Environmental Science Final Exam Study Guide

Why is environmental science considered an interdisciplinary field that includes the natural and social sciences and the humanities?

Environmental science deals with the intersection of humans and their environment. Natural scientists gather and interpret data about the physical environment. Social scientists contribute by investigating how problems affect society and how societal choices impact the environment. Those in the humanities offer diverse ways to communicate information (e.g. through music, literature, or the visual and dramatic arts).

What are some sources of indoor air pollution you might face?

Common sources of indoor air pollution for Americans include cigarette smoke, pet dander, chemicals released from fabrics, carpet, and furniture, cleaners or solvents, and radon.

Which unconventional oil source currently being commercially produced has the lowest EROEI and the highest carbon footprint?

Tar sands oil

A watershed includes:

all the uphill land surrounding a river and its streams that can feed water into that river.

Air pollution is defined as:

contaminants in the air that cause environmental or health problems.

The first six air pollutants regulated by the Clean Air Act are known as _________ _________ _________.

criteria air pollutants

Habitat destruction that leads to a loss of niches can contribute to a loss of:

ecological diversity, ecosystem services and species diversity.

The forest layer that gets the most sunlight is the:

emergent layer.

Gulf of Mexico restoration steps such as improving coastal protections against storm damage, promoting low-impact community growth plans, and enhancing education and outreach are aimed at:

enhancing community resilience.

Aquifer infiltration is:

made harder in urban and suburban areas by roads, buildings, and lawns.

The goal of the Clean Water Act is to:

make environmental waters safe for fishing and swimming.

An example of species diversity might be the:

many different species inhabiting a swamp.

Identify at least one action we could take as a society to follow each of the four characteristics of a sustainable ecosystem.

1. Rely on renewable energy - we should move away from fossil fuels and increase our use of sustainable energy sources like solar, wind, geothermal or biomass based fuels (that are not harvested faster than they grow). 2. Use matter sustainably - recycling matter resources rather than throwing them away; reusing products; transitioning to non-toxic alternatives from toxic chemicals and industrial processes; improving product designs to reduce waste. 3. Population control - implement measures to reduce the population growth rate, such that human populations do not continue to grow. 4. Depend on local biodiversity - use local resources whenever possible (e.g. food, energy sources); use a variety of products or production methods, rather than relying on one or a few (i.e. using a wide variety of energy sources that reflect local availability and needs, rather than using the same energy source everywhere, i.e. fossil fuels).

After four half-lives, about how much radioactive parent material is left?

6.25%

Today, forests occupy approximately one-third of Earth's land area, account for over two-thirds of the leaf area of land plants, and contain about ________% of carbon present in living things.

70

Identify one behavior action that could reduce one's use of water for clothes washing and one water-efficient technology that could do so.

A behavioral action could be to only wash full loads of clothes and only wash clothes when they need it, not every time you wear them. A water-efficient technology could be an Energy Star washing machine that uses less water than traditional machines.

Which of the following has the greatest albedo?

A light-colored roof

Explain the premise behind agroecology.

Agroecology seeks to operate a farm in a way that takes into account the ecology of the local environment - modeling the farm after a functional ecosystem. Farming methods are chosen that enhance, rather than detract from, the environment's ability to produce the crop.

Which of the following is NOT part of the NEPA process?

All answers listed are part of the NEPA process.

Why is diversification such an important part of a renewable energy future?

All sources are not practical for every location, because all locations don't have abundant sunlight, water, wind, etc. The practicality of these depends on abundance, and abundance varies across the planet. Nevertheless, together, these renewable energy sources provide options, and we can choose the method or methods that work best in a given locale to meet the needs of the community.

What are some of the community impacts, both good and bad, of mountaintop removal (MTR) mining in Appalachia?

An advantage of MTR to the community would be local jobs provided by the mining operation, which could boost the local economy. Disadvantages include extreme environmental damage, increased risk of health problems from contaminated air and water, and decreased property values. If subsurface mines are closed or downsized due to competition from MTR mining, more jobs could be lost than created.

How might a restoration ecologist use an understanding of ecological succession to help repair a damaged area?

An ecologist who understands which species are present at any given stage of succession can use this knowledge to identify what successional stage a damaged community is currently in, and then bring in the appropriate species to help succession proceed. Taking other steps to physically alter the area (removing invasive species, restoring natural water flow, etc.) may also make it easier for the next successional stage to take root and grow.

Why is a change of a few degrees in average global temperature more concerning than day-to-day weather changes of a few degrees?

An increase in average global temperature means we should have more weather extremes that can cause problems.

Compare three typical point source pollutants and three nonpoint source pollutants from the area where you live.

Answers will vary, depending on whether the area is rural, suburban, or urban. Point source pollutants could be industrial or agricultural chemicals (see the Toxic Release Inventory of the EPA for specifics of a given zip code). Non-point source pollution could include fertilizer, pesticide and sediment runoff from farms, ranches, lawns, golf courses, construction sites, streets, and parking lots, or air pollutants that fallout and enter the water.

Why might it be useful to put a monetary value of the ecosystem services of forests, even if we know it is not exactly right?

By putting a price on the economic value of ecosystem services, we acknowledge that they are, in fact, valuable, and we get an idea of what it would take to replace them (for those that are replaceable). This can guide us to make better decisions about how to use our resources. For example, if we don't have pollinators to freely pollinate our crops, what would it take in manpower to do the job ourselves, and could we do it as well as pollinators? Maintaining healthy ecosystems that provide the pollinators to us for free, thus, appear to be a much better option.

What are the ecological problems associated with clear-cutting and when might it be ecologically beneficial to harvest timber using this method?

Clear-cutting can remove needed forest habitat and expose the soil to erosion, especially when done on a slope. Clear-cutting may be ecologically beneficial, however, if the intent is to remove a stand of diseased or invasive species of trees or to manage a species, such as deer, that needs edges or open areas. In this case, the clear-cut area should be done in a patchwork, not a vast area. It may also be appropriate in areas where forests are adapted to large-scale but infrequent destruction from storms or other natural disasters, such as the boreal forests of Canada.

Which of the following activities will NOT simultaneously protect forests and provide for long-term economic well-being of local people in developing countries?

Clear-cutting the forest and planting fast-growing trees for charcoal production

What role do conservation and diversification of energy sources play in achieving energy security or independence?

Conservation is helpful in achieving energy security or independence because it reduces the amount of energy needed, making it easier to meet needs with available energy sources. Diversification is also key, since this provides more energy options, reducing the need to rely on one or two energy sources to meet needs. The more sources accessed, the less each one needs to contribute to the energy supply.

Describe the link between desired fertility and the total fertility rate of a population and explain how they affect population growth.

Desired fertility and TFR tend to closely track one another, meaning that women tend to have the number of children they say they want to have. Both numbers are linked to population growth. As desired fertility increases, TFR increases; as TFR increases, so does population.

How is the current status of forests different in developing versus developed countries? What factors account for these differences?

Developed countries (like the United States) harvested their forests to support their industrialization in the past. Today, many of these countries have fewer stands of forests than developing countries, but they have more stringent regulations, better funding, and technical expertise to protect the forests that are left, keeping deforestation in check; many of their forests are in fact re-growing. On the other hand, developing countries (like Brazil and Indonesia) have far greater stands of forests, but are experiencing serious deforestation. While some of this deforestation is the result of domestic demand for forest resources (like charcoal in Haiti), much of it is driven to supply markets in the developed world with wood or agricultural commodities (such as beef, sugar, and palm oil) raised on cleared forests. The lack of regulations, or weak enforcement, makes it easy for multinational corporations to gain access to forests in the developing world and use them forthe benefit of markets in the developed world.

What is an "ecosystem service"? Describe three such services provided by forests.

Ecosystem services are resources (such as fertile soil and clean drinking water) and processes (such as decomposition and nutrient cycling) supplied by natural ecosystems that support life and make economic activity possible. Tree roots anchor soil and slow down the flow of rainwater, thus reducing flooding as well as recharging groundwater. Trees store a lot of carbon, making forests one of the largest carbon sinks in the world, and thus playing an important role in climate regulation. Trees provide many economic goods such as fuel, food, building materials, etc.

Which of the following is an air pollution source of volatile organic compounds (VOCs)?

Paints, solvents, carpets, household cleaners, and Wetlands

In nature, ____________ growth only occurs if there are no external limits such as food, space, and enemies.

Exponential

Identify three human actions that have led to an increase in the amount of greenhouse gases in the atmosphere. What has been the result?

Extra greenhouse gases are added to the atmosphere by humans by burning fossil fuels, through certain agricultural activities such as rice farming and rearing livestock, and the release of industrial chemicals like CFCs. The result has been a relatively rapid increase in average global temperatures, leading to climate change around the world.

Any ecosystem that contains trees is considered a forest.

False

Biodiversity hotspots are areas with many endemic species that are well protected and not threatened with endangerment.

False

Burning any fossil fuel generates air pollution, but natural gas is regarded as the fossil fuel that releases the most air pollution when burned.

False

Current CO2 levels in the atmosphere can be measured, but there are no good methods for determining CO2 levels in the distant past.

False

Density-independent factors tend to be biotic factors.

False

Farmers can use natural fertilizers, such as animal manure, to prevent nutrient runoff pollution.

False

Fracking uses a lot of water, but the wastewater produced is either recycled and used again or purified and pumped back into aquifers.

False

Garbage decomposes more quickly in a sanitary landfill than it would in an open dump.

False

Its vast deposits of shale oil and gas will allow the United States to meet all its energy needs with domestic sources into the foreseeable future.

False

Most air pollution deaths occur in high-income (developed) countries.

False

The Clean Water Act focuses primarily on reducing nonpoint source pollution.

False

The Safe Drinking Water Act (SDWA) establishes the basic structure for regulating discharges of pollutants into the waters of the United States and regulating quality standards for surface waters.

False

The primary purpose of environmental policies is environmental protection; human health and needs are a secondary concern.

False

The sector that uses the highest percentage of water globally is domestic use.

False

The use of fossil fuels is projected to decline in the next 50 years as the use of renewable energy sources increases.

False

Underground deposits that have oil or natural gas are known as conventional reserves.

False

When the true costs of electricity generation are considered, fossil fuels come out slightly better than renewables.

False

The National Environmental Policy Act (NEPA) was one of the ________ laws ever written that establishes the broad national framework for protecting our environment.

First

Explain the importance of fossil fuels to modern society.

Fossil fuels powered the Industrial Revolution that gave rise to modern society. Almost everything we do today requires fossil fuel inputs, and we cannot abandon them until we change our machinery and our infrastructure to accommodate different sources of energy.

Proponents of the "Gene Revolution" believe that:

GMOs are needed to achieve global food security.

Why is coal mine restoration more difficult at an Appalachian MTR site than at a Wyoming strip mine?

In Wyoming, the flat land allows miners to stockpile the overburden and topsoil and replace it after the coal seam is exhausted. It can then be replaced and vegetation similar to what was removed is replanted. However, in an MTR site, there is no place to store the vast quantities of overburden and soil. The very contour of the mountain is altered, because it is not feasible to rebuild the mountain, even if the overburden was retrievable. In addition, the natural ecosystem was forest, not grasses, but the soil that remains will not easily support trees, and the complexity of the forest cannot be replicated.

Compare the production of electricity by a wind turbine and the production of electricity by heating water to produce steam (thermoelectric production).

In both cases, the goal is to turn a turbine attached to a generator to produce electricity. With a wind turbine, the wind mechanically rotates the generator. With thermoelectric methods, steam turns the turbine to rotate the generator. The main difference is the production of waste products (emissions from burning a fuel or nuclear waste) from thermoelectric production. Another difference is scale and ease of increasing output on demand - a single coal or nuclear power plant can produce as much electricity as hundreds of wind turbines, and their output is more easily increased or decreased to match demand.

Why are some waste incinerators a better MSW disposal method than others?

Incinerators that use the heat generated to produce electricity are considered a better option than incinerators that simply burn the trash without energy capture. This way, we are using waste as resource and getting some benefit out if its disposal.

Which action would be taking a step to address the single biggest use of household water in the average U.S. home?

Installing a low-flow toilet

Which of the following is an advantage of generating electricity with a geothermal system?

It has a low carbon footprint.

Which of the following is a disadvantage to monoculture agriculture?

Large inputs of fertilizer are needed for high productivity.

Which of these is not an advantage of sustainable agriculture?

Less expensive

Which of these is an example of acting sustainably?

Meeting today's needs without compromising the ability of future generations to meet theirs

Explain the advantages and disadvantages to the use of monocultures in industrial agriculture.

Monocultures allow the farmer to more efficiently plant and harvest the crop, but they are also more vulnerable to pest infestations or disease, because once a pest or pathogen finds its way to a field, there is a huge food supply for it to feed on and it can quickly spread through the entire crop.

Which of the following statements is true about industrial agriculture?

Monocultures are preferred since they have high productivity.

Why is nuclear waste seen as a major, yet unresolved problem for the nuclear industry?

Nuclear waste is extremely radioactive and can be harmful to living organisms. Storing LLRW is not a big problem because of the low level of radiation of the material, but HHRW is much more problematic, because the material stays dangerously radioactive for a long time and produces a lot of heat, which makes storage inherently difficult. It is estimated that long-term storage needs to extend at least 10,000 years, but we do not currently have a long-term storage option in place.

Why were the health and environmental impacts so much more severe at Chernobyl than at Fukushima?

Officials did not notify people living near to, or downwind from, Chernobyl about the accident for many days, so many people were exposed to radiation without taking any precautions. Japanese officials immediately evacuated nearby areas and distributed iodine tablets to help combat the effects of radioactive iodine exposure. This protected the people in harm's way.

Why is it incorrect to assume that a stream that looks crystal clear is environmentally sound?

One should actually be concerned if there were no signs of organic material in a waterbody. It could be crystal clear because some toxin has killed off everything that lived in the water.

Identify several factors that contribute to the high growth rate in developing nations.

Poverty contributes to a high infant mortality rate and reduces life expectancy. This high rate of infant deaths likely contributes to a high birth rate, as families tend to have more children when the chance of child deaths is high. This high death rate is probably linked to poverty. (Niger has a very low per capita GNP.)

Of the 4 Rs, which is considered the "last" choice or least preferred action?

Recycle

Why is it unreasonable to reject an accepted scientific explanation on the basis that it is "just a theory"?

Rejecting a scientific explanation because it is "just a theory" implies a misunderstanding of what a scientific theory is. It is not a guess or even a hypothesis that can easily be discounted as having little or no supportive evidence. It represents the highest degree of certainty, and to reject it requires that all the supporting evidence also be rejected. To reasonably do that, one would need to provide alternate evidence that is at least as robust.

Distinguish between renewable energy and sustainable energy.

Renewability—the ability to be readily replenished over short time frames—is only one characteristic of a sustainable energy source. To be sustainable, an energy source must be used at a rate equal to or less than its replacement rate, and the environmental impacts of using the energy must be something we (and other organisms) can live with over the long term.

Explain the importance of the ability to store electricity for renewable energy to be a reliable source of electricity.

Renewables may not be consistent in their day to day (or hour to hour) production of electricity. Furthermore, that production may not be in line with needs. When demand is high, coal or nuclear production can be scaled up, but we cannot increase wind or solar radiation. However, if we could store excess electricity produced when production exceeds demand and access that stored energy as needed, this would address one of the biggest drawbacks of renewable energy—its reliability.

From an economic point of view, why is solid waste considered a mismanagement of resources?

Resources that are buried, lying in open dumps, or burned to ash may no longer be readily available to be reused and recycled. This reduces the matter available both to organisms in ecosystems and manufacturers looking for raw materials for production.

What role do biodiversity hotspots play in efforts to protect biodiversity?

Since biodiversity hotspots are areas with a lot of endemic species, threats to these areas will threaten species that are found nowhere else, and their loss would be an extinction, rather than an extirpation. Additionally, these hotspots have a lot of endangered species, so protecting them will protect many endangered species at once, making them a cost-effective choice in biodiversity protection programs.

Describe the types of problems that global climate change causes for human health. Which do you feel is likely to cause the biggest problem? Why?

Some problems include increases in weather-related mortality, infectious diseases, and respiratory illnesses. The impacts on agriculture will include lower crop yields; biomes will change in both species composition and range (leading to a loss of ecosystem function); water supply and quality will decline in many areas; coastal areas will be subject to increased erosion and flooding; and habitat loss will result in the loss of species. Student answers regarding the biggest problem will vary, but should be supported by evidence that explains why they feel this is the biggest problem.

How is biodiversity affected by climate change (both current and future)?

Some species will benefit and expand their range while others who can't adapt will decline or die out.

A disadvantage of solar power is that:

Start-up costs are high and Electricity can only be produced during the day.

Identify several strategies that could be used to restore water quality in the Gulf of Mexico?

Strategies to restore water quality would focus on preventing point source and nonpoint source pollution. Point source pollution prevention includes better regulation of industrial and municipal pollution sources. To reduce nonpoint source pollution, actions should be taken to prevent animal waste and fertilizer runoff from entering the water. This could be done by fencing off streams to keep animals out of the water, using less fertilizer (precision agriculture), taking steps to keep water on the farm field (controlled drainage), and planting riparian buffers to prevent runoff from reaching the streams and rivers that feed the Gulf of Mexico.

How does strip mining on flat ground compare to strip mining in mountainous areas in terms of environmental damage?

Subsurface mining employs more workers than MTR. MTR is safer for the worker, but not for the surrounding community; it does more damage to the area around the mine and leaves behind a very different ecosystem. Subsurface mining is more dangerous for workers, but has less impact on the surrounding community and ecosystem. Both mining methods can lead to the production of acid mine drainage as water washes through mined areas, picking up acidic compounds, but this is more of a problem with subsurface mines, including mine shafts that are closed or no longer used.

What did the Green Revolution accomplish and how did it do so? Discuss some of the unintended consequences of the methods used in the Green Revolution.

The Green Revolution increased food production (output/acre) tremendously by developing high yielding varieties of major food crops and providing them with fertilizers and irrigation to boost growth and pesticides to reduce loss to pests. The chemical additives can diminish soil fertility and contribute to water and soil pollution; pesticides are toxic to organisms other than just pests, and can disrupt nutrient cycles and even poison our own populations and that of other species. A loss of crop biodiversity can result if we limit ourselves to planting just a few varieties of crops, and heavy water use can damage soil or wash it away, as well as lead to water shortages. The social consequences of the Green Revolution were that farmers in nations that could afford the new farming technologies outcompeted the smaller farmers in developing nations (especially those of Africa), who then stopped farming, causing these nations to lose the ability to provide their own food.

Describe the final steps of fuel preparation from pellet to fuel assembly.

The enriched uranium is formed into small pellets and stacked into 3-6 meter (10-20 foot) long hollow fuel rods. More than 100 of these fuel rods are loaded into a framework to form fuel assemblies. Several fuel assemblies are placed into a thick-walled vessel—the reactor core—where they remain in place for a year or two before being removed and replaced with fresh fuel.

Which disadvantage of large dams can the smaller run-of-the-river dams avoid?

The environmental damage of creating a reservoir is avoided.

Which of the following is a disadvantage of sanitary landfills?

The extremely slow decomposition of the trash

Why are cardiovascular diseases linked to air pollution?

The heart must work harder to deliver oxygen to the body when the lungs are damaged.

In a nuclear fuel assembly, control rods are used to regulate the nuclear reaction. But even if all the control rods are inserted into the fuel assembly, heat is still produced. Explain why.

The nuclear material spontaneously decays, even if the fission reaction has been halted. This spontaneous decay generates heat. (This is why spent fuel rods still generate heat and must remain in a cooling water bath.)

Kangaroo rats eat seeds and are eaten by coyotes. Under what conditions might the kangaroo rat population increase logistically rather than exponentially?

The population size of kangaroo rats could increase if more food or nesting sites (or other limiting factors) became available, or if their predator, the coyote, declined in number. Their growth would slow to logistic growth as their population size approached carrying capacity (though, as an r species, they might overshoot and crash).

Why would one be more concerned about the venting of steam from a boiling water reactor than a pressure water reactor?

The water that surrounds and contacts the radioactive core in a boiler reactor is also the water that produces the steam that comes in contact with the turbines. In a pressure water reactor, the water that will become steam passes through the reactor core in a contained pipe and is not made radioactive itself. When steam must be vented to prevent a dangerous buildup of pressure, the steam from the boiling water reactor will be radioactive; therefore, you would be releasing radioactive material into the environment. Steam from the PWR is not radioactive, so no radiation would be directly released.

Why does education for girls and women usually reduce their total fertility?

They are more likely to secure birth control so they can control their own fertility.

What effect have recent large volcanic eruptions had on climate?

They contribute to cooling but only briefly.

Which of the following is not a characteristic of sustainable energy sources?

They must have no environmental impact.

Explain the potential risks associated with shipping tight oil.

Tight oil is very volatile and explosive, making shipping it dangerous. A train derailment of tight oil shipment resulted in a deadly explosion that leveled a town and killed 49 people. Other forms of crude oil are not as explosive and would be less likely to explode if a similar accident occurred.

Which of the following is an example of low-level radioactive waste (LLRW)?

Tools used by workers and worker clothing and gloves are both examples of LLRW.

What is transboundary pollution and why is it difficult to regulate?

Transboundary pollution is pollution that originated in one area but traveled to another. Conflicts can arise between states or nations suffering from transboundary pollution, because they do not have the political ability to regulate air pollution generated outside of their borders.

Air pollution can harm health, hurt the environment, and even damage buildings.

True

If we paid the true costs of using fossil fuels like coal, the price of our electricity would likely go up.

True

In most areas of developing countries, indoor pollution is more of a problem than outdoor pollution.

True

Modern U.S. environmental policy requires that environmental impacts be evaluated before federal action is taken.

True

Most freshwater on Earth is tied up in glaciers and ice caps.

True

Population growth rates tend to go down when job opportunities for women go up.

True

Potable water is water that is safe to consume.

True

Species that grow and reproduce quickly, and spread aggressively, with potential to cause harm, are given the label "invasive".

True

The higher the albedo of a surface, the better it reflects away sunlight.

True

Describe the policy of cap and trade. What are the advantages and disadvantages of this policy option?

Under cap and trade policy, the government issues pollution permits to each factory to meet an overall pollution target. Any permits that factories don't use (because they reduced emissions beyond requirements) can be sold to the other facilities that did not meet their allotment. The cost to the facilities who buy the permits is less than retrofitting and installing new equipment, and overall pollution is still reduced, because an overall cap was set that was below former pollution levels for the area. However, even if the overall pollution levels are reduced, the amount of pollution may vary by area - if factories in one area choose to buy extra permits, this can concentrate pollution in those areas.

What health problems are associated with coal burning?

Water pollution of toxic substances can contribute to a wide variety of health problems, depending on the toxin. Air pollution can directly impact the respiratory system. Overall health impacts from air and water pollution include birth defects and lung, heart, and kidney disease. There is also the danger of being hit by falling rocks and debris.

Which problems associated with the traditional use of coal are not addressed by using clean coal technologies?

While clean coal burns cleaner, all the problems associated with the mining of coal remain—you still have to get the coal.

What can lower the water table in an aquifer?

Withdrawing water faster than it is supplied; reducing the permeability of ground surfaces that prevent or slow infiltration will lower the water table.

How does deforestation contribute to loss of drinking water in Haiti?

Without the trees, the water rushes away rather than soaking into the ground to recharge groundwater supplies.

Dams can be used to store water and increase water supplies, but they come with trade-offs such as:

habitat destruction, loss of water from evaporation and regional conflicts downstream from the dam.

A nation that can reliably provide food for its citizens even if all the food is not grown locally is said to:

have food sovereignty.

The use of synthetic fertilizers on fields where crops are grown can:

increase crop yields, deplete the soil of other nutrients and contribute to water pollution.

The Green Revolution:

increased world food supplies but introduced new problems.

Exponential growth of a population:

is a J-shaped curve on a population graph.

The riparian area of a stream is the:

land area close enough to the water to affect it and be affected by it.

Recent sea-level rise is attributed to:

melting glaciers and thermal expansion of water.

Fertilizer from your lawn and motor oil from the leaky oil pan on your car are examples of:

nonpoint source pollution.

The number of individuals in a given area, such as an acre or a square mile, is a measurement known as ________ ________.

population density

A graph that shows human population size over the course of human history:

resembles a J-shaped curve—flat at first, with a rapid upward rise since about 1800.

If too much water is removed by a well in coastal areas:

saltwater can seep into the aquifer.

The understory of a forest is made up of:

shade-tolerant shrubs or the saplings of larger trees that sometimes form a lower canopy.

One creative way that some communities deal with wastewater is:

using partially treated wastewater to irrigate agricultural fields.

Day-to-day changes in meteorological conditions are known as _________________ whereas long-term patterns of meteorological conditions are known as _______________.

weather, climate