical latitudes where wet and dry seasons each span about half the year. Also known as tropical deciduous forest. Savanna: A biome characterized by grassland interspersed with clusters of acacias and other trees in dry tropical regions. Desert: The driest biome on Earth, with annual precipitation of less than 25 cm. Because deserts have relatively little vegetation to insulate them from temperature extremes, sunlight readily heats them in the daytime, but daytime heat is quickly lost at night, so temperatures vary widely. Tundra: A biome that is nearly as dry as desert but is located at very high latitudes. Extremely cold winters with little daylight and moderately cool summers with lengthy days characterize this landscape of lichens and low, scrubby vegetation. Boreal Forest/Taiga: A biome of northern coniferous forest. Also known as taiga, boreal forest consists of a limited number of species of evergreen trees, such as black spruce, that dominate large regions of forests interspersed with occasional bogs and lakes. Chaparral: A biome consisting mostly of densely thicketed evergreen shrubs occurring in limited small patches. Its "Mediterranean" climate of mild, wet winters and warm, dry summers is induced by oceanic influences.

Chapter

Biodiversity and conservation biology Biodiversity encompasses multiple levels Biodiversity (biological diversity) the variety of life across all levels of biological organization, and includes diversity in species, genes, populations, communities, and ecosystems Species diversity the number or variety of species found in a particular region. Species richness the number of species evenness (relative abundance) the degree to which species differ in numbers of individuals (greater evenness means they differ less) Species a distinct type of organism, a set of individuals that uniquely share certain characteristics and can breed with one another and produce fertile offspring Genetic diversity encompasses the differences in DNA composition among individuals and this provides the raw material for adaption to local conditions Inbreeding depression occurs when genetically similar parents mate and produce weak or defective offspring Ecosystem diversity refers to the number and variety of ecosystems, but biologist may also refer to the diversity of communities, or habitats within some specified area Benefits of biodiversity Enhances food security Organisms provide drugs and medicines Provides ecosystem services Helps maintain ecosystem function Boosts economies through tourism and recreation People value connections with nature Biodiversity loss and extinction Extinction occurs when the last member of a species dies and the species ceases to exist Local extinction (extirpation) the disappearance of a population from an area, but not the entire species globally Background extinction rate most extinctions preceding the appearance of human beings occur singularly for independent reason at a pace Mass Extinction Events The extinction of a large proportion of the world's species in a very short time period due to some extreme and rapid change or catastrophic event. Earth has seen 5 mass extinction events in the past half-billion years Ordovician, Devonian, Permo-Triassic, End-Triassic, Cretaceous-Paleogene We are currently approaching the sixth Archaeological evidence shows that in a case after case, a wave of extinction followed close on the heels of human arrival on islands and contients j Species loss is accelerating as our population growth and resource consumption put increasing strain on habitats and wildlife. Several major causes of biodiversity loss stand out Habitat Loss Single greatest cause of biodiversity decline Habitat fragmentation the process by which an expanse of natural habitat becomes broken up into discontinuous fragments, often as a result of farming, logging, road building, and other types of human land use Pollution Air pollution degrades forest ecosystems and affects the atmosphere and climate Water pollution impairs fish and amphibians agricultural runoff containing fertilizers, pesticides, and sediments harms many terrestrial and aquatic species Overharvesting Hunting of long-lived and slow to reproduce species Governments have passed laws to stop this Invasive species When non-native species are introduced to new environments, some may become invasive and push native species towards extinction Introductions can be accidental or intentional Climate Change Global impacts As we warm the atmosphere with emissions of greenhouse gases from fossil fuels combustion, we modify climate patterns and increase the frequency of extreme weather events Conservation Biology A scientific discipline devoted to understanding the factors, forces, and processes that influence the loss, protection, and restoration of biodiversity within and among ecosystems Conservation geneticist a scientist who studies genetic attributes of organisms, generally to infer the status of their populations in order to help conserve them Endangered species Endangered Species Act the primary legislation for protecting biodiversity in the US. It offers protection to species that are endangered or threatened Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) protects endangered species by banning international transport of their body parts Convention on Biological Diversity aims to help nations conserve biodiversity, use it in a sustainable manner, and ensure the fair distribution of its benefits Captive breeding individuals are bred and raised in controlled conditions with the intent of reintroducing their progeny into the wild hotspots Biodiversity hotspots a region that supports an especially great number of species that are endemic, found nowhere else in the world Community based conservation is growing When conservation biologists actively engage local people in efforts to protect land and wildlife

Chapter 10

Environmental Hazards and Risk Assessment Physical, cultural, biological, and chemical hazards Environmental toxicology and methodology Environmental Health Assesses environmental factors that influence human health and quality of life Considers both natural and human-caused factors (Does not traditionally take an ecological systems perspective...) Environmental hazards Physical = natural earth processes Physical hazards arise from processes that occur naturally in our environment and pose risks to human life or health Examples Excessive exposure to UV radiation Earthquakes Volcanoes Fires Floods Droughts... We cannot prevent many of these hazards, but we can minimize risk by preparing by practicing emergency plans and avoiding unsafe practices Environmental hazards Biological = result from ecological interactions among organisms Viruses, bacteria, and other pathogens When we get sick from a virus, bacterial infection, or other pathogen, we are suffering parasitism Infectious (communicable, or transmissible) disease A disease in which a pathogen attacks a host Predation (rare) This includes animals Disease is a major focus of environmental health Infectious disease Infectious disease Many emerging/ persistent diseases MDR tuberculosis, HIV, West Nile virus Key factors mobility evolving resistance to antibiotics climate change will expand the range of diseases Environmental hazards Cultural = result from the place we live, our socioeconomic status, our occupation, our behavioral choices We can sometimes minimize other times it is outside our control Smoking Drug use Diet and nutrition Crime Mode of transportation Environmental Hazards Chemical = synthetic or natural compounds that can affect human health Some natural substances that we process for our use (such as hydrocarbons, lead, and asbestos) are also harmful to human health Benzene Criteria air pollutants Urushiol Emissions of microbial metabolism... Natural vs. synthetic? Chemical toxicants also exist naturally and in our food Some scientists believe exposure to natural toxicants dwarfs that of synthetics Others point out natural toxins are more readily metabolized and excreted Key: synthetic chemicals more likely to persist and accumulate Why? Disease and Toxicology Disease causes the vast majority of human deaths worldwide. Noninfectious disease: not spread from person to person, but influenced by genetics, environmental factors, and lifestyle choices. Toxicology is the study of chemical hazards Toxicology is the science that examines how poisonous chemicals affect the health of humans and other organisms Toxicity: toxicology assess and compare substances to see the degree of harm a chemical substance can inflict Toxicant: a toxic substances, or poison Environmental toxicology: toxic substances that come from or are discharged into the environment Toxin: toxic chemicals manufactured in the tissues of living organisms Many environmental health hazards exists indoors Cigarette smoke Radon Lead poisoning Polybrominated diphenyl ethers (PBDEs) In fire retardant computers, TVs, plastics, and furniture that can slowly evaporate throughout the lifetime of the product PBDEs Polybrominated diphenyl ethers = fire-retardent properties Used in computers, televisions, plastics, and furniture Persist and accumulate in living tissue Endocrine disruptor = mimic hormones and interfere with the functioning of animals' endocrine (hormone) systems Toxicology Study of the effects of poisonous substances on humans and other organisms Toxicity = the degree of harm a toxicant can cause "The dose makes the poison" Toxicant = a toxic agent Environmental toxicology Study of toxic substances that come from or are discharged into the environment Studies the health effects on humans, other animals, and ecosystems Focus mainly on humans, using other animals as test subjects Environmental toxicants The environment contains natural chemicals that may pose health risks Synthetic chemicals are increasing in concentration in the environment Environmental toxicants Categories of toxicants Carcinogens = cause cancer Mutagens = cause DNA mutations Can lead to severe problems, including cancer Teratogens = cause birth defects Allergens = overactivate the immune system causing an immune response when one is not necessary Neurotoxins = assault the nervous system Endocrine disruptors = interfere with the endocrine (hormone) system Pathway inhibitors= toxicants that interrupt vital biochemical processes in organisms by blocking one or more steps in important biochemical pathways. Silent Spring and synthetic toxicants In the 1960s, pesticides were mostly untested and were sprayed over public areas, assuming they would do no harm Silent Spring by Rachel Carson (1962) Brought together studies to show DDT risks to people, wildlife, and ecosystems The book generated significant social change Exposure Acute exposure: a person experiences high exposure for short periods of time Discrete events Accidental ingestion Oil spill Chemical spill Nuclear accident Chronic exposure: low exposure over a long period of time Affect organs Smoking Alcohol abuse Toxic Substance and Their Effect on Ecosystem Some toxicants persist in environment Breakdown product: when toxic substances degraded into simpler compounds. These are less harmful than the original substances, but sometimes they are just as toxic as the original chemical Bioaccumulation/Biomagnification Fat-soluble toxicants are stored in fatty tissues Bioaccumulation = toxicants build up in animal tissues Biomagnification = concentrate in top predators Yaqui Valley pesticide study Endocrine disruption toxic substances that interfere with the endocrine system. The endocrine system consists of hormones that travel through the bloodstream at low concentrations and perform many vital functions Theo Colburn wrote Our Stolen Future in 1996 Synthetic chemicals may be altering the hormones of animals This book integrated scientific work from various fields Shocked many readers and brought criticism from the chemical industry Endocrine disruption Endocrine disruption Frogs with gonadal abnormalities Male frogs feminized from atrazine at concentrations far below EPA guidelines PCB-contaminated human babies were born weighing less, with smaller heads Studying Effects of Hazards Human studies rely on case histories, epidemiology and animal testing Case history: the process of observing and analyzing individual patients that sickened. Epidemiological studies: large scale comparisons among groups of people usually contrasting a group known to have been exposed to some hazard against a group that has not Epidemiological studies track the fate of all people in the study for a long period of time (years, decades) and measure the rate at which death, cancer, or other health problems occur in the group Dose-response analysis is a mainstay of toxicology Dose-response analysis: the standard method of testing with lab animals in toxicology Scientist quantify the toxicity of a substance by measuring the strength of its effects or the number of animals affected at different doses. Dose: the amount of substance the test animal receives Response: the type or magnitude of negative effects the animal exhibits as a result Dose-response curve: the data plotted on a graph with does on the x-axis and response on the y-axis Threshold: when responses can only occur above a certain dose Chemical mixes may be more than the sum of their parts Synergistic effects: interactive impacts that are greater that the simple sum of their constituent effects Endocrine disruption Endocrine disruption Research results are uncertain, which is inherent in any young field Negative findings pose economic threats to chemical manufacturers Banning a top-selling chemical could cost a company millions of dollars Bisphenol-A (BPA), found in plastics, can cause birth defects, but the plastics industry protests that the chemical is safe Studies reporting harm are publicly funded, but those reporting no harm are industry funded Risk assessment the quantitative measurement of risk and the comparison of risks involved in different activities or substances together. It is a way to identify and outline problems Risk = the probability that some harmful outcome will result from a given action Exposure causes some probability (likelihood) of harm Probability entails Identity and strength of threat Chance and frequency that an organism will encounter it Amount of exposure to the threat Sensitivity to the threat Perceiving risks Everything we do involves some risk We try to minimize risk, but we often misperceive it Flying versus driving We feel more at risk when we cannot control a situation We fear nuclear power and toxic waste, but not smoking or overeating Risk Perception Activity In groups, discuss the sources of mortality on the form Reach a consensus on the rankings for this set of hazards Report out your ranks for the top 5 hazards Actual risks in U.S. Risk management decisions and strategies to minimize risk. Scientific assessments of risk are considered in light of economic, social, and political needs and values Current US approach Innocent until proven guilty: product assumed safe after limited testing Benefits: technological innovation and economic advancement Disadvantage: putting into wide use some substances that may later on turn out to be dangerous European approach Precautionary principle: extensive testing required to prove a product is safe Assume substances are harmful until they are proven harmless Identifies troublesome toxicants before they are released But, this may impede the pace of technology and economic advance US Federal Agencies Federal agencies apportion responsibility for tracking and regulating synthetic chemicals FDA: food, food additives, cosmetics, drugs, and medical devices EPA: pesticides Occupational Safety and Health Administration (OSHA): workplace hazards Many public health and environmental advocates fear it isn't enough Many synthetic chemicals are not actually tested Only 10% have been tested for toxicity Fewer than 1% are government regulated International regulation Stockholm Convention on Persistent Organic Pollutants (POPs) ratified by 140 nations in 2004 Ends the release of the 12 most dangerous POPs International regulation EU's Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) Program Aims to evaluate and restrict dangerous chemicals while giving industries a streamlined regulatory system Cost to chemical industry 2.8-5.2 billion euros ($3.8-7.0 billion) Savings estimated more than 10 times that in health benefits—but to government and insurance Conclusion International agreements represent a hopeful sign that governments are working to protect society, wildlife, and ecosystems from toxic chemicals and environmental hazards Once all the scientific results are in, society's philosophical approach to risk management will determine what policies are enacted A safe and happy future depends on knowing the risks that some hazards pose and on replacing those substances with safer ones

Chapter 4 PP

Chapter 4: Larger-scale ecology Species interactions Communities Biomes Energy flows Biomass Pyramid Species interactions Competition Food Webs Food webs give a more complete description of natural systems than food chains Food webs are conceptual representations of feeding relationships in a community. Keystone Species Are some species in a community more 'important' than others? Keystone species: A species that has an especially far-reaching effect on a community. Dominant species The kelp is the DS In this case the sea otter is the KS b/c SO eat urchins who eat kelp Kelp forest (with otters) Kelp forest (w/o otters) Keystone vs. Dominant Species Disturbance and Succession Resistance? Resilience? Both?...or Neither? Primary succession: A stereotypical series of changes as an ecological community develops over time, beginning with a lifeless substrate. In terrestrial systems, primary succession begins when a bare expanse of rock, sand, or sediment becomes newly exposed to the atmosphere and pioneer species arrive. Compare secondary succession. Are some species in a community more 'important' than others? Keystone species Dominant species Pioneer species: A species that arrives earliest, beginning the ecological process of succession in a terrestrial or aquatic community. Secondary Succession Resistance and Resilience Resistance Community remains stable despite disturbance Resilience Community returns quickly to original state after disturbance Invasive species Are some species in a community more 'important' than others? Keystone species Dominant species Pioneer species Invasive species: A species that spreads widely and rapidly becomes dominant in a community, interfering with the community's normal functioning. Keystone v. dominate example A keystone is the wedge-shaped stone at the top of an arch that holds its structure together (a). A keystone species, such as the sea otter, is one that exerts great influence on a community's composition and structure (b). Sea otters consume sea urchins, which eat kelp in marine nearshore environments of the Pacific. hen otters are present, they keep urchin numbers down, allowing lush underwater forests of kelp to grow and provide habitat for many other species. hen otters are absent, urchin populations increase and devour the kelp, destroying habitat and depressing species diversity. Intake Pipes Zebra mussels in the Hudson Filter-feeding increased 30 x Effects on invertebrates: Phytoplankton 80% Small zooplankton 76% Large zooplankton 52% Benthic invertebrates 10% What about vertebrates? Fieldwork! Hudson river fish community Response to invasive species? Control Chemical Natural predators Eradication Removal Prevention Ballast water regulations Restoration Ecology Human response to human disturbance Rebuild wetlands (ex: Florida everglades) Restore forests (ex: change logging practices) Restore grasslands (ex: controlled burns, remove livestock) Are all invasive species bad? Although mustangs are not native to the U.S., they exist in several western states, on federally owned land. As an introduced species, what should be done with them? As an exotic species, they should immediately be removed and adopted. As an exotic species, they should immediately be removed and killed. Although they are an exotic species, they are part of our heritage, and should be allowed to stay. They have been here so long, we should just leave them alone. Many countries eat horse flesh, so we should round them up and export them to horse-eating countries. Sustainable Solutions Biomes Recognized by Vegetation Defined by Average T and Ppt T and Ppt = Biome in a Location Terrestrial Biomes Temperate deciduous forest Temperate grassland Temperate rainforest Tropical Rainforest Tropical dry forest Savanna Desert Tundra Boreal forest Chaparral

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Putting it Together Environmental systems, Environmental issues, and Nutrient and energy flows Photosynthesis Organelles called chloroplasts convert Water (H2O) + carbon dioxide (CO2) to sugars (CH2O)n + oxygen (O2). Photosynthesis An autotroph Respiration and heterotrophs Organisms release stored energy via respiration Burns sugar molecules with oxygen, releasing CO2, H2O and stored chemical energy Respiration occurs in both autotrophs and in the heterotrophs (animals, fungi, most microbes) that eat them Cellular respiration The opposite of the equation for photosynthesis. Energy flows, nutrients cycle Organic compounds Compounds based on carbon atoms Very diverse set of compounds Vitally important to life sugars, oils, proteins Macromolecules Major classes: Proteins Nucleic acids Carbohydrates Lipids (The first three are polymers) Proteins Consist of chains of amino acids folded into complex shapes For structure, energy, immune system, hormones, enzymes Nucleic acids Paired strands of nucleotides make up the DNA double helix. Carbohydrates Carbohydrates consist of chains of sugars.  For energy, and structure (cellulose, chitin) Lipids Hydrophobic-do not dissolve in water Include fats and oils; phospholipids; waxes; steroids Chemical structure of DDT Bioaccumulation and Biomagnification A typical polychlorinated biphenyl (PCB) What will happen to this molecule? Building Blocks of Life Organic Matter Carbohydrates Fats and Oils Proteins Nucleic acids Inorganic Matter Macronutrients Nitrogen (N) Phosphorus (P) Sulfur (S) Potassium (K) Micronutrients Calcium (Ca) Iron (Fe) Cobalt (Co) Selenium (Se) ...and several others Liebig's Law of the Minimum Growth of autotrophs limited by nutrient (macro or micro) that's least available Limiting Nutrients Limiting Nutrients Honeydew, baby! Generalized biogeochemical cycle Spontanous flow Non-spontaneous flow Bioavailability Organisms require chemical elements in a specific form to be usable ex: C unavailable to mammals in form of CO2, available in form of C6H12O6 Therefore, conversion of element from one form to another is another important non-spontaneous flow Nitrogen Cycle Phosphorus Cycle Case study: The Gulf Dead Zone Zone of hypoxic water at mouth of the Mississippi River Annual change 1000 to >22,000 km2 A paradox of enrichment... The Mississippi Watershed Satellite photo of nutrient input Nutrient inputs over time How the dead zone forms DO Monitoring Change in area over time Test your understanding What would a major hurricane do? What about a series of moderate hurricanes? What effect will the Deepwater Horizon spill have? Can phenomena flow upriver? How the dead zone forms Gulf oil spill microbiology Salmon as biological pumps

Chapter 4

• Species Interactions o Competition Can Occur When Resources are limited Competition: relationship in which multiple organisms seek the same limited resource Resource partitioning: the process by which species adapt to competition by evolving to use slightly different resources, thus minimizing interference with one another o Predators Kill and Consume Prey Predation: The process in which one species (the predator) hunts, tracks, captures, and ultimately kills its prey. o Parasites Exploit Living Hosts Parasitism: A relationship in which one organism, the parasite, depends on another, the host, for nourishment or some other benefit while simultaneously doing the host harm. Compare mutualism. o Herbivores Exploit Plants Herbivory: the consumption of plants by animals. o Mutualists Help One Another Mutualism: A relationship in which all participating organisms benefit from their interaction. Compare parasitism. Symbiosis: a relationship between different species of organisms that live in close physical proximity. People often use the term "symbiosis" where referring to a mutualism, but symbiotic relationships can be either parasitic or mutualistic Pollination: A plant-animal interaction in which one organism (for example, a bee or a hummingbird) transfers pollen (containing male sex cells) from flower to flower, fertilizing ovaries (containing female sex cells) that grow into fruits with seeds. • Ecological Communities Community: In ecology, an assemblage of populations of organisms that live in the same place at the same time. o Energy passes among trophic level Trophic level: Rank in the feeding hierarchy of a food chain. Organisms at higher trophic levels consume those at lower trophic levels. • Producers (autotroph): an organism that uses energy from sunlight to produce its own food. Includes green plants, algae, and cyanobacteria • Consumers: • Detritivores and Decomposers: an organism such as a millipede or soil insect that scavenges the waste products or dead bodies of other community members...........organism, such as fungus or bacterium, that breaks down leaf litter and other nonliving matter into simple constituents that can be taken up and used by plants o Energy, Numbers, and Biomass Decrease at Higher Trophic Levels Biomass: (1) In ecology, organic material that makes up living organisms; the collective mass of living matter in a given place and time. (2) In energy, organic material derived from living or recently living organisms, containing chemical energy that originated with photosynthesis. o Food Webs Show Feeding Relationships and Energy Flow Food chain: A linear series of feeding relationships. As organisms feed on one another, energy is transferred from lower to higher trophic levels. Compare food web. Food web: A visual representation of feeding interactions within an ecological community that shows an array of relationships between organisms at different trophic levels. Compare food chain. o Some Organisms play Outsized Roles Keystone species: A species that has an especially far-reaching effect on a community. Trophic cascade: A series of changes in the population sizes of organisms at different trophic levels in a food chain, occurring when predators at high trophic levels indirectly promote populations of organisms at low trophic levels by keeping species at intermediate trophic levels in check. Trophic cascades may become apparent when a top predator is eliminated from a system. o Communities Respond to Disturbance in Various Ways Disturbances: An event that affects environmental conditions rapidly and drastically, resulting in changes to the community and ecosystem. Disturbance can be natural or can be caused by people Resistance: The ability of an ecological community to remain stable in the presence of a disturbance. Compare resilience. Resilience: The ability of an ecological community to change in response to disturbance but later return to its original state. Compare resistance. o Succession Follows Severe Disturbance Succession: A stereotypical series of changes in the composition and structure of an ecological community through time. See primary succession; secondary succession. Primary Succession: A stereotypical series of changes as an ecological community develops over time, beginning with a lifeless substrate. In terrestrial systems, primary succession begins when a bare expanse of rock, sand, or sediment becomes newly exposed to the atmosphere and pioneer species arrive. Compare secondary succession. Secondary succession: A stereotypical series of changes as an ecological community develops over time, beginning when some event disrupts or dramatically alters an existing community. Compare primary succession Pioneer species: A species that arrives earliest, beginning the ecological process of succession in a terrestrial or aquatic community. o Communities may undergo shifts Phase shift/ regime shift: A fundamental shift in the overall character of an ecological community, generally occurring after some extreme disturbance, and after which the community may not return to its original state. Also known as a regime shift. Novel communities/ no-analog communities: An ecological community composed of a novel mixture of organisms, with no current analog or historical precedent. o Invasive Species Pose Threats to Communities Stability Introduced species: Species introduced by human beings from one place to another (whether intentionally or by accident). A minority of introduced species may become invasive species. Invasive species: A species that spreads widely and rapidly becomes dominant in a community, interfering with the community's normal functioning. o We Can Respond to Invasive Species with Control, Eradication, or Prevention o Altered Communities can be Restored Restoration ecology: The study of the historical conditions of ecological communities as they existed before humans altered them. Principles of restoration ecology are applied in the practice of ecological restoration. Ecological restoration: Efforts to reverse the effects of human disruption of ecological systems and to restore communities to their condition before the disruption. The practice that applies principles of restoration ecology. • Earth's Biomes Biomes: A major regional complex of similar plant communities; a large ecological unit defined by its dominant plant type and vegetation structure. o Climate helps determine biomes Climate diagrams/climatographs: A visual representation of a region's average monthly temperature and precipitation. Also known as a climatograph. o Aquatic and Coastal Systems Resemble Biomes o We can Divide the World into 10 Terrestrial Biomes Temperate Deciduous Forest: A biome consisting of midlatitude forests characterized by broad-leafed trees that lose their leaves each fall and remain dormant during winter. These forests occur in areas where precipitation is spread relatively evenly throughout the year. Temperate Grasslands: A biome whose vegetation is dominated by grasses and features more extreme temperature differences between winter and summer and less precipitation than temperate deciduous forests. Also known as steppe, prairie. Temperate Rainforest: A biome consisting of tall coniferous trees, cooler and less species-rich than tropical rainforest and milder and wetter than temperate deciduous forest. Tropical Rainforest: A biome characterized by year-round rain and uniformly warm temperatures. Tropical rainforests have dark, damp interiors; lush vegetation; and highly diverse biotic communities. Tropical Dry Forest/Tropical Deciduous Forest: A biome that consists of deciduous trees and occurs at tropical and subtropical latitudes where wet and dry seasons each span about half the year. Also known as tropical deciduous forest. Savanna: A biome characterized by grassland interspersed with clusters of acacias and other trees in dry tropical regions. Desert: The driest biome on Earth, with annual precipitation of less than 25 cm. Because deserts have relatively little vegetation to insulate them from temperature extremes, sunlight readily heats them in the daytime, but daytime heat is quickly lost at night, so temperatures vary widely. Tundra: A biome that is nearly as dry as desert but is located at very high latitudes. Extremely cold winters with little daylight and moderately cool summers with lengthy days characterize this landscape of lichens and low, scrubby vegetation. Boreal Forest/Taiga: A biome of northern coniferous forest. Also known as taiga, boreal forest consists of a limited number of species of evergreen trees, such as black spruce, that dominate large regions of forests interspersed with occasional bogs and lakes. Chaparral: A biome consisting mostly of densely thicketed evergreen shrubs occurring in limited small patches. Its "Mediterranean" climate of mild, wet winters and warm, dry summers is induced by oceanic influences.

Chapter 13

Chapter 13: Air Pollution Outdoors: Criteria pollutants and the Clean Air Act Indoors: Smoke, Radon, VOCs,... Textbook The Atmosphere the layer of gases that envelops our planet. It moderates our climate, provides oxygen, shields us from meteors and from hazardous solar radiation, and transports and recycles water and nutrients. The atmosphere is layered Troposphere: the bottommost layer. Air movement drives the planet's weather. Is thin compared to the other layers, but it contains three-quarters of the atmosphere's mass. Tropopause limits mixing between the troposphere and the stratosphere. Stratosphere: middle. Drier and less dense than the troposphere. Its gases experience little vertical mixing so once substances (including pollutants) enter it, they tend to remain for a long time. Warms the altitude (it's ozone and oxygen absorbs the sun's ultraviolet radiation) by absorbing and scattering UV radiation, it reduces the amount that reaches the Earth's surface. Ozone layer above sea level, that contains most of the ozone in the atmosphere Mesosphere: above the stratosphere. Temperature decreases with altitude and where incoming meteors burn up Thermosphere: above the mesosphere Exosphere: merges into space The sun influences weather and climate A large amount of energy from the sun constantly bombards the upper atmosphere. 70% of the solar energy is absorbed by the atmosphere and planetary surface (the rest is reflected back into space) Land and surface water absorb solar energy and the emit thermal infrared radiation, which warms the air and causes some water to evaporate. As a result, air near Earth's surface tends to be warmer and moister than air at higher altitudes This causes convective circulation a circular current of air, water, magma ,etc) driven by temperature differences. In the atmosphere, warm air rises into regions of lower atmospheric pressure, where it expands and cools and then Inversions affect air quality Large-scale circulation systems produce global climate patterns Stratospheric ozone depletion: a global scale problem What is stratospheric ozone? What are ozone depleting substances? What solutions have we developed? The atmosphere is layered Earth's four atmospheric layers have different temperatures, densities, and chemical composition Troposphere Bottommost layer (11 km [7 miles]) Responsible for Earth's weather The air gets colder with altitude Tropopause The boundary that limits mixing between the troposphere and stratosphere The atmosphere is layered Stratosphere 11-50 km (7-31 mi) above sea level Drier and less dense, with little vertical mixing Gets warmer with altitude Ozone layer Blocks UV radiation Mesosphere Low air pressure Gets colder with altitude Thermosphere Top layer Ozone depletion Ozone in the lower stratosphere absorbs the sun's ultraviolet (UV) radiation UV radiation can damage tissues and DNA Ozone-depleting substances Human-made chemicals that destroy ozone The major ODS chemicals: Halocarbons Human-made compounds made from hydrocarbons with added chlorine, bromine, or fluorine Synthetic chemicals deplete stratospheric ozone Chlorofluorocarbons (CFCs) Halocarbons used as refrigerants, in fire extinguishers, in aerosol cans, etc. They stay in the stratosphere for a century Sunlight releases chlorine atoms that split ozone Ozone hole Decreased ozone levels over Antarctica We are solving ozone depletion with the Montreal Protocol Montreal Protocol (1987) 196 nations agreed to cut CFC production in half by 1998 Later agreements deepened cuts, advanced timetables, and addressed other ozone-depleting chemicals Industry shifted to safer alternative chemicals We stopped the Antarctic ozone hole from getting worse Challenges still face us CFCs will remain in the stratosphere for decades It can serve as a model for international environmental cooperation The ozone layer has stopped growing Outdoor (ambient) air pollution Air pollutants: gases and particulate material added to the atmosphere Can affect climate Can harm people or other organisms Natural sources Winds blowing over arid terrain huge amounts of dust Volcanoes particulate matter, sulfur dioxide, and other gases. Fires soot and gases. Exacerbated by farming, grazing, erosion, desertification, clearing forests Anthropogenic air pollution Sources Point sources: specific spots where large quantities of pollutants are discharged (power plants and factories) Non-point sources: more diffuse, consisting of many small sources (automobiles) Types of pollutants Primary pollutants: directly harmful and can react to form harmful substances (soot and carbon dioxide) Secondary pollutants: form when primary pollutants interact or react with constituents of the atmosphere Air pollution operates at many scales (duration and area) Clean Air Act (CAA) Passed in 1970 (amended 1990) Provides: NAAQS for criteria air pollutants Reduction from mobile sources New stationary source performance standards Limits on emissions Funds for pollution-control research Right to sue polluters The EPA sets standards Environmental Protection Agency (EPA) sets nationwide standards State Implementation Plans (SIPs) States monitor air quality and develop, implement, and enforce regulations. If a state's plans are not adequate, the EPA can take over enforcement. Six EPA criteria pollutants Carbon monoxide (CO) Sulfur dioxide (SO2) Particulate matter Nitrogen oxides (NOx) Volatile organic compounds (VOCs) Lead Carbon Monoxide-CO Colorless, odorless Binds strongly with hemoglobin Blocks transport of oxygen by the blood Headaches, dizziness, and death Produced by incomplete combustion Mobile & stationary sources Industrial Smog Sulfur Dioxide-SO2 Constricts airways, changes respiratory and pulse rates 50,000 deaths/year U.S. Sources vary Volcanic eruptions and sea spray Fossil Fuel Combustion Smelting Ores Mixes with water to make sulfuric acid Particulate Matter Mixture of solid particles and liquid droplets Aerosol Dust Fumes Mist Smoke or soot Categorized by size PM10 PM2.5 Size of Particulates Effects of Particulates Respiratory ailments Bronchitis, pneumonia, emphysema, asthma Genetic mutations "Weekend Effect" Nitrogen Oxides-NOx NO, NO2, NO3, N2O, N2O3, N2O4, and N2O5 Effects Some can form nitric acid Precursor to many other pollutants Sources Thermal NOx when fuel is burned with air at high temperatures This leads to burning nitrogen gas also... Volatile Organic Compounds (VOCs) Carbon-based chemicals from a variety of sources Solvents, auto exhaust, paints, industrial activity, consumer products Some are directly toxic Benzene, formaldehyde, many others Can also react to produce secondary pollutants, such as tropospheric ozone (O3) Photochemical Smog Ozone as a pollutant Tropospheric ozone (O3): a colorless gas with a strong odor Secondary pollutant created from interactions of sunlight, heat, nitrogen oxides, volatile carbons A major component of smog Poses a health risk as a result of its instability Most frequently exceeds the EPA standard Stratospheric ozone is a different story—more later Lead Elemental lead added to gas and used in industrial metal smelting Bioaccumulates and causes nervous system malfunction Banned in gasoline in developed, but not in developing, countries The CAA is successful Innovations driven by CAA Cleaner-burning vehicles and catalytic converters decrease carbon monoxide. Permit-trading programs and clean coal technologies reduce SO2 emissions. Phaseout of leaded gasoline Improved technologies and federal policies Scrubbers: technologies that chemically convert or physically remove pollutants before they leave the smokestacks Scrubber technology Toxic substances also pollute Toxic air pollutants: substances known to cause cancer, reproductive defects, and/or neurological, development, immune system, or respiratory problems The Clean Air Act identifies 188 toxic pollutants. Emissions decreased 35% between 1990 and 2002. CAA is controversial President G.W. Bush proposed modifications Abolish 'New source reviews': during which old utility plants have to install the best available technology when upgrading Clear Skies Initiative (2003) would have: Allowed 42 million more tons of pollution per yr raised current cap on nitrogen oxide pollution, allowing 68% more NOx pollution delayed improvement of sulfur dioxide (SO2) pollution levels required by CAA delayed enforcement of smog-and-soot pollution standards until 2015 Transboundary issues Acidic deposition: the deposition of acid, or acid-forming pollutants, from the atmosphere onto Earth's surface Acid rain: precipitation of acid Atmospheric deposition: the wet or dry deposition on land of pollutants Acid rain from NOx and SO2: Distance effects Acid rain inthe US Acid Deposition and Buffering Buffering of acid rain takes place when limestone (CaCO3) supplies bicarbonate ions (HCO3-) The bicarbonate ion (HCO3-) combines with hydrogen ions to neutralize acid rain Geographic differences In areas that have large amounts of calcium carbonate (western U.S.) acidity is buffered In other areas, such as New England or upstate NY, acid precipitation quickly lowers pH Effects Nutrients are leached from topsoil. Metal ions (aluminum, zinc, etc.) converted into soluble forms that pollute water. Damages agricultural crops Affects surface water and kills fish Widespread tree mortality Erodes stone buildings, corrodes cars, erases writing on tombstones and other monuments Developing nations Factories and power plants have little or no pollution control. Wood and charcoal are used to cook and heat homes. Global patterns in air pollution Indoor air pollution Indoor air contains higher concentrations of pollutants than outdoor air. The average U.S. citizen spends 90% of the time indoors. 6,000 people die per day from indoor air pollution Indoor air pollution Secondhand smoke Eye, nose, and throat irritation, asthma, cancer Radon radioactive gas resulting from natural decay of rock, soil, or water 20,000 deaths a year in the U.S. Volatile organic compounds (VOCs) Released by everything from plastics and oils to perfumes and paints some are carcinogenic, some are toxic through other pathways Organisms pathogenic bacteria, mold, fungi Sources of indoor air pollution Indoor air pollution in the developing world Homes have little to no ventilation... ...wood, charcoal, dung for fuel... ...PM and carbon monoxide estimated 4.3 million deaths per year (more than HIV, malaria, tuberculosis) Multiple Choice HW Lead: Before the 1980s, gasoline combustion was a major source of this pollutant Tropospheric ozone: This pollutant's chemical structure is three bonded oxygen atoms. Its concentration is strongly influenced by sunlight levels and air temperature. Particulate Matter: Pollutants in this category are classified according to diameter. Carbon Monoxide: This pollutant deprives organisms of oxygen by binding to the hemoglobin in red blood cells. Nitrogen dioxide: This pollutant contributes to the formation of photochemical smog and acid deposition. Sulfur dioxide: A very high percentage of the emissions of this pollutant comes from coal combustion. Which of the following layers of the atmosphere is responsible for the weather that we experience on the surface of Earth? Troposphere Which gas makes up 78% of the molecules in the atmosphere? N2—nitrogen What process depends upon the cyclical, vertical movement of air currents: sinking cold, dense; and rising warm, less dense air masses? Convective circulation Which of the following can trap pollutants at ground level and cause dangerous smog? Thermal inversions Point sources of air pollution are __________. specific spots--such as a factory's smokestacks--where large quantities of pollution are discharged A __________ pollutant interacts with a part of the atmosphere and becomes a __________ pollutant. Primary; secondary The EPA tracks six "criteria" air pollutants. Which of these is true of the criteria air pollutants? Total emissions of the six have declined by over 50% since 1970 What releases NO and VOC into the atmosphere, initiating the formation of photochemical smog in cities like Los Angeles and Tehran? Vehicle exhaust Photochemical smog Concentrations are elevated by hot, sunny days A reaction between pollutants and atmospheric compounds that creates over 100 different chemicals: Most pronounced in cities prone to inversion events: Acid disposition Forms from emissions of sulfur dioxide: Leaches plant nutrients from soils: What is largely responsible for the ozone hole? chlorofluorocarbon refrigerants (CFCs) ozone is made of __________ and is broken down by __________. Oxygen; chlorine In which way does acid deposition originate? Through fossil fuel combustion by cars, electric utilities, and industrial facilities What happens when acids from acid deposition hit topsoil? Plants and soil organisms are harmed Most of the indoor air pollution in developing countries comes from burning fuelwood Which two pollutants are the top two responsible for lung pollution in the United States? Cigarette smoke and radon gas

Chapter 14 again

Chapter 14: Global Climate Change Causes Consequences Solutions Rising seas flood the Maldives Independent nation of islands in the Indian Ocean The islands will be submerged by rising seas accompanying global climate change The government has already evacuated residents from of the lowest-lying islands Next week: What can or should be done to address this? What is climate change? Climate an area's long-term atmospheric conditions includes temperature, precipitation, & storm frequency Global climate change Describes an array of changes in aspect of Earth's climate, such as temperature, precipitation, and the frequency and intensity of storms Change in Earth's climate over time via natural processes throughout the history of earth Increasingly affected by human activity Global warming an increase in Earth's average temperature Primary determinants of climate sun supplies most of our planet's energy without it, the Earth would be dark and frozen atmosphere Earth's atmosphere (and clouds) can both absorb and reflect solar radiation without it, the Earth's temperature would be much colder oceans shape climate by storing and transporting heat and moisture Solar output influences climate The Sun varies in the radiation it emits Variation in solar energy (i.e., solar flares) has not been great enough to change Earth's temperature Milankovitch cycles Periodic changes in Earth's rotation and orbit around the Sun Alter the way solar radiation is distributed over Earth's surface Trigger long-term climate variation such as periodic glaciation Fate of Incoming Solar Energy Heat Balance of Earth Work Done by Incoming Energy Heat Drives Convection Cells Convection Cells Drive Rainfall Convection Cells Drive Winds Winds Drive Ocean Currents Ocean absorption buffers climate Ocean water exchanges tremendous amounts of heat with the atmosphere, and ocean currents move energy from place to place Ocean holds 50 times more carbon than the atmosphere and absorbs it from the atmosphere Buffering against rapid global warming But warmer oceans absorb less CO2 gases are less soluble in warmer water Positive feedback effect Ocean Currents Drive Thermohaline Circulation Thermohaline circulation Global current system in which warmer, fresher water moves along the surface; and colder, saltier water moves deep beneath the surface Warm surface water carries heat to Europe North American Deep Water (NADW) = the deep portion of the thermohaline circulation, consisting of dense, cool water that sinks Thermohaline circulation Some data suggest thermohaline circulation is slowing Why? If Greenland's ice melts, freshwater runoff would dilute ocean waters, making them less dense This would disrupt NADW Greenhouse gases Greenhouse gases: a gas that absorbs infrared radiation released by Earth's surface and then warms the surface and troposphere by emitting energy, thus giving rise to the greenhouse effect Atmospheric gases that absorb infrared radiation Include water vapor(H2O), ozone (O3), carbon dioxide(CO2), nitrous oxide (N2O), methane (CH4), and chlorofluorocarbons (molecules of C + Cl and/or F attached) Bonds between atoms in a molecule absorbe radiation greenhouse gases re-emit some of this energy as infrared (heat) energy Heat Balance of Earth The Greenhouse Effect After absorbing radiation, greenhouse gases re-emit infrared energy Some energy is lost to space... ...But some energy travels back downward, warming the atmosphere and planet's surface Key factor is the amount of heat re-emitted by atmosphere Too little? = Ice Ages Just right? = Historic climate Too much? = current (and past) warming trends Are all molecules the same? U.S. emissions of major greenhouse gases CO2 is primary concern Extremely abundant The major contributor to global warming Long residence time in atmosphere Human activities have boosted atmospheric concentrations from 280 parts per million (ppm) to 400 ppm Highest levels in more than 650,000 years What causes elevated CO2? Burned fossil fuels Transferred large amounts of carbon dioxide from lithospheric reservoirs into the atmosphere Deforestation Forests serve as sinks for recently active carbon Their removal reduces the biosphere's ability to absorb carbon dioxide from the atmosphere Other greenhouse gases Methane fossil fuel deposits, livestock, landfills, and crops such as rice Nitrous oxide feedlots, chemical manufacturing plants, auto emissions, and synthetic nitrogen fertilizers Ozone risen due to photochemical smog Halocarbon gases (CFCs) are declining due to the Montreal Protocol Water vapor Can re-emit infrared, and hold heat energy... ...and could increase cloudiness, which might slow global warming by reflecting more solar radiation back into space Aerosols may cool atmosphere Microscopic droplets and particles that have either a warming or cooling effect Soot, or black carbon aerosols, cause warming by absorbing solar energy But, most tropospheric aerosols cool the atmosphere by reflecting the Sun's rays Sulfate aerosols produced by fossil fuel combustion may slow global warming, at least in the short term Volcanic eruptions reduce sunlight reaching the earth and cool the Earth Radiative Forcing (watts per m2) Radiative forcing The change in energy content caused by a given factor Positive forcing warms the surface Negative forcing cools the surface Compared with the pre-industrial Earth, Earth is experiencing radiative forcing of +1.6 watts/m2 This is sufficient to alter the global climate What about the past? Proxy indicators Ice caps, ice sheets, and glaciers hold clues to Earth's climate Trapped bubbles in ice cores show atmospheric composition, greenhouse gas concentration, temperature trends, snowfall, solar activity, and frequency of fires Other proxy indicators Scientists need to combine multiple records to get a global perspective Cores in sediment beds preserve pollen grains and other plant remnants Tree rings indicate age, wetness of the season, droughts, and seasonal growth Researchers also gather data on past ocean conditions from coral reefs What about the present? Concentrations of CO2 have increased over 21% just since the mid-1950s Other greenhouse gasses also show rapid increases Methane Nitrous oxide Sulfur compounds Climate Models Components Feedbacks Thresholds What about the future? Coupled general circulation models (climate models) Computer simulations of climate trends Becoming more reliable in predicting climate change How do we make predictions? Climate models! What do we need? Initial conditions Complex climate system Feedbacks Threshold effects Emissions scenarios Radiative forcing Climate models: Feedback (+) Melting of glaciers and ice caps Water vapor Decay of biomass Forest growth replacing tundra Release of methane CO2 dissolved in oceans Glacial descent or destabilization Climate models: Feedback (-) Cloud formation Photosynthesis Infrared radiation to space Increased snowfall Disrupted thermohaline circulation Threshold Effects? How far can the climate system change before it 'breaks' in some way? Ex: Interrupting thermohaline current in global ocean system that eliminates NADW—cooling Europe to a subarctic tundra biome Thermohaline Circulation Net primary productivity Results from three simulations Figure (a) shows natural climate factors only Figure (b) shows only human factors Emissions of greenhouse gases Figure (c) shows both factors Which of these would NOT contribute to a global increase in temperature? Planting trees Switching from fossil fuels to _____ energy would significantly decrease the release of carbon dioxide into the atmosphere. Solar, nuclear, and geothermal Which three factors have the greatest effect on Earth's climate? The sun, the atmosphere, and the ocean What is the greenhouse effect? A warming of Earth's atmosphere by greenhouse gases that trap reflected heat rather than allow it to escape into space Which of the following contributes to atmospheric cooling? aerosols (particularly sulfur compounds) and dusts Scientists evaluate concentrations of gases and other atmospheric constituents from the distant past by examining which of the following? Gas bubbles trapped in ice What initiative or group is responsible for the most reviewed and widely accepted reports that we have on climate change? Intergovernmental Panel on Climate Change (IPCC) Why are over one-sixth of the world's people at risk for running out of drinking water? Glaciers in many areas are melting How are warming temperatures causing a vicious cycle (positive feedback) that is leading to enhanced warming? Ice and snow reflect light, and as they melt, Earth absorbs more of the sun's rays How is global warming most significantly affecting coral reefs and sea life? Increase concentrations of carbon dioxide are being absorbed by the oceans. Factors that contribute to warming Tropospheric ozone (O3) Carbon dioxide (CO2) from fossil fuel combustion Methane (CH4) from decomposition and feedlots Nitrogen oxides (N2O) from denitrification and fossil fuel combustion Parts of Earth's surface with low reflectivity (low albedo) Black carbon aerosols and soot particles Factors that contribute to cooling Parts of Earth's surface with high reflectivity (high albedo) Condensed water vapor (cloud albedo) Decrease plant growth decrease CO2 decrease H2O decrease sunlight Increase plant growth increase CO2 increase H2O increase sunlight What two processes emit the most carbon in the United States? Electricity generation and transportation Which greenhouse gas is produced by the raising of cattle? Methane Which of the following is an example of mitigation rather than adaptation for global climate change? building more solar panels to generate electricity instead of more coal-fired power plants

Chapter 3 PP

Chapter 3: Evolution, Ecology, and Biodiversity Life: an evolutionary play on an ecological stage The phylogeny (tree!) of life Population ecology The Play: Evolution Evolution and natural selection Evolution = genetic (DNA) change in a population of organisms across generations Doesn't happen to individual organisms; it happens in groups Generations can be hours, months, years, etc Natural selection = process by which traits that provide an advantage in survival or reproduction are passed on to future generations This alters the genetic makeup of populations over time Mechanisms of evolution Gene flow: several individuals are entering a new population Natural selection: resembling other things for protection; attraction; special features/characteristics Genetic drift: some individuals reproduce by chance while others do not Natural selection shapes diversity Charles Darwin and Alfred Russell Wallace independently proposed natural selection to explain the variety of living things. A trait that promotes success in a given habitat is called an adaptive trait or an adaptation. Organisms therefore differ in relative fitness Misconception: evolution always favors complexity/increasing size/etc... A trait that is adaptive in one location or season may prove maladaptive in another... Evolution can favor simplicity, or different traits in different settings Mutation and genetic variation For a trait to be heritable, genes in an organism's DNA must code for the trait. Mutations are accidental changes in DNA. Mutations that are not lethal provide the genetic variation on which natural selection acts. Misconception: Organisms do not 'mutate' in a direction of greater fitness Mutations provide the raw material for evolutionary change. Putting it together The Ecological Theater and the Evolutionary Play G. Evelyn Hutchinson, 1965 'Nothing in Biology Makes Sense Except in the Light of Evolution' Theodosius Dobzhansky, 1973 Habitat and niche Habitat (where an organism lives) = the specific environment where an organism lives including living and nonliving elements: rocks, soil, plants, etc... Niche (what an organism does) = an organism's functional role (feeding, flow of energy and matter, interactions with other organisms, etc.) Specialists = organisms with narrow breadth and thus very specific requirements Pandas can only eat bamboo and can only live in areas with bamboo Endangered species tend to be more likely to be specialists Generalists = have much broader niches Humans because we can live almost anywhere and eat almost anything Central Case: Striking Gold in a Costa Rican Cloud Forest The golden toad of Monteverde Discovered 1964 Disappeared 25 years later. Warming and drying of the forest was likely responsible Golden toads of Monteverde Species and Speciation A species is a particular type of organism; a population or group of populations whose members share certain characteristics and can freely interbreed with one another and produce fertile offspring. Speciation: The process by which new species come into being It is an evolutionary process that has given Earth its current species richness—more than 1.5 million described species Allopatric speciation Start with a single interbreeding population... ...then divided by a barrier... Allopatric speciation Allopatric speciation ...The two populations adapt independently, diverging in their traits... ...Then populations reunited when barrier removed. Phylogenetic trees Life's diversification results from countless speciation events over vast spans of time. Evolutionary history of divergence is illustrated with phylogenetic trees. Similar to family genealogies, these show relationships among organisms. The Tree of Life By studying extant species or their genes we can infer relationships among major groups of living organisms There has been a single origin of life on earth-one lineage with many branches Phylogenetic trees We can zoom in on any group to view a more detailed tree for those organisms Phylogenetic trees Zooming in on the vertebrates... ...and so on The Stage: Ecology Life's hierarchy Ecologists deal with levels of organization from organisms on up They attempt to describe the distribution and abundance of organisms Population ecology Population ecologists investigate changes in population size (N) over time Several attributes help predict population dynamics (dN/dt): Current population size Population density Population distribution Sex ratio Age structure Birth and death rates Population growth Populations may grow, shrink, or remain stable, depending on: (crude birth rate + immigration rate) - (crude death rate + emigration rate) = dN/dt Change over time How quickly are populations changing Age structure Exponential growth Some populations increase by exponential growth: Growth by a fixed percentage, rather than a fixed amount. Similar to growth of money in a savings account Exponential growth Exponential growth produces J-shaped curves of population size vs. time Nt = N0ert or dN/dt = rN Limits on growth? The Elephant Problem - Darwin, 1859 http://www.athro.com/evo/elframe.html Limiting factors restrain exponential growth, slowing the growth rate down. Population levels off at a carrying capacity K = the maximum population size of a given species an environment can sustain Population growth rate (dN/dt) depends on N Logistic growth Density dependence limits growth The condition of a limiting factor whose effects on a population increase or decrease depending on the population density. Compare density-independent factor. Often, survival or reproduction lessens as populations become more dense. 'density-dependent factors' (disease, predation, etc.) key is these factors link b and/or d to N Other factors affect b, d regardless of density and are 'density-independent factors' (e.g., catastrophic weather events). Logistic growth Population oscillations Dampened oscillations Population growth: Crashes Reproductive strategies Species differ in strategies for producing young. Some produce lots of young (insects, fish, frogs, plants) and have high biotic potential. Others, such as mammals and birds, produce few young... ...but give them more care, resulting in better survival. r- vs. K-selected species r-selected species Many offspring Fast growing No parental care K-selected species Few offspring Slow growing Parental care Terms come from r = intrinsic rate of population increase. (Populations can grow fast, have high r.) Exponential growth K = carrying capacity. (Populations stabilize near K.)

Chapter 2 PP

Complex Systems Why are environmental issues often difficult to explain and to solve? How does science study complexity? Outline What are systems? Storage and flows Properties and behaviors Relationships between parts of a system How can we study systems? Why are systems difficult to understand and predict? What are Systems? Collection of parts Parts Linkages Interact in an organized way Behave in regular, recognizable patterns... ...or chaotic patterns Random versus Predictable Types of Flow Spontaneous Flow From high concentration to low Energy dissipated Non-Spontaneous Flow From low concentration to high Requires energy input System Properties Stability Resistance Resilience Complexity Homeostasis The ability of a system to maintain it's behavior when disturbed Measured by constancy in value of a certain storage or flow (set point) Demonstration Tennis balls and kitchen hardware Complexity Parts can have either positive or negative effects on other components Complexity Parts can have either positive or negative effects on other components Effects can be linear or non-linear Parts can be connected in reticulated patterns Feedback Loops A negative feedback loop in which output of one type acts as input that moves the system in the opposite direction. The input and output essentially neutralize each other's effects, stabilizing the system. Blood sugar and insulin Homeostatic something... The ability of a biological system to maintain its behavior when disturbed Measured by constancy in value of a certain storage of flow (set point) Analogous to a room's thermostat Negative feedback describes many homeostatic mechanisms in organisms Complexity Parts can have either positive or negative effects on other components Effects can be linear or non-linear Parts can be connected in reticulated patterns Feedback loops Systems have multiple storages and flows Hierarchies and connected subsystems Approaches to Science Inquiry Reductionist Approach Premise: break it into its parts and study parts separately. Goal: to reveal cause-effect relationships Key Tools: controlled experiments with dependent and independent variables Approaches to Science Inquiry General Systems Theory Premise: patterns and connections are key features of interest Goal: reveal relationships, structures, and interdependence Key Tools: models of natural phenomena Simulation Models Mathematical representations providing a simplified version of reality How to? Choose which storages and flows to include Quantify the nature (+ or -) and the strength (+ or +) of the relationships Calibrate or validate the model using data (real-world observations) Scenario Analysis ("What if?") Why are Systems Difficult to Understand and Predict? Complexity Impacts stability, resistance, and resilience Prevents intuitive understanding Time lags Time lag refers to the period that lapses between a cause and an effect;Long lag times make it difficult to establish cause and effect; Long lag times also diminish effectiveness of environmental policy Distance effects Distance refers to the separation in space between a cause and an effect. Smoke stacks and acid rain Hierarchies Subsystems Connections between systems Why are Systems Difficult to Understand and Predict? Non-linear functions Threshold effects Chaos theory Variability in parameter values Difficulty in estimation Prediction of a range of outcomes Stochasticity Shit happens

Chapter 2

Earth's Environmental Systems System: a network of relationships among parts, elements, or components that interact with and influence one another through the exchange of energy, matter, or information Lithosphere: the rock and sediment beneath our feet, the planet's uppermost mantle and crust Atmosphere: composed of the air surrounding our planet Hydrosphere: encompasses all water-salt or fresh; liquid, ice, or vapor- in surface bodies, underground, and in the atmosphere Biosphere: consists of all planet's organisms and the abiotic (non-living) portions of the environment with which they interact o Systems involve feedback loops Feedback loop: a system's output can serve as input to the same system, a circular process Negative feedback loop: A feedback loop in which output of one type acts as input that moves the system in the opposite direction. The input and output essentially neutralize each other's effects, stabilizing the system. Compare positive feedback loop. Dynamic equilibrium: The state reached when processes within a system are moving in opposing directions at equivalent rates so that their effects balance out. Homeostasis: The tendency of a system to maintain constant or stable internal conditions. Positive feedback loops: A feedback loop in which output of one type acts as input that moves the system in the same direction. The input and output drive the system further toward one extreme or another. Compare negative feedback loop. o Environmental Systems Interact Runoff: The water from precipitation that flows into streams, rivers, lakes, and ponds, and (in many cases) eventually to the ocean. Airshed: The geographic area that produces air pollutants likely to end up in a waterway. Eutrophication: The process of nutrient enrichment, increased production of organic matter, and subsequent ecosystem degradation in a water body. • Matter, Chemistry, and the Environmental Matter: All material in the universe that has mass and occupies space. See law of conservation of matter. Chemistry: The study of the different types of matter and how they interact. Law of conservation of matter: The physical law stating that matter may be transformed from one type of substance into others, but that it cannot be created or destroyed o Atoms and elements are chemical building blocks Element: a fundamental type of matter, a chemical substance with a given set of properties, that cannot be chemically broken down into substances with either properties Atoms: the smallest unit that maintains the chemically properties of an element Protons: positively charged particles in the atom's nucleus (its dense center) Neutrons: particles lacking electric charge in their nuclei Electrons: A negatively charged particle that moves around the nucleus of an atom. • ((hydrogen, oxygen, silicon, carbon, and nitrogen are abundant elements on the planet))\ • ((phosphorous, nitrogen, calcium, and carbon are nutrients because they are elements that organisms need for survival)) • nutrients: An element or compound that organisms consume and require for survival. Isotopes: One of several forms of an element having differing numbers of neutrons in the nucleus of its atoms. Chemically, isotopes of an element behave almost identically, but they have different physical properties because they differ in mass. Ions: An electrically charged atom or combination of atoms. o Atoms bond to form molecules and compounds Molecules: A combination of two or more atoms. Chemical formula: A shorthand way to indicate the type and number of atoms in a molecule using numbers and chemical symbols. Compound: A molecule whose atoms are composed of two or more elements. Water: A compound composed of two hydrogen atoms bonded to one oxygen atom, denoted by the chemical formula H2O. Carbon dioxide: a compound that consists of one carbon atom bonded to two oxygen atoms C2O Ionic bonds: A type of chemical bonding where electrons are transferred between atoms, creating oppositely charged ions that bond due to their differing electrical charges. Table salt, or sodium chloride, is formed by the bonding of positively charged sodium ions with negatively charged chloride ions. Covalent bonds: A type of chemical bonding where atoms share electrons in chemical bonds. An example is a water molecule, which forms when an oxygen atom shares electrons with two hydrogen atoms. Solution: elements, molecules, and compounds that come together without chemically bonding Methane: a colorless gas produced primarily by anaerobic decomposition. The major constituent of natural gas and greenhouse gas that is molecules for molecule more potent than carbon dioxide Ozone: a molecule consisting of three atoms of oxygen. Absorbs UV radiation in the stratosphere o The pH scale describes acids and bases Acidic: the property of a solution in which the concentration of hydrogen ions is greater than the concentration of hydroxide ions Neutral: 7 pure water Basic: the property of a solution in which the concentration of hydroxide ions is greater than the concentration of hydrogen ions. o Matter is composed of organic and inorganic compounds organic compounds: A compound made up of carbon atoms (and, generally, hydrogen atoms) joined by covalent bonds and sometimes including other elements, such as nitrogen, oxygen, sulfur, or phosphorus. The unusual ability of carbon to build elaborate molecules has resulted in millions of different organic compounds showing various degrees of complexity. Hydrocarbon: An organic compound consisting solely of hydrogen and carbon atoms. o Macromolecules are building blocks of life Polymers: A chemical compound or mixture of compounds consisting of long chains of repeated molecules. Important biological molecules, such as DNA and proteins, are examples of polymers. Macromolecules: A very large molecule, such as a protein, nucleic acid, carbohydrate, or lipid. Carbohydrates: An organic compound consisting of atoms of carbon, hydrogen, and oxygen. Proteins: A macromolecule made up of long chains of amino acids. Nucleic acids: A macromolecule that directs the production of proteins. Includes DNA and RNA. Genes: A stretch of DNA that represents a unit of hereditary information. Lipids: chemically diverse groups of compounds, classified together because they do not dissolve in water (fats and oils) Cells: The most basic organizational unit of organisms. • Energy Fundamentals Energy: The capacity to change the position, physical composition, or temperature of matter; a force that can accomplish work Potential energy: Energy of position. Compare kinetic energy. Kinetic energy: Energy of motion. Compare potential energy. Chemical energy: Potential energy held in the bonds between atoms. o Energy is always conserved but it changes in quality First law of thermodynamics: The physical law stating that energy can change from one form to another, but cannot be created or lost. The total energy in the universe remains constant and is said to be conserved. Second law of thermodynamics: The physical law stating that the nature of energy tends to change from a more-ordered state to a less-ordered state; that is, entropy increases. o Light Energy from the sun powers most living systems Autotrophs (primary producer): An organism that can use the energy from sunlight to produce its own food. Includes green plants, algae, and cyanobacteria. Producer: An organism that uses energy from sunlight to produce its own food. Includes green plants, algae, and cyanobacteria. See autotroph. Photosynthesis: The process by which autotrophs produce their own food. Sunlight powers a series of chemical reactions that convert carbon dioxide and water into sugar (glucose), thus transforming low-quality energy from the sun into high-quality energy the organism can use. Compare cellular respiration. o Cellular respiration release chemical energy Cellular respiration: The process by which a cell uses the chemical reactivity of oxygen to split glucose into its constituent parts, water and carbon dioxide, and thereby release chemical energy that can be used to form chemical bonds or to perform other tasks within the cell. Compare photosynthesis. Heterotrophs (consumer): An organism that consumes other organisms. Includes most animals, as well as fungi and microbes that decompose organic matter. • Ecosystems ecosystem: consists of all organisms and nonliving entities that occur and interact in a particular area at a particular time o Energy flows and matter cycles through ecosystems estuary: An area where a river flows into the ocean, mixing fresh water with salt water. o Sunlight is converted to chemical energy in biomass Primary production: The conversion of solar energy to the energy of chemical bonds in sugars during photosynthesis, performed by autotrophs. Compare secondary production. Gross primary production: The energy that results when autotrophs convert solar energy (sunlight) to energy of chemical bonds in sugars through photosynthesis. Autotrophs use a portion of this production to power their own metabolism, which entails oxidizing organic compounds by cellular respiration. Compare net primary production. Net primary production: The energy or biomass that remains in an ecosystem after autotrophs have metabolized enough for their own maintenance through cellular respiration. Net primary production is the energy or biomass available for consumption by heterotrophs. Compare gross primary production; secondary production. Productivity: The rate at which plants convert solar energy (sunlight) to biomass. Ecosystems whose plants convert solar energy to biomass rapidly are said to have high productivity. See net primary productivity; gross primary production; net primary production. Net primary productivity: The rate at which net primary production is produced. See productivity; gross primary production; net primary production; secondary production. o Ecosystems interact across landscapes Landscape ecology: The study of how landscape structure affects the abundance, distribution, and interaction of organisms. This approach to the study of organisms and their environments at the landscape scale focuses on broad geographical areas that include multiple ecosystems. Patches: In landscape ecology, spatial areas within a landscape. Depending on a researcher's perspective, patches may consist of habitat for a particular organism, or communities, or ecosystems. An array of patches forms a mosaic. Conversation biologist: A scientific discipline devoted to understanding the factors, forces, and processes that influence the loss, protection, and restoration of biodiversity within and among ecosystems. o Modeling helps ecologists understand systems Model: A simplified representation of a complex natural process, designed by scientists to help understand how the process occurs and to make predictions. Ecological modeling: the practice of constructing and testing models that aim to explain and predict how ecological systems function o Ecosystem services sustain our world Ecosystem services: an essential service an ecosystem provides that supports life and makes economic activity possible. For example, ecosystems naturally purify air and water, cycle nutrients, provide for plants to be pollinated by animals, and receive and recycle waste we generate • Biogeochemical cycles o Nutrients circulate through ecosystems in biogeochemical cycles Nutrient cycles (biogeochemical cycles): The comprehensive set of cyclical pathways by which a given nutrient moves through the environment. o The water cycle affects all other cycles Hydrologic cycle: The flow of water—in liquid, gaseous, and solid forms—through our biotic and abiotic environment. Also called the water cycle. Evaporation: the conversion of a substance from a liquid to a gaseous form Transpiration: the release of water vapor by plants, through their leaves Precipitation: Water that condenses out of the atmosphere and falls to Earth in droplets or crystals. Infiltration: permeation of a liquid into something by filtration Aquifers: a body of permeable rock that can contain or transmit groundwater. Groundwater: water held underground in the soil or in pores and crevices in rock Water table: The upper limit of groundwater held in an aquifer. o The carbon cycle circulates a vital organic nutrient Carbon cycle: A major nutrient cycle consisting of the routes that carbon atoms take through the nested networks of environmental systems. o The nitrogen cycle involves specialized bacteria Nitrogen cycle: A major nutrient cycle consisting of the routes that nitrogen atoms take through the nested networks of environmental systems. Nitrogen fixation: The process by which inert nitrogen gas combines with hydrogen to form ammonium ions (NH4+), which are chemically and biologically active and can be taken up by plants Nitrogen- fixing bacteria: Bacteria that live independently in the soil or water, or those that form mutualistic relationships with many types of plants and provide nutrients to the plants by converting gaseous nitrogen to a usable form Nitrification: The conversion by bacteria of ammonium ions (NH4+) first into nitrite ions (NO2-) and then into nitrate ions (NO3) Denitrifying bacteria: Bacteria that convert the nitrates in soil or water to gaseous nitrogen and release it back into the atmosphere Denitrification: chiefly of bacteria) remove the nitrates or nitrites from (soil, air, or water) by chemical reduction. Industrial fixation: o The phosphorus cycle circulates a limited nutrient Phosphorus cycle: A major nutrient cycle consisting of the routes that phosphorus atoms take through the nested networks of environmental systems. o Tackling nutrient enrichment requires diverse approaches Reducing fertilizer use on farms and lawns and timing its application to reduce water runoff Planting and maintaining vegetation "buffers" around streams to trap nutrient and sediment runoff Using natural and constructed wetlands to filter storm water and farm runoff Improving tech in sewage treatment plants to enhance nitrogen and phosphorus capture Upgrading storm water systems to capture runoff from roads and parking lots Reducing fossil fuel combustion to minimize atmospheric inputs of nitrogen to waterways o A systemic approach to restoration of hope for Chesapeake Bay

Chapter 15

Nonrenewable Energy Sources, Their Impacts, and Energy Conservation Chapter 15 Sources of Energy We rely mostly on fossil fuels Fossil fuels: highly combustible substances formed underground over millions of years from the buried remains of ancient organisms we use three main fossil fuels: coal, oil, and natural gas. Fossil fuels provide most of the energy that we buy, sell, and consume because their high energy content makes them efficient to ship, store, and burn. We use fossil fuels for transportation, heating, and cooking, and also to generate electricity: a secondary form of energy that we can transfer over long distances and apply to many uses Given our accelerating consumption, we risk using up these nonrenewable fuel resources Energy is unevenly distributed Some regions of the globe have substantial reserves of oil, coal, or natural gas, whereas other have very few Consumption rates across the world are also unequal Societies differ in how they use energy It takes energy to make energy Net energy: expresses the difference between energy returned and energy invested Net energy= energy returned-energy invested EROI - energy returned on investment: EROI= energy returned/energy invested Higher EROI ratios mean that we receive more energy from each unit of energy that we invest Fossil fuels are widely used because their EROI ratios have been high Ratios can change Ratios rise as technologies to extract and process fuels become more efficient Ratios fall when resources are depleted and becomes harder to extract Where will we turn for energy? Fossil fuels advanced the standard of living New Ideas Using potent extraction methods such as hydraulic fracturing to free gas and oil tightly bound in rock layers Using powerful new machinery and techniques to squeeze more fuels from sites that were already extracted Drilling deeper underground, further offshore, and into Arctic seabed Pursuing new fossil fuels Better ideas Hasten the development of renewable energy sources Fossil Fuels: Their formation, Extraction, and Use Fossil Fuels are formed from ancient organic matter Fossil fuels form only after organic material is broken down over millions of years in an anaerobic environment: one with little to no oxygen (like the bottoms of lakes, swamps, and shallow seas) The fossil fuels we burn today were formed from the tissues of organisms that lived 100-500 million years ago. Fossil fuels form only under certain conditions, they occur in isolated deposits Geologist searching for fossil fuels drill cores and conduct ground, air, and seismic surveys to map underground rock formations and predict where fossil fuel deposits might occur Fossil Fuels are formed from ancient organic matter (cont.) Coal The most abundant fossil fuel A hard blackish substance formed from organic matter compressed under high pressure, creating dense, solid carbon structures Coal typically results when water is squeezed out of such material as pressure and heat increase over time and when little decomposition takes place strip mining: To extract coal from deposits near the surface, in which heavy machinery scrapes away huge amounts of Earth Subsurface mining: for deposits deep underground. Digging vertical shafts and blasting out networks of horizontal tunnels to follow seams, or layers of coal Mountaintop removal mining: mining coal on immense scales in the Appalachian Mountains, blasting away entire mountaintops Fossil Fuels are formed from ancient organic matter (cont.) Oil and Natural Gas Oil/Crude Oil: The sludge like liquid that contains a mix of various hydrocarbon molecules Natural Gas: a gas consisting of methane (CH4) and lesser, variable, amounts of other volatile hydrocarbons. Petroleum: oil is known by this term Formed from organic materials that drifted down through coastal marine waters millions of years ago and was buried in sediments on the ocean floor. This organic material was transformed by time, heat, and pressure into today's natural gas and crude oil. Two processes give rise to natural gas Biogenic gas: created at shallow depths by the anaerobic decomposition of organic matter by bacteria One source of biogenic natural gas is the decay process in landfills and landfill operators are now capturing this gas to sell as fuel Thermogenic gas: results from compression and heat deep underground. It may form directly or from coal or oil altered by heating Most gas extracted commercially is thermogenic and is found above deposits of oil or seams of coal, so it is often extracted along with those fuels Fossil Fuels are formed from ancient organic matter (cont.) Oil and Natural Gas (cont.) Underground pressure tends to drive oil and natural gas upward through cracks and fissures in porous rock until they become trapped under a dense, impermeable rock layer Oil and gas companies employ geologist to study rock formations to identify promising locations Once such a location is identified, a company conducts exploratory drilling: drilling small holes to great depths. If enough oil or gas is encountered, extraction may begin. Because oil and gas are under pressure while in the ground, they rise to the surface when a deposit is tapped. Once pressure is relieved and some portion has risen to the surface, the remainder will need to be pumped out Fossil Fuels are formed from ancient organic matter (cont.) Unconventional fossil fuels Oil sands Also known as tar sand consist of moist sand and clay containing 1-20% bitumen, a thick and heavy form of petroleum Represent crude oil deposits degraded and chemically altered by water erosion and bacterial decomposition Extracted two ways: For deposits near the surface, a process akin to strip mining for coal or open-pit mining for minerals is used. Fossil Fuels are formed from ancient organic matter (cont.) Unconventional fossil fuels Oil shale Sedimentary rock filled with kerogen (organic matter) that can be processed to produce a liquid form of petroleum Oil shale is formed by the same processes that form crude oil but occurs when kerogen was not buried deeply enough or subjected to enough heat and pressure to form oil Shale Oil: a liquid form of petroleum extracted from deposits of oil shale Methane hydrate/ methane clathrate/methane ice An ice like solid consisting of molecules of methane embedded in a crystal lattice of water molecules Economies determines how much will be extracted Proven recoverable reserve: the amount of a given fossil fuel in a deposit that is technologically and economically feasible to remove under current conditions Refining produces a diversity of fuels Once we extract oil or gas, it must be processed and refined At a refinery, hydrocarbon molecules are separated by size and are chemically transformed to create specialized fuels for heating, cooking, and transportation and to create lubricating oils, asphalts, and the precursors of plastics and other petrochemical products Fossil fuels have many uses Coal Cook, heat, and fire pottery, coal-fired steam engines, generate electricity Natural gas Generate electricity in power plants, to heat and cook Oil Fuel for cars, diesel for trucks, and jet fuel We are depleting fossil fuels reserves reserves-to-production ration (R/P ratio): to estimate how long remaining oil will last Dividing the amount of remaining reserves by the annual rate of production (extraction and processing) Peak oil will pose challenges Hubbert's Peak: The peak in production of crude oil in the US, which occurred in 1970 just as Shell Oil geologist M. King Hubbert has predicted in 1956 Hubbert analyzed data on technology, economics, and geology, and predicated that worldwide oil production would peak in 1995 A divergence of supply and demand could have momentous consequences that profoundly affect our lives Lacking cheap oil with which to transport goods long distances, today's globalized economy would collapse into isolated local economies More optimistic observers argue that as oil supplies dwindle, rising prices will create powerful incentives for businesses, governments, and individuals to conserve energy and to develop alternative energy sources Reaching further for fossil fuels... and coping with the impacts Mountaintop mining extends our reach for coal Mountaintop removal mining has brought coal extraction and its impacts to a whole new level The massive scale of mountaintop removal mining makes it economically efficient The technique can cause staggering volumes of rock and soil to slide downslope, degrading or destroying entire hillsides, polluting or burying streams and disputing life for people nearby Magnifies many of the impacts of traditional strip mining for coal, which unleashes soil erosion and destroys large areas of habitat These mining methods send chemical runoff into waterways in the form of acid drainage, whereby sulfide minerals in newly exposed rock surfaces react with oxygen and rainwater to produce sulfuric acid Secondary extraction produces more fuel Primary extraction: the initial drilling and pumping of oil or gas At a typical oil or gas well, as much as 2/3 of a deposit may remain in the ground Secondary extraction: the extraction of crude oil remaining after primary extraction by using solvents or by flushing underground rocks with water or steam Solvents are injected, underground rocks are flushed with water or steam, or hydraulic fracturing may be used More expensive Directional drilling reaches more fuel with less impact Directional drilling: a drilling technique in which a drill bores down vertically and then bends horizontally in order to follow layered deposits for long distances from the drilling site. This enables us to extract more fossil fuels with less environmental impact at the surface Hydraulic fracturing expands our access to oil and gas For oil and natural gas trapped tightly in shale or other rock, oil and gas companies now use hydraulic fracturing Chemically treated water under high pressure is pumped into layers of rock to crack them and sand or small glass beads holds the cracks open as the water is withdrawn Gas or oil then travels upward through the system of fractures By unlocking formerly inaccessible deposits of shale gas and tight oil, hydrpfracking has ignited a boom in extraction in the US We are drilling farther offshore Geologist estimate that most of the US gas and oil remaining occurs offshore and that deep water sites in the Gulf may hold 59 billion barrels of oil As oil and gas are depleted at shallow-water sites and as drilling technology improves, the industry is moving into deeper and deeper water Deep offshore drilling is boosting oil and gas production, but it poses risks Melting ice is opening up the Arctic As global climate change melts the sea ice that covers the Arctic Ocean, new shipping lanes are opening and nations and companies are jockeying for positon, hoping to stake claim to oil and gas deposits that lie beneath the seafloor Risky We are exploiting new fossil fuel sources such as oil sands Three sources of "unconventional" fossil fuels (oil sands, oil shale, and methane hydrate) are abundant and together could theoretically supply our civilization for centuries However, they are difficult and expensive to extract and process Also their net energy values and EROI ratios are very low Extracting oil sands and oil shale consumes large volumes of water, ruins landscapes, and pollutes waterways Burning these fossil fuels would likely emit more greenhouse gases than our use of coal, oil, and natural gas currently does, worsening air pollution and climate change Emissions pollute air and drive climate change Clean coal technologies aim to reduce air pollution from coal Clean coal technologies: refer to techniques, equipment, and approaches that aim to remove chemical containments during the generation of electricity from coal at power plants. Another approach is to dry coal that has high water content, making it burn cleaner Gasification: coal is converted into a cleaner synthesis gas (syngas) by reacting it with oxygen and steam at a high temperature We gain more power from coal with less pollution Syngas from coal can be used to turn a gas turbine or to heat water to turn a steam turbine Can we capture and store carbon? Carbon capture: technologies or approaches that remove carbon dioxide from power plant or other emissions, in a effort to mitigate global climate change Carbon storage/ carbon sequestration: technologies or approaches to sequester, or store, carbon dioxide from industrial emissions (eg. underground under pressure in locations where it will not seep out) in an effort to mitigate global climate change. The term can also refer to the natural sequestration of carbon by plants through photosynthesis Carbon capture and storage is being attempted at a variety of facilities At the present carbon capture and storage is too unproven to be the central focus of a clean energy strategy We all pay external costs Fossil fuel extraction has mixed consequences for local people Wherever fossil fuels are extracted, people living nearby must weigh the environmental, health, and social drawbacks of extractive development against the financial benefits they may gain Communities where fossil fuels extraction takes place, they experience high-paying jobs and economic activity and for many people these benefits outweigh other concerns Eminent domain: a policy in which a government pay landowners for their land at market rates and the landowners have no recourse to refuse. In eminent domain, court set aside private property rights to make way for projects judged to be for the public good Dependence on foreign energy affects the economies of nations Virtually all of our modern technologies and services depend somehow on fossil fuels We are vulnerable to supplies becoming costly or unavailable Nations with few fossil fuels reserves of their own are especially vulnerable Reliance means that seller nations can control energy prices, forcing buyer nations to pay more as supplies dwindle Energy efficiency and conservation Efficiency and conservation bring benefits Energy efficiency: describes the ability to obtain a given amount of output while using less energy input Energy conservation: describes the practice of reducing wasteful or unnecessary energy use Efficiency results from technological improvements, whereas conservation stems from behavioral choices Greater efficiency allows us to reduce energy use, efficiency is a primary means of conservation Efficiency and conservation help us to waste less and to reduce our environmental impact Extends the lifetime of nonrenewable energy supplies Personal choice and efficient technologies are two ways to conserve We can make conscious choices to reduce our energy consumption by driving less, dialing down thermostats, turning off lights, and cutting back on machinery As a society we can conserve energy by developing technologies and strategies to make devices and processes more efficient One way we can improve the efficiency of power plants is through cogeneration: a practice in which the extra heat generated in the production of electricity is captured and put to use heating workplaces and homes, as well as producing other kinds of power Cogeneration can almost double the efficiency of a power plant Automobile fuel efficiency is a key to conservation A mandate to increase the mile per gallon fuel efficiency of cars Corporate Average Fuel Efficiency (CAFÉ): sets benchmarks for auto manufacturers to meet. The rebound effect cuts into efficiency gains Gains in efficiency from better technology may be partly offset if people engage in more energy-consuming behaviors as a result Rebound effect: the phenomenon by which gains of efficiency from better technology are partly offset when people engage in more energy-consuming behavior as a result. This common psychological effect can hamper conservation and efficiency efforts Driving your fuel efficient car more than what you usually did with your old car Nuclear Power Fission releases nuclear energy in reactors to generate electricity Nuclear Energy: the energy that holds together protons and neutrons in the nucleus of an atom. We harness this energy by converting it to thermal energy inside nuclear reactors: facilities contained within nuclear power plants. This thermal energy is then used to generate electricity by turning turbines with steam Nuclear fission: The reaction that drives the release of nuclear energy inside nuclear reactors; the splitting apart of atomic nuclei In fission, the nuclei of large heavy atoms are bombarded with neutrons Nuclear energy comes from processed and enriched uranium We use the element uranium for nuclear power because its atoms are radioactive, emitting subatomic particles and high-energy radiation as they decay into a series of daughter isotopes Nuclear power delivers clean energy Using fission, nuclear power plants generate electricity without creating the air pollution that fossil fuels do The power-generating process is essentially emission-free Advantages Nuclear power poses far fewer chronic health risks from pollutants Generates far more power than coals Disadvantages Arranging the safe disposal of radioactive waste is challenging If an accident occurs at a power plant, the consequences can potentially be catastrophic Nuclear power poses small risks of large accidents Three Mile Island A combo of mechianical failure and human error caused coolant water to drain from the reacter vessel, temperatures to rise inside the reactors core Chernobyl Fukushima Daiichi Waste disposal remains a challenge Nuclear power's growth has slowed homework The United States and other industrialized nations devote the greatest proportion of their oil use to __________. Transportation What is the difference between EROI (energy returned on investment) and net energy? Net energy is simply the difference between energy returned and energy invested. EROI is a ratio with energy return in the numerator and energy invested in the denominator. Which of the fossil fuels is most abundant on Earth? Coal The process of __________ turns crude oil into the type of gases that can be used for cooking, in cars, and for other human purposes. Redefining Plant-based organic matter that is compressed under high pressure to form solid carbon structures is known as __________. coal What is Hubbert's peak? a prediction, based on rates of extraction and new discovery, of when a country's or global oil production will be at a maximum and then start to fall Which fossil fuel is produced as a by-product that occurs when bacteria decompose organic material under anaerobic conditions? Methane Many pollutants from coal-fired power plants are properly managed today. Which of the following is currently considered to be the biggest threat to the environment? Carbon dioxide All fossil fuels, including coal, are considered an indirect form of ____________ energy. Solar Where is electricity made at a coal-fired power plant? generator During peak usage, what happens to the cost of electricity? It almost always increases What color smoke coming from a coal-fired power plant would indicate wasted fuel? black Which of the following countries exports the most oil to the United States? Canada What compound that results from hydraulic fracturing gives rise to air pollution? Methane How is the energy produced by nuclear fission used to produce electricity? Water in the containment vessel is kept under high pressure and heat from the fission reactions that heat it to well over boiling. This is then used to boil another loop of water, which turns a turbine that drives a generator and makes electricity. Which of the following is one of the biggest problems with nuclear power? Radioactive waste Which of the following statements accurately describes nuclear fusion reactors? Fusion reactions require very high temperatures Which of the following individuals is most likely to support fracking? An executive for the Western States Petroleum Association. In California, why do most energy companies choose to use fresh water for fracking as opposed to brackish water? Fresh water is typically cheaper Your aunt worked diligently to help get the most stringent laws against fracking passed in her state. Where does she live? Vermont You are a mechanical engineer for C & J Energy Services, working on an idea to safely frack the Monterey Shale. What is the biggest obstacle for you to overcome? The geology of the region You are an environmental activist in Texas and wish to promote an anti-fracking bill. You decide to use the same unique focus as that being used in California. What are you focusing on? The intense use of water

Chapter 6

Human Population How population size, affluence, and technology determine human impact on the environment Figure 6.2 Labeled Human Population Growth SE 6-4 Human population growth Is growth really a problem? NO People can find or manufacture additional resources to keep pace with population growth. Nations become stronger as their populations grow. YES Not all resources can be replaced. Even if they could, quality of life suffers. Nations do not become stronger as their populations grow. SE 6-4 Human population growth SE 6-4 Human population growth SE 6-4 Human population growth Technology can change K What is the Human K Estimates from 2 billion to 1 trillion high estimate assumes living in floating cities and huge advances in technology K depends on standard of living At N = 1 trillion everyone gets 100 sq. meters and 1500 calories per day 'Little r' Exponential growth is described by the equation Nt = N0ert 'r' is the natural rate of population change due to birth ('b') and death ('d') rates per capita (excludes immigration and emigration) units of % per year. Population Growth Rates, 2013 Projected Human N Activity Divide into groups and calculate these two projected values: doubling time of the human population N of humans in 2050 (in 42 years) Nt = N0ert r= 0.75 r=.0075 T=33 yrs No= 7.5 billion Nt= (7.5)e^(.0075x33)= 9.6 billion TFR strongly influences 'r' Total fertility rate (TFR) = average number of children born per woman during her lifetime Replacement fertility = the TFR that keeps population size stable For humans, replacement fertility is about 2.1 Why not 1.0? 2.0? Total fertility rates Demography is the study of human population The study of population size, density, distribution, age structure, sex ratio, and rates of birth, death, immigration, and emigration of people. Age structure diagrams (often called population pyramids) are visual tools scientist use to illustrate age structure Demographic transition theory Demographic transition = model of economic and cultural change Explains pattern observed in Western nations as they became industrialized declining death rates, declining birth rates, and rising life expectancies SE 6-12 Demographic transition SE 6-12 Demographic transition SE 6-12 Demographic transition SE 6-12 Demographic transition Demographic transition theory Pre-industrial stage: high death rates and high birth rates. Transitional stage: death rates fall due to rising food production and better medical care Industrial stage: birth rates fall, as women are employed and as children become less economically useful in an urban setting. Post-industrial stage: birth and death rates remain low and stable The "IPAT" model Shows how Population, Affluence, and Technology interact to create Impact on our environment. I = P A T Revisit your global footprint... Go to www.footprintnetwork.org Calculate your 'global footprint' based on your lifestyle as before... Now recalculate assuming the density of your living conditions has doubled. Is this better? Yes or no, and why, by next class session... Global Ecological Footprint Zero Population Growth (ZPG) Should we set ZPG as a goal for humans? Can be attained by adjustments in either birth or death rates... ...and we might not like the environmental conditions leading to high death rates? If so, how do we accomplish this? Views on population control Discussion Time! The best way to reduce growth rate for the human population is Free access to condoms for males and females Free access to birth-control pills for females Free access to abortion Increased access to education for females Prohibition of pre- and perinatal healthcare A strict one-child policy, such as that enacted in the People's Republic of China A laissez-faire approach, since nature is ultimately self-correcting HIV and population growth Southern Africa Infects 1 in 5 kills babies born to infected moms orphaned over 14 million children cut 19 yr from life expectancies HIV and population growth Female literacy and TFR Poverty and TFR Family planning & contraception Family planning is a key approach for controlling population growth Family planning the effort plan the number and spacing of one's children. Birth control the effort to control the number of children one bears, particularly by reducing the frequency of pregnancy Contraception the deliberate attempt to prevent pregnancy despite sexual intercourse Reproductive window the period of a woman's life beginning with sexual maturity and ending with menopause, in which she may become pregnant. Woman can have 25 children within that window TFR in Bangledesh What role should the U.S. play? Funds to support UN programs for family planning has been appropriated by Congress annually for > 20 years Is this appropriate? Views vary... http://www.unfpa.org/public/News/pid/1562 Inequality in future growth Demographic fatigue ='failed states'? Many governments of developing countries are experiencing demographic fatigue unable to meet the social, economic, and environmental challenges driven by rapid population growth Can lead to failed states = social and political chaos that can expand regionally This raises the question: Will today's developing countries successfully pass through the demographic transition? Affluence and the environment Poverty can lead to environmental degradation... BUT wealth and resource consumption can produce even more severe and far-reaching environmental impacts. Key Points The human population is larger than at any time in the past. 90% of children born today are likely to live in conditions far less healthy and prosperous than those in the industrialized world. The rate of growth has decreased nearly everywhere, and some countries are seeing population declines. Most developed nations are through the demographic transition and could transition to ecologically sustainable economies. Key Points (cont.) Many developing nations are making their way through the demographic transition, and equitable treatment is vital to their success. Women's rights are expanding worldwide, which helps slow population growth. Contraception is an important tool to reduce TFR Sustainability demands that we stabilize our population size as part of a sustainable future, a critical insight of I = PAT.

Chapter 1

• Our Island, Earth o Our Environment surrounds us Environment: The sum total of our surroundings, including all of the living things and nonliving things with which we interact. o Environmental science explores our interactions with the world Environmental science: the scientific study of how the natural works, how our environment affects us, and how we affect our environment. o We rely on natural resources Natural resources: the substances and energy sources we take from our environment and that we rely on to survive. Renewable natural resources: natural resources that are replenished over short periods of time. Nonrenewable natural resources: natural resources that have a finite supply and are formed far more slowly than we use them. Once depleted nonrenewable resources is no longer available Ecosystem services: an essential service and ecosystem provides that supports life and makes economic activity possible. • For example, ecosystem naturally purify air and water, cycle nutrients, provide for plants to be pollinated by animals, and received and recycle the waste o Population growth amplifies our impact Agricultural revolution: people began to grow crops, domesticate animals, and live sedentary lives on farms and in villages, they produced more food to meet their nutritional needs and began having more children Industrial revolution: a shift from rural life, animal powered agriculture, and handcrafted goods toward an urban society provisioned by mass production of factory-made goods and powered by fossil fuels Fossil fuels: nonrenewable energy sources such as coal, oil, and natural gas o Resource consumption exerts social and environmental pressures Ecological footprint: expresses the cumulative area of biologically productive land and water required to provide the resources a person or population consumes and to dispose of or recycle the waste the person or population produces Overshoot: the amount by which humanity's resource use, as measured by its ecological footprint, has surpassed Earth's long-term capacity to support us o Environmental science can help us avoid past mistakes • The Nature of Environmental Science o Environmental science is interdisciplinary Interdisciplinary: bringing techniques, perspectives, and research results from multiple disciplines together into a broad synthesis Natural sciences: disciplines that examine the natural world Social sciences: disciplines that address human interactions and institutions Environmental studies: an academic environmental science program that emphasizes the social sciences as well as the natural sciences o Environmental science is not the same as environmentalism Environmentalism: the social movement dedicated to protecting the natural world- and, by extension, people from undesirable changes brought about by human actions • The Nature of Science Science: systematic process for learning about the world and testing our understanding of it o Scientists test ideas by critically examining evidence Observational science/ descriptive science: research in which scientists gather basic info about organisms, materials, systems, or processes that are not yet well known Hypothesis-driven science: research that proceeds in a more targeted and structured manner, using experiments to test hypotheses within a framework traditionally known scientific method o The scientific method is a traditional approach to research Scientific method: a technique for testing ideas with observations • Make observations • Ask questions • Develop a hypothesis o Hypothesis: a statement that attempts to explain a phenomenon or answer a scientific question • Make predictions o Prediction: specific statements that can be directly and unequivocally tested • Test the prediction o Experiment: an activity designed to test the validity of a prediction or a hypothesis o Variables: conditions that can change o Independent variable: a variable the scientist manipulates o Dependent variable: the variable that is affected by manipulation of the independent variable in an experiment o Controlled experiment: an experiment in which a treatment is compared against a control in order to test the effect of a variable o Control: the portion of an experiment in which a variable has been left unmanipulated, to serve as a point of comparison with the treatment o Treatment: the portion of an experiment in which a variable has been manipulated in order to test its effects. Compare control. • Analyze and interpret results o Data: information, generally quantitative information o We test hypotheses in different ways Correlation: a statistical association among variables o The scientific process continues beyond the scientific method Peer Review • Peer Review: the process by which a manuscript submitted for publication in an academic journal is examined by specialists in the field, who provide comments and criticism (generally anonymously) judge whether the work merits publication in the journal. Conference presentations Grants and funding Repeatability Theories • Theories: a widely accepted, well-tested explanation of one or more cause-and-effect relationships that has been extensively validated by a great amount of research o Science undergoes paradigm shifts Paradigm: A dominant philosophical and theoretical framework within a scientific discipline. • Environmental Ethics Ethics: The academic study of good and bad, right and wrong. The term can also refer to a person's or group's set of moral principles or values. Relativists: An ethicist who maintains that ethics do and should vary with social context. Compare universalist. Universalists: An ethicist who maintains that there exist objective notions of right and wrong that hold across cultures and situations. Compare relativist. Ethical standards: A criterion that helps differentiate right from wrong. o Environmental ethics pertains to people and the environment Anthropocentrism: A human-centered view of our relationship with the environment. Compare biocentrism and ecocentrism. Biocentrism: A philosophy that ascribes relative values to actions, entities, or properties on the basis of their effects on all living things or on the integrity of the biotic realm in general. The biocentrist evaluates an action in terms of its overall impact on living things, including—but not exclusively focusing on—human beings. Compare anthropocentrism and ecocentrism. Ecocentrism: A philosophy that considers actions in terms of their damage or benefit to the integrity of whole ecological systems, including both living and nonliving elements. For an ecocentrist, the well-being of an individual is less important than the long-term well-being of a larger integrated ecological system. Compare anthropocentrism and biocentrism. o Conservation and preservation arose with 20th century John Muir: Scottish immigrant to the United States who eventually settled in California and made the Yosemite Valley his wilderness home. Today, he is most strongly associated with the preservation ethic. He argued that nature deserved protection for its own inherent values but also claimed that nature facilitated human happiness and fulfillment. Gifford Pinchot: The first professionally trained American forester, Pinchot helped establish the U.S. Forest Service. Today, he is the person most closely associated with the conservation ethic. Conservation ethic: An ethic holding that people should put natural resources to use but also have a responsibility to manage them wisely. Compare preservation ethic. o Aldo Leopold's land ethic inspires many people Aldo Leopold: American scientist, scholar, philosopher, and author. His book The Land Ethic argued that humans should view themselves and the land itself as members of the same community and that humans are obligated to treat the land ethically. o Environmental justice seeks fair treatment for all people Environmental justice: The fair and equitable treatment of all people with respect to environmental policy and practice, regardless of their income, race, or ethnicity. Responds to the perception that minorities and the poor suffer more pollution than whites and the rich. • Sustainability and Our future Sustainability: A guiding principle of environmental science, entailing conserving resources, maintaining functional ecological systems, and developing long-term solutions, such that Earth can sustain our civilization and all life for the future, allowing our descendants to live at least as well as we have lived. Natural capital: Earth's accumulated wealth of resources. o Population and consumption drive environmental impact o Energy choices will shape our future o Sustainable solutions abound Sustainable development: development that satisfies our current needs without compromising the future availability of natural capital or our future quality life o Student are promoting solutions on campus Campus sustainability: A term encompassing a wide variety of efforts by students, faculty, staff, and administrators of colleges and universities to make campus operations more sustainable. Includes efforts toward energy efficiency, water efficiency, emission reductions, transportation improvements, sustainable dining, landscaping improvements, renewable energy, curricular changes, and more.