Ch 18
Earth is experience radiative forcing of 1.6 watts/m2 of thermal energy above what is was experiencing 250 years ago.
Radiative forcing us the amount of charge in thermal energy that the factor causes (positive=warming and negative=cooling). Scientists have found that Earth has received radiative force if 1.6watts/m^2, meaning that today's planet is retaining 1.6watts/m^2 more thermal energy that it is emitting into space. This can eventually lead to the alteration of climate.
Changes in precipitation have varied by region.
A warmer atmosphere speeds evaporation and hold more water vapor, thus precipitation has increased by 2% (some regions are receiving more rain/snow-Iowa along the Mississippi whereas some are receiving less-Southwestern US). It is predicted that religions will vary in ways of parallel regions differences will be the same in the last century with rainy areas getting ranker and dry areas getting drier. These events are tied to Hadley Cells in the atmosphere.
Earth's climate changes naturally over time, but it is now changing rapidly because of human influence.
Climate is an area's long term atmospheric conditions; temperature, precipitation, wind, humidity, barometric pressure, solar radiation, and other characteristics. Global warming is the increase in Earth's average surface temperature, which drives other component of climate change. Climate change is largely effected by fossil fuel combustion and deforestation..
Climate models serve to predict future changes in climate.
Climate models are programs that combine what is known about atmospheric circulation, ocean circulation, atmosphere-ocean interactions, and feedback cycles to simulate climate processes (not possible without computers to make complex math equations). They provide starting information to the model and set up the rules for the simulation in order for it to run, they test for efficacy by entering past to present climate data, so that we can assume that it can accurately predict the future. As technology improves, these predictions will become more accurate (though it will not always consider factors that are unknown).
A carbon tax, specifically a fee and dividend approach, is another option.
Critics of cap-and-trade programcs prefer that the giver ember enacts a carbon tax u. Which polluters are charged a fee for each unit of greenhouse gases they emit (gives a financial incentive to do so). This tax can be implemented by charging energy producers, utilities, or motor vehicle users which would be scaled by energy efficiency. Though carbon taxing of industry would cause a rise in charging of consumers, thus the fee and dividend approach has been taken which funds from the car in tax paid to the government by polluters are transferred as a tax refund to taxpayers (this reimbursed consumers if prices rise.
By burning fossil fuels and clearing forests, people are increasing atmospheric concentrations of greenhouse gasses.
Fossil fuels from the ground are burned in homes/factories/automobiles which transfer from underground reservoirs to the atmosphere (why CO2 emissions have increased dramatically). In forests, plants are able to capture CO2, though deforestation of these plants has led to influx of it into the atmosphere and reservoirs on Earth's surface. Methane from by using fossil fuels to raise livestock creates organic matter in landfills as a waste product which methane is emitted from.
Increased greenhouse gas emissions enhance the greenhouse effect.
Greenhouse gases naturally exist in the world, without them the world would be too cold to support life on Earth. Though human made greenhouse gasses are becoming more concentrated, so much that our own species has not experienced such change in the past 250 years as CO2 emissions has reached a level of 396ppm, highest in the last 20 million years.
Ocean acidification may be one of the most far-reaching impacts of our greenhouse gas emissions.
Ocean acidification is a result of increased CO2 emissions getting into the ocean water which leads to the creation of carbonic acid which eats away at coral reefs, mangrove forests, salt marshes which all protect the coasts. Organisms are also unable to build exoskeletons that helps protect themselves. Coral reefs especially for Maldives residents as it provides a habitat for fish that are eaten by people, protects from coastline erosion, and offers as a tourism site. As the pan of the ocean continues to decline, in the next 100 years coral reefs will disappear and marine biodiversity/fisheries will suffer.
Sea level has risen an average of 21cm (8.3 in) over the past 130 years, and will rise by more in the coming century.
Runoff from melting glaciers and ice sheets are causing sea levels to rise, and the warming of ocean water is expanding in volume, this rise can cause coastlines to have parts of their land underwater. Causing beach erosion, coastal flooding, saltwater invading aquifers,. And greater impact from storm surges (temporary localized rise in sea level that brings in high tide with winds associated with storms).
Greenhouse gases such as carbon dioxide, methane, water vapor, nitrous oxide, ozone, and halocarbons warm the atmosphere by absorbing and re-emitting infrared radiation.
The Earth's surface naturally absorbs solar radiation, increasing in temperature and emitting infrared radiation. Greenhouse gasses may absorb this infrared radiation and re-emit it, making some of it travel back to the troposphere and Earth's surface (greenhouse effect). CO2 is not as strong as NO/methane but is more abundant due to human activity and longer residence time.
The sun provides most of Earth's energy. Earth absorbs 70% of incoming solar radiation and reflects 30% of back into space.
The sun(keeps us warm and have light), atmosphere (keeps us warmer than 59*F), and its oceans (store and transport moisture/heat) are the Earth's influences in climate. The absorption of sun allows for evaporation/photosynthesis/winds. The greenhouse effect causes warming to occur (in which long wavelength from the gasses that have re-emitted the radiation) to warm Earth's surface and lower atmosphere.
Temperatures in Earth have warned by an average of 0.74*C (1.33*F) over the last century and are predicted to rise 1.8-4*C (3.2-7.2*F) over the next century.
The surface temperature of Earth has risen by 1.6*F in the last 100 years, increasing air temperature over land and sea surface. This has been increasingly noticeable since 1975 with having very hot days and heatwave frequency growing around the world and lessening of cold days. From 2001-2010 was the hottest ever recorded decade in the past 150 years (when measurements began), since 1960s each decade has been increasingly warm. Most areas in the U.S has experienced temperature increase of more than 1*F from 1991 to 2011. In the next 2 decades we are expected to have a temperature rise of 0.7*F (with the halt of greenhouse gas emissions), and by the end of the 21st century global temperatures will be 3.2-7.2*F higher than now, thus hot days/heatwaves will become more frequent, with polar regions experiencing the most intense warming.
Direct measurements of temperature, precipitation, and other conditions us about current climate.
With use of many technologies (temperature/thermometers, rainfall/rain gauges, wind speed/anemometers, air pressure/barometers) paired with computer programs we are able to document and understand fluctuations of weather at all times in every region. These variables of climate and precipitation can also be measured in other ways; records of economic activity that are affected by the climate like fishers encountering ice formation and winemakers recording the length of growing season Measuring the chemistry of the atmosphere and oceans can tell us the pollutants are present.
Addressing climate change will require multiple strategies.
Advances in agriculture (methane from rice cultivation and manure from feedlots, nitrogen filled fertilizer, use of biofuel crops), forestry (preserving forests, reforesting cleared areas, sustainable forestry practices), and waste management (treat waste water, recover methane from landfills, encouraging recycling/composting, reuse of materials/products) are all ways that can help us mitigate the climate change. Though it takes all sectors of are economy to make it possible.
Input it aerosols into the atmosphere exerts a variable but slight cooling effect.
Aerosols are microscopic droplets and particles that have a cooling/heating effect on the atmosphere.. Soot particles generally warm the atmosphere by absorbing solar radiation, but most tropospheric aerosols cool it by referring sun rays (volcanic eruptions, Mount Pinatubo Philippines)
International efforts to design a treaty to follow the Kyoto Protocol have made some prepared, but have fallen far short of what is needed to limit climate change.
At the end of Copenhagen Accord of 2009, nations were left without specific targets or would commitments as leaders of major nations couldn't make an agreement. Major nations like China/India/U.S continue to be top emitters and not agree to a roadmap that leads to greater reduction. Nations continue to face the daunting challenge in treaty process agreement and creation.
New automotive technologies and investment in public transportation will help reduce emissions.
Automotive Technology- Cars with mote aerodynamic design, increased engine efficiency, and improved tire design can help make them more fuel efficient as over 85% gas can only help fuel the car (no extra uses). The demand for more fuel effected cars have increased. This has also lead to the development of hybrid cars (combination of electric motors with a gasoline powered engine), full ev's, alternative fuels, compressed natural gas, biodiesel, and hydrogen fuel cells as alternatives for automobiles. Transportation Choices- We can make a change to our lifestyles like living closer to workplaces or use mass transit (only serves 3-4% of passenger trips already reduces gasoline use by 4.2bil gallons and 37mil metric tons of CO2 emissions. This would cut its air pollution, dependence on imported oil, and contribution to climate change, though the U.S has not developed convenient public transportation.
Individuals and corporations are increasingly exploring carbon offsets and other means of reducing personal carbon footprints.
Carbon offsets are voluntary payments intended to enable another entity to help reduce the emissions that one is unable to reduce (coal power plant funds reforestation project to help soak in CO2), the goal of this is to reach carbon neutrality (no net carbon is emitted). Though they offsets are only effective if they fund emissions reductions that would not occur otherwise. Businesses/corporations can find ways to reduce their carbon footprints (Pearson Education in 2009 reduced energy consumption and carbon footprint by upgrading buildings for energy efficiency, designing more efficient computer servers, reducing the number of vehicles in its west, increasing the proportion of hybrid vehicles, and cutting back on employee business travel while enhancing the use of video calls. Another 47% was eliminated by purchasing clean renewable energy by installing solar panel arrays in its 2 sites in New Jersey and installing a wind turbine in a Minnesota Site, they also fund numerous programs to preserve forests to pay forward the 41% offset.) We can also reduce our carbon footprint by choosing energy efficient appliances in our homes, turning off lights, eating less meat, deciding where we live and how we get to work. College students through lobbying and activism have successfully brought attention of the people about the importance of climate change.
Melting glaciers will diminish water supplies, and melting ice sheets are adding to sea level rise.
Climate change has caused glaciers to melt away a significant amount of its mass and are expected to disappear by 2030. Snow on mountain tops melt in water and supplies people with it, warming temperatures will force these people to get their water from somewhere else. Ice sheets in the Arctic are melting at a rapid rate due to warmer ocean waters, ice shelves are disintegrating (precipitation is giving Antarctic snow to thicken the interior, but the edges are decreasing). This is because as snow/ice melts, a darker surface is revealed and is unable to reflect as much light, thus the surface warms causing it to melt more and absorption of radiation becomes greater. It is expected to continue in areas of the poles, developed nations (U.S., Canada, Russia) have made its way through these new passageways to exploit underwater oil and mineral reserves and claiming them as their own. The melting of permanently frozen ground (permafrost) to thaw, this loosens up the soil and infrastructure/buildings that use it as a foundation become destabilized. Permafrost can also release Meghan gas that had been stored over time, this can intensify climate change.
Climate change exerts impacts on organisms and ecosystems, as well as in agriculture m, forestry, health, and economics.
Climate change has caused organisms that have been adjusted to their environment to readjust to meet their biological needs which are regulated by temperature; plants leaf early, insects hatch early, birds migrate early, animals breed early (the great tits bird cannot successfully grow their population because caterpillars are hatching sooner than what they are used too). It also causing a shift in which plant and animal populations are are moving towards the poles, since some of these species haven't evolved to different climates along their journey, they are threatened with extinction (forced to adapt to mountains and go uphill, but may not survive). With plants not being able to grow due to climate change, CO2 emissions will not be mitigated and erosion/flooding will occur more often (which can pollute and alter aquatic systems and areas of bodies of water will have decreased precipitation). Agriculture- In temperate zones, increased temperatures extends growing season and the addition of more available CO2 allows for increased yields with photosynthesis occurring more, though these crops have become less nutritious. Rainfall shifts in space and time could also cut productivity as floods and droughts move. Due to the 5.4*F increase, (sub) tropical regions will experience a decline in crop yield as growing and harvest seasons will be decreased by drought. Forestry- Trees in forests may experience more growth due to the abundance of CO2 in the atmosphere, but droughts, fires, disease will occur more often, thus these gains will be lost (El Niño 1997-1998 destroying Indonesia/Mexico/Brazil, fired made invasive species of bark beetles to migrate and destroy forests in NA) Health- Heat waves will be more abundant, causing heat stress which can cause death (1995 Chicago killed 485, and 2003 Europe killed 35,000). Respiratory ailments may come as a result of air pollution and hotter weather allowing photochemical smog to form. Tropical diseases may spread far away as they move towards the poles. Flooding being more frequent can cause disease and sanitation problems, as well as injuries and drowning during floods. Economics- it is expected that climate change will result in a net loss, and that the gap between rich and poor will widen. The poor will lack wealth and technology in order to adapt to the climate change and will have to rely on resources that are sensitive to climatic condition. Damage from climate change will cause the GDP grossing to go down by 1-5%, but by spending money on mitigating climate change can help reduce the damage in the future.
Conservation, energy efficiency, and new clean and renewable energy sources will help reduce greenhouse gas emissions.
Conservation and Efficiency- We can replace light bulbs with compact fluorescent lights to reduce energy use by 40%, replacing old washing machines cut CO2 emissions by 440llb, and change heating/cooling systems to reduce energy use/emissions by 30%, which also reduces utility bills. For industry, they can use cogeneration to produce fewer emissions per unit of energy generated. Source of Electricity- Replacement for fossil fuels like nuclear power, bio energy, hydroelectric power, geothermal power, solar photovoltaic cells, wind power, and ocean sources can help reduce emissions as they create no additional gasses (some may produced the making of infrastructure)- carbon capture and plan to store it underground
Some scientists are so anxious about our lack of response to climate change than they are now studying potential geo-engineering options.
Due to the reluctancy of governments and society to make a change to help mitigate global warming, scientists have taken a geo-engineering approach to reverse global warming; creating artificial trees to suck CO2 out of the air, blocking sunlight before it reaches Earth to cool the planet (doesn't stop acidification from happening). Though these ideas would take years to develop and have unforeseen risks in the environment, politicians may lose incentive to develop policy on reducing emissions.
Climate change and its impacts vary regionally. (Map Page 505)
In the Arctic, the melting and thinning of ice sheets/sea ice has caused people and wildlife trouble traveling and hunting in these areas, in recent years with greater death rate due to starvation and exhaustion. Permafrost and rising sea levels can cause destabilizing of buildings who already face increased storm frequencies. In the U.S, states nationwide will experience a 1.5*F increase, which will make extreme weather events occur more frequently and costly and is expected to worsen (farmers, city dwellers, costal communities, tax payers will have escalated costs). Winter/Spring precept will decrease in the south and increase in the North, droughts and floods will spawn in different areas(water shortages), rising sea levels would effect the West/East/Gulf Coasts, Storm surges will continue to destroy land/property, fires/pest outbreaks will spread to alter forests, marine ecosystems/fisheries will suffer ocean acidification, health problems can arise in humans/organisms, and permafrost undermine buildings/roads.
Some U.S states and cities are acting to address emissions.
Mayors from over 1000 cities from all states have signed on the U.S Mayors Climate Protection Agreement, where mayors are committed to their to cities to pursue policies to "meet or beat" Kyoto Protocol guidelines. States have enacted mandates for renewable energy production by seeking to boost cleaner alternatives to fossil fuels and adopting plans for adapting to climate change's impacts (Bloomberg in 2008 launched the New York City Panel on Climate Change in part of PlaNYC sustainability plan to prepared for the 2010 Superstorm Sandy, California passed Global Warming Solutions Act to cut emissions by 25% by 2020 followed by a mandate for higher fuel efficient automobiles, Northeastern states run a joint cap-and-trade program from carbon emission from power plants).
Milankovitch cycles, solar radiation, ocean absorption, and ocean circulation all influence climate.
Milankovitch cycles- describes as the 3 types of periodic changes in Earth's rotation and orbit around the sun (tilt on axis, change in orbit shape, and how much it wobbles in its axis). This alters the way solar radiation is distributed over Earth's surface, thus triggering long term climate variation (glaciations=drop in temps/interglacial=rise in temps, both occur at the poles) Solar output- the varying if the amount of Rashid the sun emits over time. These variations over time hasn't proven that it drives significant temperature change in Earth's surface. It's hard to tell nowadays as the solar output is low and that solar radiation has been decreasing. Ocean absorption- hold 50 times s'more carbon than the atmosphere, when CO2 is dissolved into water Maine phytoplankton are able to use it for photosynthesis. Though oceans now are absorbing less, thus more is being added to the atmosphere (only slows globally warming, not prevent it). This Gallas uhh because waters are warmer now and are unable to absorb as much CO2 as before (creates a positive feedback loop) Ocean circulation- ocean wanted exchange heat with the atmosphere to and is moved by ocean currents, mostly occurring around the equator. This has influenced regional effects such as the studying of fresh water from Greenland to discover effects. Ocean circulation is factor of the systematic shift in the ocean (El Niño and La Niña often leave areas with rainstorms and floods in dry areas and droit's/fires in moist areas (this effects wildlife/agriculture/fisheries.
Both adaptations and mitigation are necessary.
Mitigation is the sun to lessen the severity of climate change by switching to clean/renewable energy source, preventing deforestation, improving energy efficiency, recovering landfill gas, and encourage sustainable farm practices. Adaptation is the strategy to cushion ourselves from the impacts of climate change (Malé city wall, Tuvalu people migrating) through restricting coastal development, adjusting farm practices (cope with drought) and modifying water management practices (reduce river flows, glacial floods, contamination of groundwater). These strategies put a halt to emissions and make it easier for us to adjust to the natural occurring part of climate change.
Proxy indicators-such as data from ice cores, sediment cores, tree rings, packrat middens, and coral reefs-reveal information about past climate.
Paleoclimate is climate of the ancient past that gives us a base like to measure the changes in our climate today, proxy indicators are used as N indirect evidence that serves as a substitute for direct measurement of the past. By extracting ice cores from mountain tops (layers of snow compressed over time) we can observe the chemistry ice and the bubbles in each layer to determine atmospheric composition, greenhouse gas concentrations, temperature trends, snowfall, solar activity, and frequency of forest fires/volcanic eruptions. Drilling up sediments under bodies of water (Easter Island) can preserve pollen grains and plant remnants, knowing what plants that used to be there can tell us about the climate of the region at that place/time. Tree rings (bristle pines)tell us how much a tree has grown in a particular season (wild rings indicate wetter seasons, charred rings indicate that a fire took place that year). Packrat Middens are rodents that carry seeds and plant parts back to dens away from the rain in arid regions (this these parts maybe preserved in the rock crevices and caves). Coral reefs are able toy trace isotope ratios from ocean water as they grow, incorporating them into the structure and is visible by showing growth bands in layers.
Emissions trading programs provide a way to harness the free market and engage industry in reducing emissions.
Regional Greenhouse Gas Initiative: 1. Each state decides what polluting source is required to participate 2. Each stage sets a cap on the total CO2 emission it would allow 3. Each state distributes to each emission site (one permit per ton up until cap) 4. Each state will lower its cap progressively 5. Sources with too few permits must buy permits from other sources or pay with credits (sources with too many may sell permits) 6. Any source emitting more than it's permitted amount faces penalties. The European Union Emission Trading Scheme is the largest cap-and-trade program that started in 2005, but permits began to lose value as emission reduction declined. So for this to not happen the government must put policies in place to limit emission.
The Kyoto Protocol provided a first step for nations to begin addressing climate change.
The 1997 Kyoto Protocol (made by the FCCC to tackle climate change) mandated signatory nations to reduce emissions of six greenhouse gasses to levels below those of 1990 by 2008-2012, it would take effect in 2005 after Russia joined the 126 nations in ratifying the plan. The U.S was the only developed nation to not ratify it because leaders believe that it was unfair as developed nations were forced to reduce more emission than rapidly developing ones (China/India). The proponents argued that the difference in requirements was due to industrialized nations creating the problem, thus they must lead in resolving it. By 2010, emissions reduced by 8.9% from 1990 levels (largely due to Soviet reduction in their economy), though not accounting for this factor emissions increased by 4.9% due to India/China/U.S not reducing their own emissions, but increasing them.
Climate science is a huge body of research. The Intergovernmental Panel on Climate Change (IPCC) synthesizes current research, and it's periodic reports represent the consensus of the scientific community.
The IPCC published periodic assessments of climate change's impacts on the world (east 1988 by UNEL and WMO, won Novel Peace Prize in 2007). This panel has hundreds of scientists and government representatives. In 2007, the IPCC's repost summarized thousands of scientific studies and observed trends in surface temperature, precipitation patterns, snow/ice cover, sea levels, storm intensity, and other factors (and predicting effects of greenhouse gas emissions), this addressed impacts of current/future climate change in wildlife, ecosystems, and society as well as ways to respond to it (conclusions need to be approved by governments as impacts are conservative).
Developing renewable energy technologies presents economic opportunities.
The U.S (India and China under the same assumption) fear to reduce emissions as they believe that it will come at the cost of economic loss because resource use per capita is so high that reduction would make them lose more. Though Germany and U.K have successfully reduced greenhouse gas emissions by 25 and 23% all while having highly successful economies, and these citizens enjoy living standards similar to those in the U.S with far less emissions. Developed nations are actually in the best position to experience economic growth because they are best positioned to invent, develop, and market new technologies to power their nations. Germany/Japan/China have worked towards the production, deployment; and sales of solar energy technology, especially with China embarking on several initiatives to develop and sell renewable energy technologies more advanced than any in the world, with the U.S not acting quick in the same pursuit.
Extreme weather events are becoming more frequent, likely in part as a result of modification of the jet stream.
The US in 2012 had 34,000 daily high records and 6700 daily low records, suffered droughts that 3/5 of the country's agriculture failed and Hurricane Sandy caused over $60 bil in damages. Insurers have also noticed the more frequent events as they found themselves paying more money to people each time of an event with a 5 times increase in NA. Jennifer Francis or Rutgers U and Stephen Vavrus of U of Wisconsin discovered that the warming of the Arctic has been greater than at lower altitudes, which has weakened the polar jet stream (high altitude air current that blows from west to east and meanders north and south) which influences weather on a daily basis in NA and Eurasia. The slowing down of this current may get stuck in the north-south orientation, making the current that is going west-east stay in areas for a long period of time, this is called the atmospheric blocking pattern (rain in a city lasts longer than usual). This block has caused the 2011 drought in Texas, 2012 wildfires in Colorado, and both floods/heatwaves in Europe.
Storm surges worsened by higher sea level threaten the mainland U.S., and not just oceanic islands.
The higher the sea level, the further the storm surge can reach (Maldives capital Malé was struck by a tsunami in 1987 that had increased damage due to higher sea levels, people died and the economy suffered-island)Hurricane Sandy devastated the east by damaging infrastructure and property, which put a halt to economic activity (was strengthened by warmer water and higher sea levels). Hurricane Katrina in 2005 demolished the Gulf Coast and New Orleans because human activity had damaged the costal wetlands which help protect from natural disturbances. With 53% of the U.S population living in costal communities (Tampa, Miami, New Orleans) have greater vulnerability to impacts of storm surges as Greenland's ice melts to raise the sea levels and could lose up to 9% if their land area. Saltwater would contaminate aquifers and soil that they depend on. Communities along low lying river deltas such as Bangladesh could also be affected.
Despite some remaining uncertainties, the scientific community feels that evidence for humans' role in influencing climate is strong enough to justify taking actions to reduce emissions.
We are responsible for in the increase rise of greenhouse gases from the combustion of fossil fuels and removal of CO2 absorbing vegetation. In 2005, National Academies of science in 11 countries believed that even though we lack complete knowledge of climate change, we should start taking action now (at a reasonable cost) to prevent further damage. Nations, like the U.S, have been reluctant to accept the issue amount the public as outdated debates and media skew what's actually happening despite the evidence. By 2007, awareness of the public on climate change was accepted due to CP Al Gore's 2006 film/book An Inconvenient Truth and 2007 IPCC respite on the internet. In 2009, a U.K hacker released thousands of documents about climate scientists to the public, though the story would be dismissed by deniers and the media, though panels on the investigation concluded that this evidence was no wrong doing. Also in 2009, the IPCC was in question about their info was misleading, so reforms were put in motion to strengthen their process of assessing to not tarnish the groups reputation..
