SCI 207
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Learning Objectives
After studying this chapter, you should be able to:
• Describe how mineral resources are mined and utilized and how these processes impact air quality, land, and water quality.
• Explain what a fossil fuel is and how fossil fuel deposits are classified on the basis of how concentrated they are and whether they are a conventional or unconventional deposit.
• Explain the “peak oil” concept and how future declines in oil production and supply could impact our economy and way of life.
• Explain the major challenges associated with a continued reliance on coal as an energy source and assess whether carbon capture and storage (CCS) techniques are a legitimate solution to these problems.
• Describe the arguments for and against the expanded development and use of unconventional shale gas deposits, including the environmental, economic, and social aspects of this issue.
• Explain the major ecological impacts of the 2010 Gulf of Mexico oil spill and how researchers are mak- ing use of the scientific method to distinguish between impacts caused by the spill and those caused by other factors.
Fossil Fuels and Minerals 6
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IntroDuCtIon
Pre-Test
1. the Environmental Protection Agency (EPA) reports that adults are at greater risk from exposure to lead than children.
a. true b. False 2. Shale gas is a conventional natural gas deposit. a. true b. False 3. oil companies are showing increasing interest in extracting oil from other hydrocarbon
resources such as tar sands and shale oil. a. true b. False 4. Geologic carbon sequestration involves separating out carbon dioxide that is created
when coal is converted to energy and transporting it to storage sites. a. true b. False 5. Hydraulic fracturing might pose a threat to the drinking water supply. a. true b. False 6. What does it mean that the death multiplier for cetaceans in the Gulf oil spill is said to be
around 50? a. the number of cetaceans dead from the oil spill is around 50. b. the number of cetaceans found dead multiplied by 50 gives an estimate of the num-
ber of actual deaths. c. the number of cetaceans eventually dying from effects of the oil spill will continue
for around 50 years. d. the recovery rate of cetaceans injured by the oil spill is about 50 animals per every
one found dead.
Answers 1. b. False. the answer can be found in section 6.1. 2. b. False. the answer can be found in section 6.2. 3. a. true. the answer can be found in section 6.3. 4. a. true. the answer can be found in section 6.4. 5. a. true. the answer can be found in section 6.5. 6. b. the number of cetaceans found dead multiplied by 50 gives an estimate of the number of actual deaths.
the answer can be found in section 6.6.
Introduction Fossil fuels and minerals are both found in the ground, and therefore they are both geologic resources—but they are dramatically different. Fossil fuels—coal, oil, and natural gas—are the accumulated remains of living organisms that were buried millions of years ago. Because these fuels were produced by living organisms, they are called organic materials. Mineral resources, on the other hand, are elemental deposits concentrated by physical processes within the Earth’s crust and are inorganic. one important distinction between fuel and min- eral resources is in the manner in which they become depleted. For example, coal is composed
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chiefly of carbon. When electric power plants burn coal, all of the energy in the coal is dis- sipated, and the carbon is converted into carbon dioxide. not one atom of carbon is lost, but the fuel is used up and cannot be retrieved. Fossil fuels are therefore nonrenewable in the sense that once they are burned, they cannot be replenished within tens, hundreds, or even thousands of years.
However, mineral resources are different. Geological processes concentrate minerals in cer- tain places, like the giant Mesabi iron ore range in Minnesota. ore is rock sufficiently enriched in one or more minerals to be mined profitably. Minerals are never used up, and they never disappear. Indeed, the aluminum can that holds your soft drink can be re-melted and reused. However, mineral reserves become effectively worthless, or essentially “lost,” if they are dis- persed. thus, if you throw that aluminum can in the trash and it gets mixed up with a lot of other garbage, it becomes prohibitively expensive to concentrate the metal again. today, min- eral resources are ubiquitous, from the steel in cars and bridges to the titanium in artificial joints and the silicon chips in your computer.
regardless of whether we are discussing fossil fuels or minerals, there are two critical facts that we need to consider as we begin this chapter. First, our modern way of life would simply not be possible without the exploitation and use of staggering quantities of fossil fuel and mineral resources. Second, the extraction and utilization of both fossil fuels and minerals is extremely environmentally destructive, resulting in air and water pollution, land disturbance, toxic waste emissions, and climate change impacts. these two facts set up a thorny challenge: How do we meet society’s need for minerals and energy in ways that don’t destroy our envi- ronment and poison us in the process?
this chapter will begin to explore that question by reviewing where minerals and fossil fuels come from, how we extract and use them, and what some of their environmental impacts are. In particular it probes some of the key challenges we currently face with our use of oil, coal, and natural gas. the following chapter looks more closely at probably the most significant environmental impact of fossil fuel use—global climate change. this is followed in Chapter 8 by a review of alternative energy sources and energy efficiency and how these might help to reduce some of the negative impacts associated with our current patterns of energy use. Chapter 9 considers issues of waste management and pollution, including a discussion of how recycling can help to reduce the need for new mineral mining and extraction. By the end of this chapter it should be clear just how environmentally destructive our appetite for minerals and fossils fuel energy is. therefore, the chapter ends with some suggestions for how each of us, as individuals, can reduce our energy and mineral use.
6.1 Mineral Resources and Mining We might not realize it, but we make use of many different kinds of minerals in our everyday life. The toaster and coffee maker in our kitchens have copper, aluminum, iron, and chromium in them. Our cell phones and smart phones might contain small amounts of tin, gold, tungsten, and so-called rare earth elements like tantalum. The walls of our homes or offices might consist of drywall produced from mined gypsum. Even the aluminum soft drink cans we open at lunch originated from a bauxite mine in a place like Australia or Jamaica. The process of mining min- erals from the ground, transporting them to where they are needed, refining them into a usable
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form, and manufacturing them into a finished product is extremely energy-intensive and entails significant environmental impacts at each step.
This short review of the environmental impacts of mining by Michael J. McKinley touches on some of the most obvious and immediate problems with this process. It starts with a basic review of minerals and the mining life cycle, followed by a discussion of environmental impacts and major mining laws and regulations in the United States and a handful of case studies. What this reading should make clear is that every product we use that includes a metal or minerals (which is just about everything) has an environmental impact that goes far beyond our immediate use and disposal.
This reading is different from the others in the chapter in that it focuses on the mining and extraction of non-fuel resources. Nevertheless, some of the same environmental issues involved in mining, transporting, and refining minerals also apply to fuel resources. For example, surface coal mining leads to many of the same land disturbance and water pollution problems as surface mining of minerals. Processing and refining oil and gas can be as energy- and pollution-intensive as metal refining. In that sense, this reading gives you a good starting point and overview of the kinds of environmental problems that occur whenever we dig material out of the Earth, whether it’s a mineral or fuel resource.
Another point to keep in mind as you complete this reading is the benefits of increased efficiency in our use of mineral and fossil fuel resources. A growing human population and rising stan- dards of living are pushing mineral and energy companies to exploit resources in more remote locations and under extreme conditions. However, re-use of minerals where possible and more efficient use of (or substitution for) fossil fuel resources can alleviate the need for some of this. For example, the simple act of recycling an aluminum can might seem like a good thing to do to reduce the amount of waste going into a landfill. In reality, the main environmental benefit of recycling aluminum is that a new container can be made from an old one rather than having to mine bauxite ore, transport it thousands of miles, refine it using massive amounts of energy, and manufacture it into a new can.
By Michael J. McKinley Modern mining is an industry that involves the exploration for and removal of minerals from the earth, economically and with minimum damage to the environment. Mining is important because minerals are major sources of energy as well as materials such as fertilizers and steel. Mining is necessary for nations to have adequate and dependable supplies of minerals and materials to meet their economic and defense needs at acceptable environmental, energy, and economic costs. Some of the nonfuel minerals mined, such as stone, which is a nonmetallic or industrial mineral, can be used directly from the earth. Metallic minerals, which are also non- fuel minerals, conversely, are usually combined in nature with other materials as ores. these ores must be treated, generally with chemicals or heat to produce the metal of interest. Most bauxite ore, for example, is converted to aluminum oxide, which is used to make aluminum metal via heat and additives. Fuel minerals, such as coal and uranium, must also be processed using chemicals and other treatments to produce the quality of fuel desired.
there are significant differences in the mining techniques and environmental effects of min- ing metallic, industrial, and fuel minerals. the discussion here will mostly concentrate on metallic minerals. Mining is a global industry, and not every country has high-grade, large, exceptionally profitable mineral deposits, and the transportation infrastructure to get the
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mined products to market economically. Some of the factors affecting global mining are envi- ronmental regulations, fuel costs, labor costs, access to land believed to contain valuable ore, diminishing ore grades requiring the mining of more raw materials to obtain the target mineral, technology, the length of time to obtain a permit to mine, and proximity to mar- kets, among others. the u.S. mining industry is facing increasing challenges to compete with nations that have lower labor costs—for example, less stringent environmental regulations and lower fuel costs.
Mining Life Cycle Minerals are a nonrenewable resource, and because of this, the life of mines is finite, and min- ing represents a temporary use of the land. the mining life cycle during this temporary use of the land can be divided into the following stages: exploration, development, extraction and processing, and mine closure.
Figure 6.1: Mining life cycle
A mining operation is a temporary use of land that includes the following in its life cycle: exploration, development, extraction and processing, and mine closure.
1. Exploration
• Use prospecting methods, such as exploratory drilling.
2. Development
• Prepare for extraction, including removing overburden.
3. Extraction and Processing
• Extract desired minerals and separate them from mineral concentrate.
4. Mine Closure
• Involves completion of reclamation plan to ensure safety of site for future use.
© Andrey Mirzoyants/iStock/Thinkstock; © Smileus/iStock/Thinkstock; © bondgrunge/iStock/Thinkstock; © Wirepec/iStock/ Thinkstock
Exploration is the work involved in determining the location, size, shape, position, and value of an ore body using prospecting methods, geologic mapping and field investigations, remote sensing (aerial and satellite-borne sensor systems that detect ore-bearing rocks), drilling, and other methods. Building access roads to a drilling site is one example of an exploration activity that can cause environmental damage.
the development of a mine consists of several principal activities: conducting a feasibility study, including a financial analysis to decide whether to abandon or develop the property;
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designing the mine; acquiring mining rights; filing an Environmental Impact Statement (EIS); and preparing the site for production. Preparation could cause environmental damage by excavation of the deposit to remove overburden (surface material above the ore deposit that is devoid of ore minerals) prior to mining.
Extraction is the removal of ore from the ground on a large scale by one or more of three prin- cipal methods: surface mining, underground mining, and in situ mining (extraction of ore from a deposit using chemical solutions). After the ore is removed from the ground, it is crushed so that the valuable mineral in the ore can be separated from the waste material and concentrated by flotation (a process that separates finely ground minerals from one another by causing some to float in a froth and others to sink), gravity, magnetism, or other methods, usually at the mine site, to prepare it for further stages of processing. the production of large amounts of waste material (often very acidic) and particulate emission have led to major environmental and health concerns with ore extraction and concentration. Additional pro- cessing separates the desired metal from the mineral concentrate.
the closure of a mine refers to cessation of mining at that site. It involves completing a reclamation plan and ensures the safety of areas affected by the operation, for instance, by sealing the entrance to an abandoned mine. Planning for closure is often required to be ongo- ing throughout the life cycle of the mine and not left to be addressed at the end of opera- tions. the Surface Mining and Control Act of 1977 states that reclamation must “restore the land affected to a condition capable of supporting the uses which it was capable of support- ing prior to any mining, or higher or better uses.” Abandoned mines can cause a variety of
health-related hazards and threats to the environment, such as the accumulation of hazardous and explosive gases when air no longer circulates in deserted mines and the use of these mines for residential or industrial dumping, posing a danger from unsanitary conditions. Many closed or abandoned mines have been identified by federal and state governments and are being reclaimed by both industry and government.
Environmental Impacts the environmental responsibility of mining operations is protection of the air, land, and water. Mineral resources were developed in the united States for nearly two centuries with few environmental controls. this is largely attributed to the fact that environmental impact was not understood or appreciated as it is today. In addition, the technology available during this period was not always able to prevent or control environmental damage.
Air All methods of mining affect air quality. Particulate matter is released in surface mining when overburden is stripped from the site and stored or returned to the pit. When the soil is removed, vegetation is also removed, exposing the soil to the weather, causing particulates to become airborne through wind erosion and road traffic. Particulate matter can be composed of such noxious materials as arsenic, cadmium, and lead. In general, particulates affect human
Consider This Do you think it’s really possible to restore an area that’s been surface mined to a “higher and better” use? What might this look like?
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health adversely by contributing to illnesses relating to the respiratory tract, such as emphy- sema, but they also can be ingested or absorbed into the skin.
Land Mining can cause physical disturbances to the landscape, creating eyesores such as waste- rock piles and open pits. Such disturbances may contribute to the decline of wildlife and plant species in an area. In addition, it is possible that many of the premining surface features can- not be replaced after mining ceases. Mine subsidence (ground movements of the earth’s sur- face due to the collapse of overlying strata into voids created by underground mining) can cause damage to buildings and roads. Between 1980 and 1985, nearly five hundred subsid- ence collapse features attributed to abandoned underground metal mines were identified in the vicinity of Galena, Kansas, where the mining of lead ores took place from 1850 to 1970. the entire area was reclaimed in 1994 and 1995.
Water Water-pollution problems caused by mining include acid mine drainage, metal contamination, and increased sediment levels in streams. Sources can include active or abandoned surface and underground mines, processing plants, waste-disposal areas, haulage roads, or tailings ponds. Sediments, typically from increased soil erosion, cause siltation or the smothering of streambeds. this siltation affects fisheries, swimming, domestic water supply, irrigation, and other uses of streams.
Acid mine drainage (AMD) is a potentially severe pollution hazard that can contaminate surrounding soil, groundwater, and surface water. the formation of acid mine drainage is a function of the geology, hydrology, and mining technology employed at a mine site. the primary sources for acid generation are sulfide minerals, such as pyrite (iron sulfide), which decom- pose in air and water. Many of these sulfide minerals originate from waste rock removed from the mine or from tailings. If water infiltrates pyrite- laden rock in the presence of air, it can become acidified, often at a pH level of two or three. this increased acidity in the water can destroy living organisms, and corrode culverts, piers, boat hulls, pumps, and other metal equipment in contact with the acid waters and ren- der the water unacceptable for drink- ing or recreational use. A summary chemical reaction that represents the chemistry of pyrite weathering to form AMD is as follows:
Pyrite 1 oxygen 1 Water → “Yellowboy” 1 Sulfuric acid
“Yellowboy” is the name for iron and aluminum compounds that stain streambeds. AMD can enter the environment in a number of ways, such as free-draining piles of waste rock that
AP Photo/Rick Smith
Acid mine drainage stains a creek bed orange in Pennsylvania. The state’s coal mines once employed hundreds of thousands of workers and produced more than one-quarter of the nation’s coal.
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are exposed to intense rainstorms, trans- porting large amounts of acid into nearby rivers; groundwaters that enter under- ground workings which become acidic and exit via surface openings or are pumped to the surface; and acidic tail- ings containment ponds that may leach into surrounding land.
Major U.S. Mining Laws and Regulations Some major federal laws and regulations affecting the mineral industry include the Com- prehensive Environmental response, Compensation and liability Act (CErClA), commonly known as Superfund, enacted in 1980. this law requires operations to report releases of haz- ardous substances to the environment and requires cleanup of sites where hazardous sub- stances are found. the Superfund program was established to locate, investigate, and clean up the worst abandoned hazardous waste sites nationwide and is currently being used by the u.S. Environmental Protection Agency (EPA) to clean up mineral-related contamination at numerous locations. the Federal Water Pollution Control Act, commonly referred to as the Clean Water Act, came into effect in 1977. the act requires mining operations to meet stan- dards for surface water quality and for controlling discharges to surface water. the resource Conservation and recovery Act (rCrA), enacted in 1976, regulates the generation, storage, and disposal of solid waste and hazardous waste, using a “cradle-to-grave” system, meaning that these wastes are governed from the point of generation to disposal. the national Envi- ronmental Policy Act (nEPA), enacted in 1970, requires federal agencies to prepare EIS for major federal actions that may significantly affect the environment. these procedures exist to ensure that environmental information is available to public officials and citizens before actions are taken. nEPA applies to mining operations requiring federal approval.
Examples of Mining Pollution and Reclamation the Bunker Hill Mine complex is located in northwest Idaho in the Coeur d’Alene river Valley, and has a legacy of nearly a hundred years of mining-related contamination since 1889. oper- ations ceased in 1982, and the EPA declared much of the area a Superfund site in 1983. the complex produced lead, zinc, cadmium, silver, and gold, as well as arsenic and other minerals and materials. Much of the mining pollution was caused by the dispersal of mining wastes containing such contaminants as arsenic, cadmium, and lead into the floodplain of the Coeur d’Alene river, acid mine drainage, and a leaking tailings pond. the metals contaminated soils, surface water, groundwater, and air, leading to health and environmental effects. lead, in par- ticular, was noted for its health effects on children in the area. EPA reports concerning lead poisoning state that experts believe blood levels as low as 10 micrograms per deciliter (mg/dl) are associated with children’s learning and behavioral problems. High blood lead levels cause devastating health effects, such as seizures, coma, and death. Blood levels of children in areas near the complex ranged from about 35 to 65 mg/dl in the early 1970s to less than 5 percent in 1999, as remediation efforts progressed. EPA reports also state that children are at a greater risk from exposure to lead than adults because, among other reasons, children absorb and retain a larger percentage of ingested lead per unit of body weight than adults, which increases the toxic effects of the lead. Efforts by the federal government, the state of Idaho, and industry to remediate contaminated areas associated with the site are ongoing.
Consider This Briefly summarize the major environmen- tal impacts of mineral mining to air quality, land, and water quality
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there are also many mines with successful reclamation plans. For example, the ruby Hill Mine, which is an open pit gold mine in Eureka, nevada, won a state award in 1999 for concur- rent reclamation practices, such as using revegetation and employing mitigation measures to offset potential impacts to local wildlife.
the mining of asbestos, either as the primary mineral or included as an unwanted material while mining for the “target” mineral, is one of the more controversial issues facing the min- ing industry in the united States. Asbestos is the name given to a group of six naturally occur- ring fibrous minerals. Asbestos minerals have long, strong, flexible fibers that can be spun and woven and are heat-resistant. Because of these characteristics, asbestos materials became the most cost effective ones for use in such items as building materials (roof coatings and shingles, ceiling and floor tiles, paper products, and asbestos cement products) and friction products (automobile clutch, brake, and transmission parts).
unfortunately, it has been found that long-term, high-level exposure to asbestos can cause asbestosis and lung cancer. It was also determined that exposure to asbestos may cause meso- thelioma, a rare form of cancer. Workers can be exposed to asbestos during mining, milling, and handling of ores containing asbestos or during the manufacture, installation, repair, and removal of commercial products that contain asbestos. one of the more recent controversies involving asbestos is the exposure of workers and the local residents to asbestos found in vermiculite ore mined in libby, Montana. the vermiculite ore was shipped nationwide for processing and was used for insulation, as a lightweight aggregate, in potting soils, and for agricultural applications. Mining of the libby deposit ended around 1991 but elevated levels of asbestos-related disease have been found in the miners, millers, and the local population. Another major area of concern is naturally occurring asbestos found in rock outcrops in parks and residential areas.
Adapted from Pollution A to Z, 1E. © 2004 Gale, a part of Cengage Learning, Inc. Reproduced by permission. www.cengage.com/permissions
6.2 Fossil Fuel Resources While the previous reading dealt with mineral resources, this reading and the remainder of the chapter will focus on fuel resources. If you were to casually skim the Internet and look for infor- mation on how much oil, coal, or natural gas (known as fossil fuels because they were formed from ancient plants and organisms over hundreds of millions of years) is “left” for us to use, you would encounter very different numbers. The main reason for this is that geologists and other scientists who study fossil fuels break these deposits into different categories depending on whether they are well understood and easily available or based mostly on scientific specula- tion and located in difficult-to-reach locations. The report below by specialists in energy at the Congressional Research Service helps explain the various categories used to classify fossil fuels and what this means for our understanding of how much of these fuels might still be available.
Even though there are many different terms and categories used to classify fossil fuel deposits, there are two primary breakdowns on which geologists focus. The first has to do with how con- centrated and easily accessible a fossil fuel deposit is. The authors of this report use the idea of a resource pyramid to express this. Highly concentrated and easily accessible fossil fuels make up
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the top of the pyramid. These are the fuels that energy companies exploit first because they have the lowest production costs. An example of this would be oil deposits that literally gush oil once tapped or high-quality coal seams very close to the Earth’s surface. For the most part, these highly concentrated and easily accessible deposits have already been exploited, and so energy compa- nies “move down” the pyramid to more numerous, but also more difficult to develop, deposits. Such deposits are usually less concentrated, are more remote, and may require more effort to develop. Examples of this would be drilling for oil deep offshore or having to inject steam or hot water into an oil deposit to bring that oil to the surface. Further yet down the pyramid are more numerous deposits of fossil fuels that are of such low concentrations and/or in very difficult-to- reach locations that it does not make any economic sense to extract them unless energy prices go much higher. In this way you could say that we don’t really “use up” fossil fuels, we just consume those deposits that are concentrated and accessible enough to make economic sense.
A second category of difference for classifying fossil fuels involves whether a source is conven- tional or unconventional. Historically we have exploited conventional deposits of oil and gas, which are found in porous (made up of void spaces able to hold fluid) rock formations. Tra- ditional drilling techniques were used to bring the oil and gas to the surface of such deposits. However, geologists have long realized that oil and gas are also found in unconventional depos- its, such as oil-soaked sands or shale formations that have trapped gas. Such unconventional resources are more difficult to exploit and generally have greater environmental impacts in pro- duction. Because many conventional deposits have already been heavily exploited and energy prices are rising, unconventional deposits are now the focus of much more attention than they were in the past.
For example, shale gas is described briefly in this section and in more detail in section 6.5. The fact that energy companies are now going to such great lengths—including use of a contro- versial technique known as hydrofracturing (hydraulic fracturing) or “fracking”—to exploit shale deposits is a sure sign of how vast our appetite for energy actually is. While this reading is mostly silent on the subject, it remains the case that the extraction and use of fossil fuels is among the most environmentally destructive of all human activities. For this reason, efforts to develop renewable energy resources and use energy more efficiently (see Chapter 8) are critical.
By Gene Whitney, Carl E. Behrens, and Carol Glover Current discussions of u.S. and global energy supply refer to oil, natural gas, and coal using several terms that may be unfamiliar to some. the terms used to describe different types of fossil fuels have technically precise definitions, and misunderstanding or misuse of these terms may lead to errors and confusion in estimating energy available or making compari- sons among fuels, regions, or nations. this report describes the characteristics of fossil fuels that make it necessary to use precise terminology, summarizes the major terms and their meanings, and provides a brief summary of the united States’ endowment of fossil fuels and the relationship between the u.S. fossil fuel energy endowment and those of other nations.
Characteristics of Fossil Fuels Fossil fuels are categorized, classified, and named using a number of variables. It is impor- tant to keep in mind that naturally occurring deposits of any material, whether it is fossil fuels, gold, or timber, comprise a broad spectrum of concentration, quality, and accessibility
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(geologic, technical, and cultural). these characteristics can be portrayed as a resource pyra- mid. At the top of the pyramid are the deposits that are high quality and easy to access. these deposits have been generally discovered and produced first. Examples of the deposits at the top of the resource pyramid are the large oil deposits of Saudi Arabia and the enormous natu- ral gas deposits of Qatar. Moving down the pyramid, the quality and/or accessibility declines, and production becomes more difficult and expensive. A large oil deposit in the deep waters of the Gulf of Mexico would be further down the pyramid than a comparable deposit on land because of the added expense and technology required to produce it.
It is important to note that the deposits at the bottom of the pyramid may be quite extensive. Deposits may be of poor quality or diffuse, but may occur in vast quantities. Examples of fos- sil fuel deposits that would be found at the bottom of the pyramid are oil shale and methane hydrates.
Oil shale and methane hydrate deposits contain massive amounts of oil and natural gas, but their mode of occurrence, poor accessibility, and difficult recovery make them difficult to pro- duce and/or subeconomic currently. the economic threshold for producing deposits further down the pyramid is partly a function of commodity price. that threshold is also moved by the development of new extraction technologies that make production feasible at lower cost.
For u.S. oil deposits, the resource pyramid indicates that many of the high-quality, easy-to-find deposits have already been produced. Current proved reserves (see “terminology” below) include many deposits that are of lower quality or with poorer access than some historical production, but which are still economic under current market conditions. As long as demand
for oil continues, the exploration and pro- duction process will move down the pyra- mid under the influences of price (includ- ing environmental costs in some cases) and technology. Whether the vast depos- its of oil shale that are lower on the pyra- mid will be produced depends on the price of oil, the cost of production (includ- ing environmental cost), and the availabil- ity of technology to produce it. Although this example is for oil, similar relation- ships exist for natural gas and coal.
Terminology A search for energy statistics in the literature quickly reveals a large number of terms used to describe amounts of fossil fuels. Most of these terms have precise and legitimate defini- tions, and even a careful comparison of statistics for diverse forms of fossil fuels can become quite difficult to reconcile or understand. not only do oil, natural gas, and coal occur in many diverse geologic environments, but each commodity may occur in different modes or in dif- ferent geologic settings that impose vastly different economics on their recovery and delivery to market. A vocabulary of terms has developed over the decades to capture the nature of deposits in terms of their likelihood of being developed and their stage of development.
Consider This Why do energy companies exploit fossil fuel deposits near the top of the resource pyramid first? What factors force or enable them to move down the resource pyramid to lower-quality deposits?
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Examples of terms used for fossil fuel deposits (not an exhaustive list) include:
• Proved reserves • Probable reserves • Possible reserves • unproved reserves • Demonstrated reserve base • undiscovered resources • Probable resources • Possible resources • Speculative resources • Potential resources • technically recoverable resources • Economically recoverable resources
two particularly important distinctions afford a better understanding of fossil fuel statistics. the first key distinction is between proved reserves and undiscovered resources; the second key distinction is between conventional and unconventional deposits of fossil fuels.
Proved Reserves and Undiscovered Resources For oil and natural gas, a major distinction in measuring quantities of energy commodities is made between proved reserves and undiscovered resources. understanding these terms will help avoid confusion about statistical energy data.
Proved reserves are those amounts of oil, natural gas, or coal that have been discovered and defined at a significant level of certainty, typically by drilling wells or other exploratory measures, and which can be economically recovered. In the united States, proved reserves are typically measured by private companies, who report their findings to the Energy Information Administration (EIA), and to the Securities and Exchange Commission because those reserves are considered capital assets. Because proved reserves are defined by strict rules, they do not include all of the oil or gas in a region, but only those amounts that have been carefully confirmed.
Because proved reserves are, by definition, economically recoverable, the proportion of the oil in the ground that qualifies as proved reserves grows when prices are high, and shrinks when prices are low. that is, even without new discoveries, oil that may be subeconomic at $70 per barrel might become economic at $100 per barrel and so the total proved reserves increase simply because price increases. In addition to the volumes of proved reserves are deposits of oil and gas that have not yet been discovered, which are called undiscovered resources. the term “resource” has often been used in a generic sense to refer to quantities of energy (or other) commodities in general. observers may refer to resource-rich nations, or speak about a large resource base, for example. But the term “undiscovered resources” has a specific mean- ing. undiscovered resources are amounts of oil and gas estimated to exist by examining geo- logic characteristics in unexplored areas. Estimates of undiscovered resources for the united States are made by the u.S. Geological Survey for resources on land, and by the u.S. Bureau
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Consider This Explain why levels of proved reserves for oil and other fossil fuels can change dramatically based solely on changes in energy prices.
of ocean Energy Management, regulation and Enforcement (formerly the Miner- als Management Service) for resources offshore. these assessments are based on observation of geological character- istics similar to producing areas and many other factors. reported statistics for undiscovered resources may vary greatly in precision and accuracy (deter- mined retrospectively), which are directly dependent upon data availability, and their quality may differ for different fuels and different regions. Because estimates of undiscov- ered resources are based partly on current production practices, they are generally reported as undiscovered technically recoverable resources.
Another term sometimes used in the fossil fuels literature is “in-place” resources. In-place resources are intended to represent all of the oil, natural gas, or coal contained in a formation or basin without regard to technical or economic recoverability. Because only a small propor- tion of the total amount of the fossil fuel in a deposit is ever recovered, there are often large discrepancies between volumes of in-place resources and the proportion of those resources that are technically recoverable. In-place resource estimates are sometimes very large num- bers, which may be misleading if the reader does not appreciate that usually only a small proportion of the in-place volume of a resource can ever be produced or recovered.
Conventional Versus Unconventional Oil and Natural Gas Deposits the first oil and gas deposits discovered consisted of porous reservoirs in geologic forma- tions, capped by an impervious rock “trap” within which migrating fluids such as oil, natural gas, and water would accumulate. Within the reservoir, natural gas would be the least dense fluid and would have accumulated at the top of the reservoir. oil is more dense than gas, but less dense than water and would pool in a layer below the gas cap. Below the oil and gas, water would fill the confined reservoir. this layered arrangement of natural gas, oil, and water within a reservoir is called a conventional deposit and has historically provided most of the oil and natural gas that has been produced.
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Figure 6.2: Conventional deposits
In a conventional deposit, natural gas accumulates above more dense oil reserves.
In recent decades, geologists began to realize that considerable volumes of oil and natural gas exist outside conventional reservoirs in sedimentary rocks situated in geologic basins. the distribution of oil or natural gas throughout a geologic formation over a wide area, but not in a discrete reservoir, is called an unconventional deposit (sometimes called a con- tinuous deposit). the amounts of oil and gas contained in unconventional deposits may be very large, but recovering those deposits is sometimes difficult and expensive. oil sands provide an example of an unconventional oil deposit in which the oil is distributed widely through the sandstone formation. recovering the oil from oil sands requires special technolo- gies and treatments such as heating, steam flooding, or even excavation. An example of an
Natura l Gas
Oil
Water
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unconventional natural gas deposit is coalbed methane. the natural gas (methane) does not exist in a discrete reservoir but is distributed throughout the pore spaces of coal and held in place by water. When the water is removed from the coal, the gas is released and can be pro- duced. Another type of unconventional natural gas deposit is shale gas, which is discussed below (see “Shale Gas”).
there is no direct correlation between the economic recoverability of a deposit and whether it is conventional or unconventional. Some conventional deposits are not economically recov- erable because they are too small, too deep, or lack surface access. on the other hand, certain unconventional deposits such as oil sands and coalbed methane are economically recoverable in some locations.
Oil Shale After coal, oil shale represents the most abundant fossil fuel in the united States. However, despite government programs in the 1970s and early 1980s to stimulate development of the resource, production of oil shale is not yet commercially viable. the need for massive capital investment and the cost of production itself have been the major barriers. A further economic factor lies in the fact that liquids produced from oil shale have a unique chemical composi- tion and, unlike conventional crude oil, cannot be distilled to produce gasoline, but would be primarily a source of other liquid middle distillate fuels such as jet fuel or diesel oil, fuels for which there is significant national demand. In addition, production of liquids from oil shale requires large amounts of water, an important factor since most of the resource is located in water-scarce regions of western Colorado, utah, and Wyoming. other environmental prob- lems include the difficulty in disposing of tailings if excavation is used as the extraction pro- cess, and the production of greenhouse gases. In light of these difficulties, efforts to aid in the development of oil shale are focused on pilot projects to test alternative technologies of production.
Shale Gas Shale gas is an emerging type of natural gas deposit, and exploration for and production of shale gas is increasing. Some shale gas is currently economic, and improved production methods are leading to increasing production. Shale gas is a classic unconventional type of deposit; the gas is distributed throughout the low-permeability shale formations rather than accumulating in a more permeable reservoir. the occurrence of gas in this manner requires special production techniques that often involve horizontal drilling into the gas-bearing for- mation, followed by hydrofracturing of the rock (exerting pressure in the gas well so high that it causes brittle rock to fracture) to release the gas from the rock. the use of hydrofrac- turing has caused some environmental concerns arising from the injection of large amounts of water into the well, concerns about the chemical composition of the injected fluids, dis- posal of production fluids after hydrofracturing is completed, fears that the fractured rock will expose local water wells to non-potable waters, and the observation that some hydro- fracturing jobs have apparently created small earthquakes. However, industry officials insist that any environmental concerns could be mitigated through careful production practices
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[see section 6.5 for more on this controversy]. of the current total, u.S. natural gas proved reserves of 283.9 tcf (trillion cubic feet); EIA includes 60.6 tcf of proved reserves as shale gas. no systematic assessment of undiscovered technically recoverable shale gas resources has been conducted for the united States, though industry and academic experts estimate that the technically recoverable volumes of natural gas from these shale deposits are very large. the Potential Gas Committee has estimated that the united States has 616 tcf of “potential natural gas resources” occurring as shale gas. the proportion of that resource that will actually be produced will depend on further development of exploration and production technology, the price of natural gas, and the ways in which states deal with potential environmental issues. However, EIA has significantly increased the projections for shale gas production in its 2011 Annual Energy outlook.
Methane Hydrates Another form of fossil fuel with potentially vast resources is natural gas in the form of meth- ane hydrate. Methane hydrate (sometimes called natural gas hydrate, or just gas hydrates) is being investigated as an energy source by both DoE and uSGS. Methane hydrate is a crys- talline solid composed of methane and water that forms in porous rocks under very spe- cific conditions of temperature and pressure. Deposits occur most commonly offshore in the sediments or rocks of the continental shelf and slope, or in cold climates such as northern Alaska and Canada. Although considered a scientific oddity until the 1990s, methane hydrates are now known to exist in hundreds of locations around the world, often in small, isolated deposits, but sometimes in massive quantities. total worldwide in-place resources of meth- ane hydrates are probably huge, perhaps thousands of trillion cubic feet, but hydrates have never been produced commercially.
Current efforts by the united States, Canada, Japan, India, and several other nations are aimed at developing technologies to exploit this large and widespread form of natural gas. the mean in-place gas hydrate resource for the entire united States is estimated to be 320,000 tcf of gas, with approximately half of this resource occurring offshore of Alaska and most of the remain- der occurring beneath the continental margins of the lower 48 states. the uSGS estimates that
there are about 85 tcf of undiscovered technically recoverable gas resources within gas hydrates in northern Alaska, and recent studies have shown that methane hydrates are more abundant in the sediments of the Gulf of Mexico than previously believed. Improved under- standing of the occurrence and behavior of these important natural gas deposits, and improved technology for produc- ing them, may make methane hydrates a viable source of natural gas in the future.
Consider This Discuss the difference between the uncon- ventional fossil fuel resources of oil shale, shale gas, and methane hydrates. What are some of the challenges and problems asso- ciated with the extraction of these energy sources?
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U.S. Coal Reserves and Resources EIA is the authoritative source for coal reserves and resource estimates for the united States. EIA compiles data on coal reserves and resources from state sources and federal sources, including from geologic assessment work done by the uSGS. the terminology used for coal is slightly different than for oil and natural gas. the primary statistic reported by EIA is the demonstrated reserve base (DrB), which is comprised of coal resources that have been identified to specified levels of accuracy and may support economic mining under current
technologies. For the latest reporting period, calendar year 2007, the u.S. demonstrated reserve base was 486 billion short tons. Because the united States produces and consumes about 1 billion short tons of coal per year, the demonstrated reserve base would appear to provide hundreds of years’ supply of coal, if u.S. users continue to consume it at the same rate. How- ever, because coal production often requires ground disturbance, espe- cially for open-pit mining, the amount that is technically recoverable is not always available. EIA has applied an availability factor that reduces the technically recoverable amount to 261 billion short tons that would actually be available for mining. Detailed avail- ability studies by the uSGS have indi- cated that, at least in some cases, the
available and economically recoverable coal might be substantially less than the technically recoverable amount for a variety of reasons: a significant portion of the coal resources less than 4,000 ft (1,219.2 m) in depth are also typically subeconomic due to a number of restric- tions that further limit their availability and recoverability. Some of these restrictions are technical constraints (using existing technology) such as coal beds too thin to recover or dip- ping too steeply. Many societal or environmental restrictions such as the presence of towns, wetlands, or other environmentally sensitive areas may also preclude coal recovery. Both regional mine planning and economic studies are necessary to derive estimates of the coal reserves for any given area. For example, in one specific case in Wyoming, 47% of the in-place coal is technically recoverable, but the available, economically recoverable coal is only about 6% of the in-place coal. While these proportions may vary between 5% and 20%, depending upon the specific conditions for each coal-mining area, very large coal numbers are viewed with some caution because in-place numbers, or even recoverable numbers, may not provide a realistic assessment of the coal that could actually be produced.
Adapted from Whitney, G., Behrens, C. E., and C. Glover, C. (2011). U.S. Fossil Fuel Resources: Terminology, Reporting, and Summary. Congressional research Service. Retrieved from http://epw.senate.gov/public/index.cfm?Fuse Action=Files.view&FileStore_id=04212e22-c1b3-41f2-b0ba-0da5eaead952
© Rasica/iStock/Thinkstock
An open-pit coal mine in the United States. Open- pit mining operations often require significant disturbances to the ground and surrounding environment.
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6.3 Peak Oil Most people alive today have lived their entire lives in what is known as the Age of Oil. Not only are we reliant on oil for our cars, but we depend on this resource in countless other ways. Oil is the raw material for many forms of plastics and synthetic fibers, and our modern agricul- tural system could not run without massive inputs of oil for fertilizer and pesticide manufacture. Therefore, the possibility that we will soon pass, or have already passed, a peak in oil production should be a matter of great concern. In this reading Richard Heinberg, senior fellow-in-residence at the Post Carbon Institute, argues that “peak oil” could pose the greatest economic challenge to our way of life since the start of the Industrial Revolution. Peak oil is defined in this reading as the point when petroleum extraction globally reaches its maximum and begins an inevitable decline.
The peak oil concept is the subject of much disagreement and debate, mainly because of uncer- tainties over just how much oil remains in the ground and how much of that oil is actually recov- erable. While this reading acknowledges that uncertainty and the difficulty of knowing when exactly any peak is reached, it argues that business-as-usual assumptions of unending oil sup- plies are foolish for a number of reasons. First, oil is such a critical resource to our economy and way of life that we should be better prepared for any potential disruption to its supply. Second, developing countries like China are witnessing sharp increases in demand for oil and contribut- ing to increases in world oil prices. Third, an increasing trend of producing oil from unconven- tional sources (e.g., tar sands) is leading to significant environmental impacts in production and, in an ominous sign, requiring ever-increasing use of energy-intensive extraction techniques.
A final point to consider in the peak oil debate (and with the use of all fossil fuels, for that mat- ter) has to do with the impact of consumption on climate change. Regardless of whether we have already reached a point of peak oil or not, we cannot continue to utilize fossil fuels without impacting the climate. As suggested in the introduction to this chapter, even without the climate change issue, all fossil fuel production and use leads to significant environmental impacts. As such, the suggestions presented at the end of this reading for how to reduce oil consumption could apply to the utilization of all fossil fuels.
By Richard Heinberg During the past decade a growing chorus of energy analysts has warned of the approach of “peak oil,” when the global rate of petroleum extraction will reach its maximum and begin its inevitable decline. While there is some dispute among experts as to when this will occur, there is none as to whether. the global peak is merely the cumulative result of production peaks in individual oil fields and in oil-producing nations. the most important national peak occurred in the united States in 1970. At that time America produced 9.5 million barrels per day (mbd) of oil; the current figure is less than 6 mbd. While at one time the united States was the world’s top oil-exporting nation, it is today the world’s top importer.
the u.S. example helps in evaluating the prospects for delaying the global peak. After 1970, exploration efforts succeeded in identifying two enormous new American oil provinces—the north Slope of Alaska and the Gulf of Mexico. Meanwhile biofuels (principally ethanol) began to supplement crude. Also, improvements in oil recovery technology helped to increase the proportion of the oil in existing fields able to be extracted. these are the strategies (explora- tion, substitution, and technological improvements) that the energy industry is relying on either to delay the global production peak or to mitigate its impact. In the united States, each of these strategies made a difference—but not enough to reverse, for more than a few years
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now and then, a forty-year trend of declining production. the situation for the world as a whole is likely to be similar.
How near is the global peak? today most oil-producing nations are seeing reduced output. In some instances, these declines are occurring because of lack of investment in exploration and production, or domestic political problems. But in most instances the decline results from factors of geology: While older oil fields continue to yield crude, beyond a certain point it becomes impossible to maintain maximum flow rates. Meanwhile, global rates of discovery of new oil fields have been declining since 1964.
these two trends—a growing preponderance of past-peak producers and a declining success rate for exploration—suggest that the world peak may be near. the consequences of peak oil are likely to be devastating. Petroleum is the world’s most important energy resource. there is no ready substitute, and decades will be required to wean societies from it. Peak oil could therefore pose the greatest economic challenge since the dawn of the Industrial revolution. For policy makers, five questions seem paramount:
1. How Are the Forecasts Holding Up? While warnings about the end of oil were voiced in the 1920s and even earlier, the scientific study of petroleum depletion began with the work of geophysicist M. King Hubbert, who in 1956 forecast that u.S. production would peak within a few years of 1970 (in fact, that was the exact peak year), and who went on to predict that world production would peak close to the year 2000.
Shortly after Hubbert’s death in 1989, other scientists issued their own forecasts for the global peak. Foremost among these were petroleum geologists Colin J. Campbell and Jean laherrère, whose article “the End of Cheap oil,” published in Scientific American in March 1998, sparked the contemporary peak oil discus- sion. In the following decade, publica- tions proliferated, including dozens of books, many peer-reviewed articles, websites, and film documentaries.
Most of the global peaking dates fore- cast by energy experts in the past few years have fallen within the decade from 2005 to 2015. running coun- ter to these forecasts, IHS CErA, a prominent energy consulting firm, has issued reports foreseeing no peak before 2030.
Are events unfolding in such a way as to support near-peak or the far-peak forecasts? According to the Interna- tional Energy Agency, the past seven years have seen essentially flat pro- duction levels. these years have also
© ping han/iStock/Thinkstock
An increasing number of energy experts, including many former geologists from within the oil industry itself, believe that global oil production has peaked. Are we approaching the sunset of the Oil Age?
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seen extremely high oil prices, which should have provided a powerful incentive to increase production. the fact that actual crude oil production has not substantially increased during this period strongly suggests that the oil industry is near or has reached its capacity limits. It will be impossible to say with certainty that global oil production has peaked until several years after the fact. But the notion that it may already have reached its effective maximum must be taken seriously by policy makers.
2. What About Other Hydrocarbon Energy Sources? If oil is becoming more scarce and less affordable, it would make sense to replace it with other energy sources, starting with those with similar characteristics—such as alternative hydrocarbons. there are very large amounts of total hydrocarbon resources; however, each is constrained by limits of various kinds. Bitumen (often called “oil sands” or “tar sands”), kerogen (sometimes referred to as “oil shale”), and shale oil (oil in low-porosity rocks that requires horizontal drilling and hydraulic fracturing for recovery) do not have the economic characteristics of regular crude oil, being more expensive to produce, delivering much lower energy return on investment, and entailing heavier environmental risks. Production from these sources may increase, but is not likely to offset declines in conventional crude over time.
Coal is commonly assumed to exist in nearly inexhaustible quantities. It could be used to produce large new amounts of electricity (with electric transport replacing oil-fueled cars, trucks, and trains), and it can be made into a liquid fuel. However, recent studies have shown that world coal reserves have been severely overestimated. Meanwhile, China’s spectacular coal consumption growth virtually guarantees higher coal prices globally, making coal-to- liquids projects impractical.
natural gas is often touted as a potential replacement for both oil and coal. However, conven- tional gas production in the united States is in decline. unconventional gas production via hydraulic fracturing (“fracking”) is increasing supplies over the short term, but this new pro- duction method is expensive and entails serious environmental risks; also, fracked gas wells deplete quickly, necessitating very high drilling rates.
thus, while in principle there are several alternative hydrocarbon sources capable of substi- tuting for conventional crude oil, all suffer from problems of quality and/or cost.
3. What Might Happen in the Next Decades Absent Policies to Address Peak Oil?
the likely consequences of peak oil were analyzed at some length in the report, “Peaking of World oil Production: Impacts, Mitigation, and risk Management” (also known as the Hirsch report), commissioned for the u.S. Department of Energy and published in 2005. that report forecast “unprecedented” social, economic, and political impacts if efforts are not undertaken, at a “crash program” scale, and beginning at least a decade in advance of the peak, to reduce demand for oil and initiate the large-scale production of alternative fuels.
Clearly, the level of impact will depend partly on factors that can be influenced by policy. one factor that may not be susceptible to policy influence is the rapidity of the post-peak rate of decline in global oil production. the Hirsch report simply assumed a 2 percent per year
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decline. In the first few years after peak, the actual decline may be smaller. that rate may increase as declines from existing fields accumulate and accelerate.
However, for some nations the situation may be much worse, since available oil export capac- ity will almost certainly contract faster than total oil production. Every oil-exporting nation also consumes oil, and domestic demand is typically satisfied before oil is exported. Domestic oil demand is growing in most oil-producing nations; thus the net amount available for export is declining even in some countries with steady overall production. nations that are major oil importers, such as the united States, China, and many European nations, will feel strongly the effects of sharp declines in the amount of oil available on the export market.
High prices and actual shortages will dramatically impact national economies in several ways. the global transport system is almost entirely dependent on oil—not just private passenger automobiles, but trucks, ships, diesel locomotives, and the entire passenger and freight air- line industry. High fuel prices will thus affect entire economies as travel becomes more expen- sive and manufacturers and retailers are forced to absorb higher transport costs.
Conventional industrial agriculture is also overwhelmingly dependent on oil, as modern farm machinery runs on petroleum products and oil is needed for the transport of farm inputs and outputs. oil also provides the feedstock for making pesticides. According to one study, approximately seven calories of fossil fuel energy are needed to produce each delivered calo- rie of food energy in modern industrial food systems. With the global proliferation of the industrial-chemical agriculture system, the products of that system are now also traded glob- ally, enabling regions to host human populations larger than local resources alone could sup- port. those systems of global distribution and trade also rely on oil. Within the united States, the mean distance for food transport is now estimated at 1,546 miles. High fuel prices and fuel shortages therefore translate to increasing food prices and potential food shortages.
A small but crucial portion of oil consumed globally goes into the making of plastics and chemicals. Some of the more common petrochemical building blocks of our industrial world are ethylene, propylene, and butadiene. Further processing of just these three chemicals pro- duces products as common and diverse as disinfectants, solvents, antifreezes, coolants, lubri- cants, heat transfer fluids, and of course plastics, which are used in everything from building materials to packaging, clothing, and toys. Future oil supply problems will affect the entire chain of industrial products that incorporates petrochemicals.
Economic impacts to transport, trade, manufacturing, and agriculture will in turn lead to internal social tensions within importing countries. In exporting countries the increasing value of remaining oil reserves will exacerbate rivalries between political factions vying to control this source of wealth. Increased competition between consuming nations for con- trol of export flows, and between import- ing nations and exporters over contracts and pipelines, may lead to international conflict. none of these effects is likely to be transitory. the crisis of peak oil will not be solved in months, or even years. Decades will be required to reengineer modern economies to function with a perpetually declining supply of oil.
Consider This What are some of the most important and worrisome impacts of a potential decline in the availability of oil in our modern economy?
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4. How Is the World Responding? In 1998, policy makers had virtually no awareness of peak oil as an issue. now there are peak oil groups within the u.S. Congress and the British Parliament, and individual members of government in many other countries are keenly aware of the situation. Government reports have been issued in several nations. Some cities have undertaken assessments of petroleum supply vulnerabilities and begun efforts to reduce their exposure. A few nongovernmental organizations (nGos) have been formed for the purpose of alerting government at all levels to the problem and helping develop sensible policy responses—notably, the Association for the Study of Peak oil and Gas (ASPo) and the Post Carbon Institute. And grassroots efforts in several countries have organized “transition Initiatives” wherein citizens participate in the development of local strategies to deal with the likely consequences of peak oil.
unfortunately, this response is woefully insufficient given the scale of the challenge. More- over, policies that are being undertaken are often ineffectual. Efforts to develop renewable sources of electricity are necessary to deal with climate change; however, they will do little to address the peak oil crisis, since very little of the transport sector currently relies on electric- ity that could be supplied from solar, wind, or other new electricity sources. Biofuels are the subject of increasing controversy having to do with ecological problems, the displacement of food production, and low energy efficiency; even in the best instance, they are unlikely to offset more than a small percentage of current oil consumption.
5. What Would Be an Effective Response? one way to avert or ameliorate the impacts of peak oil would be to implement a global agree- ment to proactively reduce the use of oil (effectively, a reduction in demand) ahead of actual scarcity. Setting a bold but realistic mandatory target for demand restraint would reduce price volatility, aid with preparation and planning, and reduce international competition for remaining supplies. A proposal along these lines was put forward by physicist Albert Bartlett in 1986, and a similar one by petroleum geologist Colin Campbell in 1998; Campbell’s pro- posal was the subject of the book The Oil Depletion Protocol: A Plan to Avert Oil Wars, Terror- ism and Economic Collapse. In order to enlist public support for such efforts, governments would need to devote significant resources to education campaigns. In addition, planning and public investment would be needed in transportation, agriculture, and chemicals-materials industries. For each of these there are two main strategic pathways.
Transportation
• Design communities to reduce the need for transportation (localize production and distribution of goods including food, while designing or redesigning urban areas for density and diversity);
• Promote alternatives to the private automobile and to air- and truck-based freight transport (by broadening public transport options, creating incentives for use of public transportation, and creating disincentives for automobile use). First priority should go to electrified transport options, as these are most efficient, then to alternative-fueled transport options, and finally to more-efficient petroleum-fueled transport options.
Agriculture
• Maximize local production of food in order to reduce the vulnerability implied by a fossil fuel–based food delivery system;
• Promote forms of agriculture that rely on fewer fossil fuel inputs.
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Materials and Chemicals
• Identify alternative materials from renewable sources to replace petrochemical– based materials;
• Devise ways to reduce the amount of materials consumed.
oil depletion presents a unique set of vulnerabilities and risks. If policy makers fail to under- stand these, nations will be mired in both internal economic turmoil and external conflict caused by fuel shortages. Policy makers may assume that, in addressing the dilemma of global climate change via carbon caps and trades, they would also be doing what is needed
to deal with the problem of dependence on depleting petroleum. this could be a dangerously misleading assumption.
Fossil fuels have delivered enormous economic benefits to modern societies, but we are now becoming aware of the burgeoning costs of our dependence on these fuels. Humanity’s central task for the coming decades must be the undoing of its dependence on oil, coal, and natural
gas in order to deal with the twin crises of resource depletion and climate change. It is surely fair to say that fossil fuel dependency constitutes a systemic problem of a kind and scale that no society has ever had to address before. If we are to deal with this challenge successfully, we must engage in systemic thinking that leads to sustained, bold action.
Adapted from Heinberg, R. (2012). The View From Oil’s Peak. EnErGY: overdevelopment and the Delusion of Endless Growth, Tom Butler and George Wuerthner, eds. (Healdsburg, CA: Watershed Media). Retrieved from http://energy -reality.org/wpcontent/uploads/2013/06/08_the-View-from-oils-Peak_r1_040713.pdf. Copyright (c) 2012. Reprinted by permission of The Post Carbon Institute.
Consider This What are the major challenges to achieving a reduction in oil use in the transportation, agriculture, and materials and chemicals sector described above?
Apply Your Knowledge the term “peak oil” is meant to define the moment in time when worldwide oil production will reach its peak and begin to decline. Adherents of the peak oil theory believe that most of the easy-to-exploit oil reserves have already been depleted and that what remains will be increasingly difficult and costly to extract. Critics of the theory point to earlier flawed predic- tions of an oil production peak and argue that advances in technology will make available new supplies of oil in the future. to get a sense of this debate, first visit the websites of the Post Car- bon Institute (http://www.postcarbon.org) and the Association for the Study of Peak oil and Gas (ASPo; http://www.peakoil.net/). read some of the postings and other information on this page. next, read these two articles from the Guardian newspaper (http://www.guardian .co.uk/environment/2013/jan/16/peak-oil-theories-groundless-bp and http://www.guard ian.co.uk/environment/damian-carrington-blog/2012/nov/12/iea-report-peak-oil). What are the primary points of difference between the proponents of the peak oil theory and the experts and officials cited in the two news stories? Why does the second news article say that even though the peak oil idea is misleading, we should still leave most of that oil in the ground? What is your sense of the peak oil debate? Based on this, what should American energy policy focus on in the years and decades ahead?
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SECtIon 6.4tHE FuturE oF CoAl
6.4 The Future of Coal Coal is far more abundant than oil, and yet there is a growing uncertainty over its future due to its environmental impact—especially in terms of greenhouse gas emissions. Used mainly to generate electricity, coal produces roughly twice as much carbon dioxide per unit of energy out- put as natural gas-fired power plants. In this article, David Hawkins, Daniel Lashof, and Robert Williams of the Natural Resources Defense Council (NRDC) review whether an approach known as carbon capture and storage (CCS) might allow us to continue to use coal to generate elec- tricity while reducing carbon dioxide emissions from its combustion.
The main appeal of coal is its abundance. At current rates of consumption, domestic reserves of coal could last for over 200 years. Unlike oil then, the main constraint on the future use of coal turns out to have less to do with actual reserves and more with the environmental impacts of its use. Primary among these environmental impacts are emissions of carbon dioxide (CO2 ), a consequence of burning a largely carbon-based fuel like coal in the presence of oxygen. CO2 is the primary human-generated greenhouse gas implicated in the issue of global climate change (see section 7.2), and burning coal is one of the main contributors to a buildup of CO2 in the atmosphere.
While carbon capture and storage might—if it were proven safe and actually developed—help address the CO2 pollution associated with coal use, it does almost nothing to reduce coal’s other major environmental impacts. For example, mountaintop removal coal mining literally blows the tops off of mountains and dumps them into nearby valleys to expose underground coal deposits. This and other forms of coal mining do serious damage to local air and water quality and can result in acid mine drainage and other threats to aquatic life. Burning coal produces not only CO2 but also sulfur dioxide and oxides of nitrogen that worsen regional air quality and impose enormous costs on society in the form of increased health care costs. Coal combustion also puts mercury into the atmosphere, an issue reviewed in the case history in section 1.7.
Overall, if you were to add up all of the health and environmental costs imposed on society by the extraction and combustion of coal, it could no longer be described as an inexpensive fuel. Nevertheless, because it is abundant, and because we already have hundreds of coal-fired elec- tric power plants in operation, it appears that coal will continue to contribute to our energy needs for at least another decade or more. The idea of carbon capture and storage has thus been a divisive issue in the environmental field. Some see it as the only hope for reducing carbon dioxide emissions from an inevitable use of coal. Others argue that it is little more than part of a clever marketing campaign by the coal industry to distract attention from the need to more rapidly develop new and renewable energy resources. Regardless, CCS continues to be a topic of discussion in energy policy debates, and so it is worth reviewing to gain a better understanding of how it works.
By David G. Hawkins, Daniel A. Lashof, and Robert H. Williams More than most people realize, dealing with climate change means addressing the problems posed by emissions from coal-fired power plants. unless humanity takes prompt action to strictly limit the amount of carbon dioxide (Co2) released into the atmosphere when consum- ing coal to make electricity, we have little chance of gaining control over global warming.
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Coal—the fuel that powered the Industrial revolution—is a particularly worrisome source of energy, in part because burning it produces considerably more carbon dioxide per unit of electricity generated than burning either oil or natural gas does. In addition, coal is cheap and will remain abundant long after oil and natural gas have become very scarce. With coal plenti- ful and inexpensive, its use is burgeoning in the u.S. and elsewhere and is expected to continue rising in areas with abundant coal resources. Indeed, u.S. power providers are expected to build the equivalent of nearly 280 500-megawatt, coal-fired electricity plants between 2003 and 2030. Meanwhile China is already constructing the equivalent of one large coal-fueled power station a week. over their roughly 60-year life spans, the new generating facilities in operation by 2030 could collectively introduce into the atmosphere about as much carbon dioxide as was released by all the coal burned since the dawn of the Industrial revolution.
Coal’s projected popularity is disturbing not only for those concerned about climate change but also for those worried about other aspects of the environment and about human health and safety. Coal’s market price may be low, but the true costs of its extraction, processing, and consumption are high. Coal use can lead to a range of harmful consequences, including decap- itated mountains, air pollution from acidic and toxic emissions, and water fouled with coal wastes. Extraction also endangers and can kill miners. together such effects make coal pro- duction and conversion to useful energy one of the most destructive activities on the planet.
In keeping with Scientific American’s focus on climate concerns in this issue, we will concen- trate below on methods that can help prevent Co2 generated during coal conversion from reaching the atmosphere. It goes without saying that the environmental, safety and health effects of coal production and use must be reduced as well. Fortunately, affordable techniques for addressing Co2 emissions and these other problems already exist, although the will to implement them quickly still lags significantly.
Geologic Storage Strategy the techniques that power providers could apply to keep most of the carbon dioxide they produce from entering the air are collectively called Co2 capture and storage (CCS) or geo- logic carbon sequestration. these procedures involve separating out much of the Co2 that is created when coal is converted to useful energy and transporting it to sites where it can be stored deep underground in porous media—mainly in depleted oil or gas fields or in saline formations (permeable geologic strata filled with salty water).
Implementing CCS at coal-consuming plants is imperative if the carbon dioxide concentration in the atmosphere is to be kept at an acceptable level. the 1992 united nations Framework Convention on Climate Change calls for stabilizing the atmospheric Co2 concentration at a “safe” level, but it does not specify what the maximum value should be. the current view of many scientists is that atmospheric Co2 levels must be kept below 450 parts per million by volume (ppmv) to avoid unacceptable climate changes. realization of this aggressive goal requires that the power industry start commercial-scale CCS projects within the next few years and expand them rapidly thereafter. this stabilization benchmark cannot be realized by CCS alone but can plausibly be achieved if it is combined with other eco-friendly measures, such as wide improvements in energy efficiency and much expanded use of renewable energy sources.
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Figure 6.3: Carbon capture and storage
this process involves separating out much of the Co2 created by coal-fueled power plants and transporting it to sites where it can be stored deep underground in depleted oil or gas fields or in saline formations.
the Intergovernmental Panel on Climate Change (IPCC) estimated in 2005 that it is highly probable that geologic media worldwide are capable of sequestering at least two trillion met- ric tons of Co2—more than is likely to be produced by fossil-fuel-consuming plants during the 21st century. Society will want to be sure, however, that potential sequestration sites are evaluated carefully for their ability to retain Co2 before they are allowed to operate. two classes of risks are of concern: sudden escape and gradual leakage.
Technology Choices Design studies indicate that existing power generation technologies could capture from 85 to 95 percent of the carbon in coal as Co2, with the rest released to the atmosphere.
the coal conversion technologies that come to dominate will be those that can meet the objectives of climate change mitigation at the least cost. Fundamentally different approaches to CCS would be pursued for power plants using the conventional pulverized-coal steam cycle
Unmineable coal beds
Depleted oil field
Saline formation
Depleted gas field
CO2
CO2 CO2
CO2
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and the newer integrated gasification combined cycle (IGCC). Although today’s coal IGCC power (with Co2 venting) is slightly more expensive than coal steam-electric power, it looks like IGCC is the most effective and least expensive option for CCS.
In an IGCC system coal is not burned but rather partially oxidized (reacted with limited quan- tities of oxygen from an air separation plant, and with steam) at high pressure in a gasifier. the product of gasification is so-called synthesis gas, or syngas, which is composed mostly of carbon monoxide and hydrogen, undiluted with nitrogen. In current practice, IGCC opera- tions remove most conventional pollutants from the syngas and then burn it to turn both gas and steam turbine-generators in what is called a combined cycle.
In an IGCC plant designed to capture Co2, the syngas exiting the gasifier, after being cooled and cleaned of particles, would be reacted with steam to produce a gaseous mixture made up mainly of carbon dioxide and hydrogen. the Co2 would then be extracted, dried, compressed and transported to a storage site. the remaining hydrogen-rich gas would be burned in a combined cycle plant to generate power.
Analyses indicate that carbon dioxide capture at IGCC plants consuming high-quality bitu- minous coals would entail significantly smaller energy and cost penalties and lower total generation costs than what could be achieved in conventional coal plants that captured and stored Co2. Gasification systems recover Co2 from a gaseous stream at high concentration and pressure, a feature that makes the process much easier than it would be in conventional steam facilities.
overall, pursuing CCS for coal power facilities requires the consumption of more coal to gen- erate a kilowatt-hour of electricity than when Co2 is vented—about 30 percent extra in the case of coal steam-electric plants and less than 20 percent more for IGCC plants. But overall coal use would not necessarily increase, because the higher price of coal-based electricity resulting from adding CCS equipment would dampen demand for coal-based electricity, mak- ing renewable energy sources and energy-efficient products more desirable to consumers.
the cost of CCS will depend on the type of power plant, the distance to the storage site, the properties of the storage reservoir and the availability of opportunities (such as enhanced oil recovery) for selling the captured Co2. A recent study co-authored by one of us (Williams) estimated the incremental electric generation costs of two alternative CCS options for coal IGCC plants under typical production, transport and storage conditions. For Co2 sequestra- tion in a saline formation 100 kilometers from a power plant, the study calculated that the incremental cost of CCS would be 1.9 cents per kilowatt-hour (beyond the generation cost of 4.7 cents per kilowatt-hour for a coal IGCC plant that vents Co2—a 40 percent premium). For CCS pursued in conjunction with enhanced oil recovery at a distance of 100 kilometers from the conversion plant, the analysis finds no increase in net generation cost would occur as long as the oil price is at least $35 per barrel, which is much lower than current prices.
CCS Now or Later? Many electricity producers in the industrial world recognize that environmental concerns will at some point force them to implement CCS if they are to continue to employ coal. But rather than building plants that actually capture and store carbon dioxide, most plan to con- struct conventional steam facilities they claim will be “Co2 capture ready”—convertible when CCS is mandated.
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Yet delaying CCS at coal power plants until economy-wide carbon dioxide control costs are greater than CCS costs is shortsighted. For several reasons, the coal and power industries and society would ultimately benefit if deployment of plants fitted with CCS equipment were begun now.
First, the fastest way to reduce CCS costs is via “learning by doing”—the accumulation of experience in building and running such plants. the faster the understanding is accumulated, the quicker the know-how with the new technology will grow, and the more rapidly the costs will drop.
Second, installing CCS equipment as soon as possible should save money in the long run. Most power stations currently under construction will still be operating decades from now, when it is likely that CCS efforts will be obligatory. retrofitting generating facilities for CCS is inherently more expensive than deploying CCS in new plants. Moreover, in the absence of Co2 emission limits, familiar conventional coal steam-electric technologies will tend to be favored for most new plant construction over newer gasification technologies, for which CCS is more cost-effective.
Finally, rapid implementation would allow for continued use of fossil fuels in the near term (until more environmentally friendly sources become prevalent) without pushing atmo- spheric carbon dioxide beyond tolerable levels. our studies indicate that it is feasible to stabi- lize atmospheric Co2 levels at 450 ppmv over the next half a century if coal-based energy is completely decarbonized and other measures are implemented.
our calculations indicate that the costs of CCS deployment would be manageable as well. using conservative assumptions— such as that technology will not improve over time—we estimate that the present worth of the cost of capturing and stor- ing all Co2 produced by coal-based elec- tricity generation plants during the next 200 years will be $1.8 trillion (in 2002 dollars). that might seem like a high price tag, but it is equivalent to just 0.07 per- cent of the current value of gross world product over the same interval. thus, it is plausible that a rapid decarbonization path for coal is both physically and economically feasible, although detailed regional analyses are needed to confirm this conclusion.
Policy Push Is Needed those good reasons for commencing concerted CCS efforts soon will probably not move the industry unless it is also prodded by new public policies. Such initiatives would be part of a broader drive to control carbon dioxide emissions from all sources.
In the u.S., a national program to limit Co2 emissions must be enacted soon to introduce the government regulations and market incentives necessary to shift investment to the least- polluting energy technologies promptly and on a wide scale. leaders in the American business and policy communities increasingly agree that quantifiable and enforceable restrictions on
Consider This What are the main arguments for moving ahead aggressively with carbon capture and storage initiatives now versus a go- slow approach that focuses on building coal plants that are “Co2 capture ready?”
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global warming emissions are imperative and inevitable. to ensure that power companies put into practice the reductions in a cost-effective fashion, a market for trading Co2 emissions credits should be created—one similar to that for the sulfur emissions that cause acid rain. In such a plan, organizations that intend to exceed designated emission limits may buy credits from others that are able to stay below these values.
Even if a carbon dioxide cap-and-trade program were enacted in the next few years the eco- nomic value of Co2 emissions reduction may not be enough initially to convince power pro- viders to invest in power systems with CCS. to avoid the construction of another generation of conventional coal plants, it is essential that the federal government establish incentives that promote CCS.
If the surge of conventional coal-fired power plants currently on drawing boards is built as planned, atmospheric carbon dioxide levels will almost certainly exceed 450 ppmv. We can meet global energy needs while still stabilizing Co2 at 450 ppmv, however, through a combi- nation of improved efficiency in energy use, greater reliance on renewable energy resources and, for the new coal investments that are made, the installation of Co2 capture and geologic storage technologies. Even though there is no such thing as “clean coal,” more can and must be done to reduce the dangers and environmental degradations associated with coal production and use. An integrated low-carbon energy strategy that incorporates Co2 capture and storage can reconcile substantial use of coal in the coming decades with the imperative to prevent catastrophic changes to the earth’s climate.
Adapted from Hawkins, D. G., Lashof, D. A., and Williams, R. H. (2006, September). What to Do About Coal? Scien- tific American, 68–75. Reproduced with permission. Copyright © 2006 Scientific American, Inc. All rights reserved. Retrieved from http://www.scientificamerican.com/article.cfm?id=what-to-do-about-coal-2006
Apply Your Knowledge Faced with criticism of its environmental record, the American coal industry has launched an all-out, multimillion-dollar public relations campaign around the idea of clean coal. the term “clean coal” is generally used to describe techniques that reduce the pollution associated with burning coal. the best-known example of this is carbon capture and storage, described in this section. However, critics argue that clean coal is nothing more than a clever, and mis- leading, marketing solution. they suggest that even with the use of CCS technologies, coal comes nowhere close to being a “clean” source of energy. Start by reviewing the website of the American Coalition for Clean Coal Electricity (ACCCE; http://www.cleancoalusa.org/). What evidence and arguments does this group put forward to support their claim of clean coal electricity? next, read three short articles challenging the whole basis of the clean coal concept (http://e360.yale.edu/feature/the_myth_of_clean_coal/2014/, http://www.popular mechanics.com/science/energy/coal-oil-gas/4339171, and http://www.time.com/time /health/article/0,8599,1870599,00.html). Why do the authors of these articles take issue with claims made by clean coal groups? Even if CCS technologies were fully developed and widely adopted, why might these authors still argue that coal is not clean? What other barri- ers and challenges do they raise regarding the feasibility of widespread implementation of CCS technologies? Based on your review of this information, should the coal industry be allowed to continue to make clean coal claims?
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SECtIon 6.5Unconventional Fossil FUels—shale Gas
6.5 Unconventional Fossil Fuels—Shale Gas Natural gas currently meets roughly one fourth of America’s energy requirements and is espe- cially important as a home heating fuel and for electricity generation. Concerns over global climate change have made natural gas even more important in the electric power sector since it emits roughly half the greenhouse gases per unit of electricity generated as does coal. However, following the resource pyramid concept discussed in section 6.2, many of the highly concen- trated and easily accessible natural gas deposits in the United States have already been heav- ily exploited, so the conventional natural gas resource base is dwindling. The combination of declining conventional gas deposits, growing demand for gas, higher prices, and technological breakthroughs in drilling and extraction of gas have opened up the possibility of exploiting large quantities of unconventional natural gas further down the resource pyramid.
This article by Bryan Walsh of time Magazine focuses on the challenges and opportunities of exploiting unconventional natural gas deposits such as the Marcellus shale formation. These deposits could hold enough gas to meet U.S. demand for years or decades. However, in order to extract gas from shale deposits, energy companies are forced to use a technique known as hydraulic fracturing (sometimes referred to as hydrofracturing, hydro-fracking, or just frack- ing). In hydraulic fracturing, hundreds of thousands of gallons of water mixed with sand and chemicals are pumped thousands of feet below the surface under extremely high pressure to break up the shale rock and release the gas present in the deposit. This has led to concerns over both where that water will come from and what it contains when it flows back to the surface. This wastewater or flowback water includes high concentrations of salts and in some cases radioac- tive materials carried up from deep below the Earth’s surface. Because hydraulic fracturing is such a new approach to energy development, there is concern that regulations currently on the books are not adequate to address some of the issues associated with its use.
This article also makes clear just how voracious and unending our need for fossil fuels currently is. The great lengths that energy companies now go through to extract energy from unconven- tional sources, such as shale deposits, is proof of this. And while natural gas may be cleaner than coal in terms of carbon dioxide emissions, combustion of this fuel still contributes to global cli- mate change. All of this raises important questions about whether we can continue to maintain fossil fuels as the centerpiece of our energy economy, or whether a rapid switch to less polluting forms of energy should be an urgent priority. Those issues will be the focus of discussion in Chap- ters 7 (Climate Change) and 8 (Renewable Energy).
By Bryan Walsh For more than a decade, Bonnie Burnett and her husband truman have owned a second home in the hilly farmland of Bradford County, in northeastern Pennsylvania. It was a getaway for the Burnetts (who live three hours to the south, in Stroudsburg), a place to take their grand- children for a swim in the wooded pond that lies just a few steps from their front door. “It used to be heaven here,” says Bonnie. “We were going to move here to live.”
the Burnetts say their plans changed when a natural gas drilling operation on an adjacent property started less than 400 ft. (122 m) from their house. It was one of thousands of wells that have been drilled in Pennsylvania as part of a booming natural gas rush. In June 2009, when the Burnetts were home in Stroudsburg, tens of thousands of gallons of drilling water that had been stored on the well pad spilled, leaking downhill and into the Burnetts’ trees and pond. truman says that spill ruined a 50-ft. (15 m) swath of forest and affected their water.
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the pond seems lifeless, and the bass and perch that the Burnetts once fished with their grandchildren are gone. Even after the accident, the well is still running. the Burnetts can hear the hum of a gas compressor running 24 hours a day. “Did it ruin my life?” asks a tearful Bonnie. “I’d have to say yes.”
Dave DeCristo of nearby Canton, Pa., can see wells from his home too, but that’s where any similarity with the Burnetts ends. DeCristo moved to this rural community to work as a plumber before he launched a gas station and a fuel-support outfit. He did well, but his busi- nesses really took off in 2008, when drilling companies eager for the region’s natural gas began setting up shop, and he’s added dozens of employees. In addition, DeCristo—like other landowners around the region—has sold a gas company the right to drill on his land. there’s a well not far from his front door. “I could never dream I was going to be able to grow this big,” he says. “I’ve been a blessed person because of this.”
until recently, natural gas was the forgotten stepsister of fuels. It provides about a quarter of u.S. electricity and heats over 60 million American homes, but it’s always been limited—more expensive than dirty coal, dirtier than nuclear or renewables. Much of Europe depends on gas for heating and some electricity—but the bulk of the supply comes from russia, which hasn’t hesitated to use energy as a form of political blackmail. the fuels of the future were going to be solar, wind and nuclear. “the history of natural gas in the u.S. has been a roller-coaster ride,” says tony Meggs, a co-chair of a 2010 Massachusetts Institute of technology gas study. “It’s been up and down and up and down.”
natural gas is up now—way up—and it’s changing how we think about energy throughout the world. If its boosters are to be believed, gas will change geopolitics, trimming the power of states in the troubled Middle East by reducing the demand for their oil; save the lives of thou- sands of people who would otherwise die from mining coal or breathing its filthy residue; and make it a little easier to handle the challenges of climate change—all thanks to vast new onshore deposits of what is called shale gas. using new drilling methods pioneered by a texas wildcatter, companies have been able to tap enormous quantities of gas from shale, leading to rock-bottom prices for natural gas even as oil soars. In a single year, the usually sober u.S. Energy Information Administration more than doubled its estimates of recoverable domestic shale-gas resources to 827 trillion cu. ft. (23 trillion cu m), more than 34 times the amount of gas the u.S. uses in a year. together with supplies from conventional gas sources, the u.S. may now have enough gas to last a century at current consumption rates. (By comparison, the u.S. has less than nine years of oil reserves.)
nor is the u.S. alone. Britain, India, China and countries in Eastern Europe have potential shale plays as well, while Australia, having invested in huge infrastructure projects, has started sending fleets of ships with liquefied natural gas around the world.
over all this loom three factors: booming demand for energy as nations such as China and India industrialize; the accident at the Fukushima nuclear plant in Japan, which has dimmed prospects for a renaissance of nuclear power; and the turmoil in the oil-rich Middle East. taken together, they have opened space for gas as a relatively clean, relatively cheap fuel that can help fill the world’s needs during the transition to a truly green economy. (As important as renewable energy is, it will likely take years for green power to shoulder the electricity load.) Although gas isn’t used for transport, boosters like texas tycoon t. Boone Pickens think if heavy-duty vehicles were fueled with natural gas, the u.S. would be able to cut imports of
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oil. u.S. utilities worried about meeting regulations on carbon and air pollution are switching from dirty coal to gas as a power source. In a speech on March 30, President Barack obama hailed natural gas as part of the solution to reducing America’s oil addiction. “the potential for natural gas is enormous,” he said.
They Weren’t Ready for This But there’s a catch. As shale-gas drilling has ramped up, it’s been met with a growing environ- mental backlash. there are complaints about spills and air pollution from closely clustered wells and fears of wastewater contamination from the hydraulic fracturing process—also known as fracking—that is used to tap shale-gas resources. In the u.S., the gas industry is exempt from many federal regulations, leaving most oversight to state governments that have sometimes been hard-pressed to keep up with the rapid growth of drilling. the investiga- tive news site ProPublica has found over 1,000 reports of water contamination near drilling sites. new York State—spurred by fears about the possible impact of the industry on new York City’s watershed—has put hydraulic fracturing on hold for further study, while some members of Congress are looking to tighten regulation of drilling. “We were not ready for this,” says John Quigley, former head of Pennsylvania’s department of conservation and natu- ral resources. “We weren’t ready for the technology or the scale or the pace.”
And that’s what makes this new energy revolution—because that’s what it is—so complex. the richest shale-gas play and potentially the second biggest natural gas field in the world is called the Marcellus, and its heart runs straight through parts of Pennsylvania and new York. this drilling isn’t taking place in the Gulf of Mexico, the Saudi deserts or lightly popu- lated western Canada. It’s happening right in the backyard of the u.S. northeast, a densely populated place accustomed to consuming fossil fuels, not producing them. But if the global appetite for gas and oil keeps growing, rural Pennsylvania won’t be the last unlikely place we’ll drill. Because for all our fears of running out of oil, we should be able to find more than enough fuel to keep the global economy humming—provided we’re willing to drill in deeper, darker, more dangerous or more crowded places. the Arctic, the ultra-deep ocean off Bra- zil and new York City’s watershed all could go under the drill as we enter what the writer Michael Klare has called the Era of Extreme Energy. the power will keep flowing—but with environmental and even social costs we can’t yet predict.
It wasn’t news to fossil-fuel experts that the Marcellus Shale—a 400 million-year-old nar- row band of black rock that lies thousands of feet deep—could contain gas. Shallow natural gas wells have been drilled in the northeast for decades. But shale like that of the Marcellus is made up of deep, hard rock, and it does not surrender its gas easily. Shale wasn’t worth the trouble—until a veteran wildcatter named George Mitchell began experimenting with the Barnett Shale in texas in the 1980s. Mitchell found that a mix of horizontal well drilling and hydraulic fracturing—more on that later—could allow him to pry gas from the shale. “It was lore in the gas industry that you would hurt a well by putting water down it,” says terry Engelder, a geoscientist at Penn State university. “these guys discovered that the more water they used, the better.”
Engelder should know; he played a key role in the discovery of the Marcellus Shale. At the beginning of the last decade, a texas-based company called range resources began experi- menting on Marcellus wells in western Pennsylvania. the company had little more than expen- sive holes to show for it until it began tweaking Mitchell’s method. By August 2007, range had
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a winner, even as Engelder, a gas-shale expert, began to realize just how huge the Marcellus play could be. During a December 2007 conference call with investors, Engelder estimated the recoverable amount of natural gas in the Marcellus at 50 trillion cu. ft. (1.4 trillion cu m). Estimates now range up to 10 times as high, which would provide the energy equivalent of 86 billion barrels of oil. “I remember thinking, Merry Christmas, America,” Engelder says now. “It was absolutely an amazing thing.”
the agents of drilling companies had already begun moving into Marcellus territory, snap- ping up gas leases. that’s not unusual in Pennsylvania—most farmers and other large land- holders have leased the gas rights to their land for decades, often for little more than a few dollars an acre (0.4 hectare). But not much actual drilling was ever done. (landholders are paid an up-front bonus per acre for a lease, plus some percentage of the value of any pro- duced gas as a royalty.) When word got out that the Marcellus was for real, the price for leases skyrocketed—rising to $5,000 an acre by the summer of 2008, according to Engelder—and dozens of gas companies jostled for territory. once land was leased, the drilling rigs arrived, clustering in rural areas of southwestern and northeastern Pennsylvania. More than 2,400 Marcellus wells were drilled from 2006 to the end of 2010 in the state, and some 300 were drilled before March 10 of this year. “It’s like a treadmill. Companies have to keep drilling wells and adding new ones to their inventory,” says tim Considine, an energy economist at the university of Wyoming. “that’s a lot of activity that adds up.”
Considine co-authored an industry-sponsored study in early 2010 that estimated that Mar- cellus drilling would create or support 88,000 jobs that year and more than 100,000 in 2011, plus billions of dollars in economic value for the state. those numbers are debatable, but it’s impossible to miss the buzz of economic activity in drilling regions. relatively few of those jobs directly involve drilling and fracking—most of that work goes to roughnecks with texas or oklahoma license plates on their pickups—but there are work and wages for local truck drivers, subcontractors, waiters and bartenders. rural Bradford County has long been one of Pennsylvania’s poorer areas, but last year the county led the state in job creation. Gregg Mur- relle manages the riverstone Inn and Comfort Inn in towanda, the Bradford County seat, and his hotels are fully booked for weeks on end, full of gas workers on 14-day stints. He’s building another unit, and he estimates he’s hired an additional 20 employees since the drillers moved in, with another 15 to 20 needed for the new hotel. “It’s just been wonderful that these busi- nesses have come into the area,” says Murrelle, who has leased the land around his properties for drilling. “We’re not being impacted by the recession at all.”
For a state that is billions of dollars in debt, it’s hard to resist the economic potential of drill- ing, drilling and more drilling—not that many politicians are trying. A just-released Penn State study found that sales-tax revenues from Pennsylvania counties with at least 150 Mar- cellus wells experienced an 11.36% increase from 2007 to 2010, while counties without wells experienced sharp declines. new republican governor tom Corbett—who has received hun- dreds of thousands of dollars in contributions from the gas industry over his career—sees the Marcellus as the key to Pennsylvania’s economic rebirth, and he’s already begun removing some limits on drilling. “the Marcellus is a resource, a source of potential wealth, the founda- tion of a new economy,” said Corbett last month in his maiden budget address. “let’s make Pennsylvania the texas of the natural gas boom.”
Which, as some very unhappy Pennsylvanians see it, is exactly the problem.
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The Flowback It wasn’t the fact that the gas company used the family driveway to bring hundreds of trucks to the well being drilled on their property that annoyed the Johnsons so much. nor was it that the multi-acre well pad was just a few hundred feet from their back door, even though the Johnsons had leased hundreds of acres on their dairy farm outside Wellsboro. But when their cows last summer ended up drinking from a suspected leak in a drilling wastewater pond— slurping up water contaminated with the radioactive element strontium—that was too much. You don’t mess with a farmer’s livestock, and dozens of the Johnsons’ cows had to be kept in quarantine. “We wished the gas company had never come around here,” says 75-year-old Don Johnson, who has lived in the area his entire life. “they affected the water, and without water you can’t farm here and you can’t live here.”
It’s water that’s at the heart of the environmental impact of shale-gas drilling. to understand why, you need to understand how horizontal well drilling and hydraulic fracturing work. the name isn’t accidental—as much as 5 million gal. (19 million l) of water is used in a typical hydraulically fractured (or hydrofracked) well in the Marcellus. First a drilling rig will dig a vertical hole several thousand feet deep, gradually bending until the concrete-encased well reaches the shale layer. After burrowing horizontally for as much as a mile (1.6 km), the drill- ers lower a perforating gun down to the end of the well. that gun fires off explosions under- ground that pierce the concrete and open up microfractures in the shale. the drillers then shoot millions of gallons of highly pressurized water, mixed with sand and small amounts of additives known as fracking chemicals, down the well, widening the shale fractures. natural pressure forces the liquids back up the well, producing what’s known as flowback, and the gas rushes from the fractures into the pipe. the grains of sand included in the fracking fluid keep the shale cracks open—like stents in a clogged blood vessel—while the well produces gas for years, along with a steadily decreasing amount of wastewater from deep inside the shale.
Many environmental activists worry that fracking fluid could somehow contaminate nearby groundwater. Even though fracking chemicals make up only perhaps 0.5% of the overall drill- ing fluid, in a 5 million–gal. (19 million l) job, that would still amount to some 25,000 gal. (95,000 l). It’s not always clear what those chemicals are, because the industry isn’t required to release the precise makeup of its fracking formulas—and drilling-service companies like Halliburton have been reluctant to reveal the information. (It’s not for nothing that a provi- sion in the 2005 energy bill that prevents the Environmental Protection Agency from regu- lating hydraulic fracturing has been nicknamed the Halliburton loophole.) Gas companies compare fracking additives to household chemicals, but some environmentalists and scien- tists believe the formulas can contain toxic ingredients. When the fracking fluid mixes with the shale, it may also become contaminated with radioactivity—the Marcellus is slightly radioactive—while growing increasingly brackish. “You bring everything the fluid encounters down there back to the surface along with the gas,” Michel Boufadel, an environmental engi- neer at temple university, told tIME last year.
the chance that fracking fluid could directly escape through the deep fractures created by the process and contaminate groundwater appears remote. the Marcellus Shale is separated from aquifers by thousands of feet of rock, much of it impermeable, and the gas industry argues that there has never been a proven case of water contamination through hydraulic fracturing. “I don’t think it’s scientifically plausible to suggest that could happen,” says Don Siegel, a hydrogeologist at Syracuse university. In a 2009 study, the Ground Water Protection Council, a consortium that includes industry and state regulators, reported that the chance
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SECtIon 6.5Unconventional Fossil FUels—shale Gas
of aquifer contamination was extremely low, echoing the results of a 2004 EPA review of hydraulic fracturing. But that EPA report has been criticized, and the science is open enough that the agency is beginning a comprehensive new study of the relationship between hydrau- lic fracturing and drinking water.
of greater concern is what may be happening closer to the surface. Wells need to be properly cemented to prevent any gas or fluid from escaping before it’s collected. Cementing is one of the trickiest parts of drilling—a bad cement job helped lead to the Deepwater Horizon blowout last year—and it can and does fail over time. that seems to be what happened in the northeastern Pennsylvania town of Dimock, where the state government has said poor cementing around well casings by the drilling company Cabot allowed methane to contami- nate the water wells of 19 families. Methane isn’t dangerous to drink, but in high enough concentrations it can cause water to burn and even explode—which is exactly what happened to one Dimock family’s well in 2009. (Cabot has denied that it caused the methane contami- nation, which the company claimed was naturally occurring, but it did offer the affected resi- dents compensation.) “We were never forewarned about this risk,” says Craig Sautner, one of 14 affected Dimock residents still suing Cabot. “I worry that this took years off our lives.”
Beyond well problems, there’s the threat of spills like those that struck the Burnetts and the Johnsons. the gas industry says such accidents are rare. “We drill 35,000 wells a year, and 95% are fractured,” says lee Fuller, executive director of Energy in Depth, a gas trade group. “We need to put this in a context that reflects all the successes as well as the failures.” Still, in 2010 the Pennsylvania department of environmental protection issued 1,218 violations, out of 1,944 inspected Marcellus wells, for offenses ranging from littering to spills on drill sites. Wells have blown out, and explosions from methane contam- ination have destroyed homes. Shale- gas drilling is an industrial process, and the more wells that are drilled, the more often something will go wrong— and in a populated state like Pennsyl- vania, those accidents will be felt.
Even if everything goes right, hydrau- lic fracturing can produce over 1 mil- lion gal. (3.8 million l) of toxic, briny wastewater over the lifetime of an individual well. In western states like texas, companies can store the waste- water in deep underground control wells, but Pennsylvania’s geology makes that difficult. As a result, drillers have had to ship much of their waste- water to municipal treatment plants—and as a recent new York Times investigation showed, those plants are often incapable of screening all drilling-waste contaminants. Although Penn- sylvania has begun to tighten treatment regulations and gas companies are recycling increas- ing amounts of wastewater—reusing it in additional frack jobs—the problem is still one of the biggest challenges in drilling. “there are only a few thousand wells now, but there will be
Mark Thiessen/National Geographic Creative
Some residents living near natural gas drilling operations have had their drinking water supplies contaminated. This woman ignites the natural gas polluting her tap water.
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SECtIon 6.5Unconventional Fossil FUels—shale Gas
far more,” says Anthony Ingraffea, a structural engineer at Cornell university. “What will life be like when there are 100,000 wells here?”
that’s the fear of many Pennsylvania residents. It’s not just the worries about what might be happening to their water; it’s also what they know is happening to their communities. trucks crowd country roads, ferrying drilling fluid and equipment to and from wells. Jobs are
up, but some businesses have suffered as employees have fled for higher-paying jobs in the gas industry. As rig workers have snapped up every available room in tiny towns, rents have skyrocketed, punishing low-income families who don’t own their homes. those who had moved to the area for a quiet Pennsylvania— and those who’ve valued that peace for generations—feel betrayed. “I think it’s been a good thing overall,” says John Sullivan, a commissioner for Bradford County. “But I just wish we could keep the economic benefit and minimize everything else.”
The Cleaner Fuel Good luck with that. Make no mistake: in a post-Fukushima world, the u.S. will use this gas. It’s important to cast the environmental controversies surrounding shale drilling against the backdrop of the fossil fuel that, if all goes well, gas should help displace: coal. From mountain- top-removal mining to its impact on climate change, cheap coal is toxic to the human race. thousands die in coal mines annually around the world; in the u.S. alone, air pollution from coal combustion leads to thousands of premature deaths a year. natural gas power plants, by contrast, emit far fewer air pollutants. natural gas’s benefit over coal when it comes to climate change is less clear-cut, but it’s there, and gas can also coexist with renewable energy, providing inexpensive backup for wind and solar. “natural gas could be crucial to integrating renewables into the power grid,” says ralph Cavanagh, a co-director of the natural resources Defense Council’s energy program.
Still, Cavanagh has a warning: “Industry can blow this if it doesn’t meet the public’s environ- mental expectations.” those expectations will almost certainly include tougher regulations. In the u.S., that can be done, starting at the federal level, by giving the EPA the power to do a life- cycle analysis of hydraulic fracturing, looking at the cumulative impact of wide-scale drilling on water supplies. representative Maurice Hinchey of new York and Senator robert Casey Jr. of Pennsylvania have submitted commonsense pieces of legislation that would require indus- try to disclose the identities of chemicals used in fracking jobs. the bulk of the oversight may still be done by states, but governors will need to take care that drilling doesn’t outpace regulators, as happened in Pennsylvania. the best gas players can keep improving their rates of recycling wastewater—Chesapeake Energy says it has a 100% recycling rate—while mak- ing use of new technologies like those offered by the utah-based firm Purestream, which can
Consider This Given the potential for hydraulic fracturing to disturb drinking water supplies, how might scientists design an experiment to test the safety of this technology? What more could regulators and public health officials do to ensure the protection of public water supplies?
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SECtIon 6.5Unconventional Fossil FUels—shale Gas
evaporate and clean wastewater at the wellhead. Areas like the new York City watershed that are too valuable should be kept off-limits. “the gas is out there, and it can be accessed,” says Dean oskvig, president and CEo of Black & Veatch’s energy business. “But we do need to solve the environmental issues surrounding that extraction.”
If that can be done right, shale gas really could change the way we use energy for the better. But even if it does, the industry will still fundamentally remake parts of the u.S., and of the world, in ways we won’t always like. But that’s the price of extreme energy, and it’s one we’ll continue to pay until we can curb our hunger for fossil fuels or find a cheap, reliable and clean alternative to them.
For some people, though, the price may simply be too high. Cindy Copp’s family had lived in northeastern Pennsylvania’s tioga County for five generations, and after selling her home in town recently, she’d planned to open an organic farm. But as the quiet 50-year-old learned more about what drilling might do to the land—and as the gas boom made her hometown unrecognizable—she surrendered. “I tried to start my community, but the community is frac- tured,” she says, her eyes welling. “I don’t see a future here.”
Instead, Copp is moving to a rural commune near Hudson, n.Y. there’s no shale-gas drilling there—yet.
Adapted from Walsh, B. (2011, March 31). Could Shale Gas Power the World? time Magazine, © Copyright TIME INC. Reprinted by permission.TIME is a registered trademark of Time Inc. All rights reserved.
Apply Your Knowledge one of the most contentious debates over whether to allow hydraulic fracturing of shale gas deposits is occurring in new York State. on one side of the debate is the oil and gas industry who argues that hydraulic fracturing has been proven safe in other parts of the country and that exploiting shale gas deposits could boost upstate new York’s economy. on the other side of the debate are community groups and residents worried that large-scale gas development could contaminate water supplies and spoil the local environment. In addition to local groups, government officials in new York City, hundreds of miles from where hydraulic fracturing will take place, are also opposed to large-scale gas projects. this is because many of the reservoirs that supply new York City with its drinking water are located in upstate regions where shale gas deposits are also found. So far, the anti-drilling argument is winning the policy battle as new York has a temporary moratorium on the use of hydraulic fracturing in the state.
For this assignment, start by visiting the website of America’s natural Gas Alliance (AnGA; http://www.anga.us/). In particular, look at some of the content under “Issues & Policy.” next, view this 30-minute film on Shale Gas and America’s Future (http://www.shalegasfuture .com/) produced by an organization known as American Clean Skies Foundation (ACSF). What arguments are being made for expanded development of shale gas resources? Do you think the information on these pages is reliable given the financial interests of the groups backing them?
(continued)
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SECtIon 6.6case history—the GUlF oF Mexico Deep Water horizon oil spill
6.6 Case History—The Gulf of Mexico Deep Water Horizon Oil Spill
The Gulf of Mexico oil spill of 2010 was by far the worst accidental oil spill in American history. Yet, as this article by Leslie Kaufman of the new York times indicates, scientists are only begin- ning to scratch the surface in their understanding of the impacts of this disaster. Some of the worst predictions of what would happen appear to have not materialized, whereas other prob- lems that were not predicted are generating concern. Because developing an understanding of the environmental impacts of this disaster using the scientific method requires time to observe, test, analyze, and compare information, it could be years or even decades before the full effects of the Gulf spill are understood.
One area of focus is the impact of the oil spill on marine and bird life. Estimating the number of fish, marine mammals, and birds killed as a result of the spill is challenging for at least two reasons. First, only a fraction of these dead animals wash up on beaches where they can be tal- lied and studied. Second, there could be multiple causes of death, and detecting a link between mortality and the oil spill is not always clear-cut.
A second area of study is determining the fate of nearly 5 million barrels of oil and 200,000 tons of methane gas that escaped from the well during the crisis. Some scientists researching this question have been surprised to find that naturally occurring bacteria have actually consumed large amounts of the oil and gas that escaped. While this was considered a positive finding, other researchers have found that after consuming the oil and gas, these bacteria died and sank to the bottom of the Gulf where they have covered and suffocated bottom-dwelling organisms essential to the Gulf ’s food chain.
Apply Your Knowledge (continued) next, visit the following three websites:
• new Yorkers Against Fracking: http://nyagainstfracking.org/ • riverkeeper: http://www.riverkeeper.org/blog/fracking/ • no Fracking Anytime: http://nofracking.com/
What arguments are being made by these groups against allowing hydraulic fracturing and gas development in upstate new York? Are these sources any more or less reliable than the ones listed above? Why or why not?
lastly, review these three news articles on the links between hydraulic fracturing and water qual- ity in new York specifically (http://www.propublica.org/article/state-fracking-rules-could -allow-drilling-near-new-york-city-water-supply-t, http://www.propublica.org/article/epa -sees-risks-to-water-workers-in-new-york-fracking-rules, and http://www.nytimes.com /2013/01/03/nyregion/hydrofracking-safe-says-ny-health-dept-analysis.html). Why is the debate over hydraulic fracturing and water quality and safety so confusing? Why isn’t it easier for scientists to determine in a definitive way whether fracking is safe or not? If you were involved in settling the hydraulic fracturing debate in new York, for which side would you argue? Why?
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SECtIon 6.6case history—the GUlF oF Mexico Deep Water horizon oil spill
A third area of research has been the impact of the almost 2 million gallons of dispersants (a chemical used to break up or disperse concentrations of organic material such as oil) poured into the Gulf of Mexico at the time of the disaster. Because the dispersants contain toxins, there is concern that these could enter the marine food chain and have ecological and human health impacts. So far there is little evidence to show this, but studying such cause-effect relationships can be very complex and take time. Overall, the entire Gulf oil spill represents something of a giant experiment. Scientists studying the disaster have their hands full separating what might be caused by natural factors from what might be caused by the spill. In the end the hope is that their work can help us better understand how to prepare for and respond to future disasters of this sort.
By Leslie Kaufman In the year since the wellhead beneath the Deepwater Horizon rig began spewing rust- colored crude into the northern Gulf of Mexico, scientists have been working frantically to figure out what environmental harm really came of the largest oil spill in American history.
What has emerged in studies so far is not a final tally of damage, but a new window on the complexities of the gulf, and the vulnerabilities and capacities of biological systems in the face of environmental insults. there is no doubt that gulf water, wildlife and wetlands sustained injury when, beginning on April 20 last year [2010], some 4.9 million barrels of oil and 1.84 million gallons of dispersants poured into the waters off louisiana. But the ecosystem was not passive in the face of this assault. the gulf, which expe- riences a natural seepage of millions of gallons of oil a year, had the innate capacity to digest some of crude and the methane gas mixed with it. Almost as soon as the well was capped, the deep became cleaner to the eye. By the
same token, dozens of miles of marsh still remain blackened by heavy oil, government crews are still grooming away tar balls that wash up ceaselessly on beaches and traces of the disper- sants are still found floating in the currents.
Biologists are nervously monitoring as yet unexplained dolphin strandings this year, trying to come up with a realistic count of birds and mammals killed during the spill and working to understand what happens when the gulf floor is covered with the remains of oil-eating bacteria. “It is really kind of hard to get a grasp of the big picture, and it is not for a lack of trying,” said Christopher reddy, a senior scientist at the Woods Hole oceanographic Institu- tion who studies long-term consequences of oil spills. “Hundreds of scientists are working day and night trying to carve out a piece of that giant puzzle, but it is an entire region and it is complicated.”
AP Photo/Gerald Herbert
A coastal zone director pulls an oil-covered pelican from Barataria Bay in Louisiana shortly after the Deep Water Horizon oil spill.
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SECtIon 6.6case history—the GUlF oF Mexico Deep Water horizon oil spill
How the regional ecosystem has responded, its strengths and weaknesses, will keep scien- tists busy analyzing data for years and help them in understanding the effects of environmen- tal disasters.
An Army in Hot Pursuit After an oil spill, the government is responsible for toting up the ecological damages in some- thing called a Natural Resource Damage Assessment. the document, which requires bat- talions of researchers, makes the case for damages that the companies responsible for the spill should pay to restore the ecosystem to its pre-spill health. the companies hire their own teams of assessors, who might paint a very different picture. the two sides settle or go to court.
At of the end of January [2011], the government said its scientists alone had taken 35,000 images, walked more than 4,000 miles of shoreline, and culled more than 40,000 samples of water, sediment, and tissue. the scientists are also testing how to estimate what they can’t count precisely, like animal deaths. one group of evaluators is scattering bird carcasses off- shore and measuring how many sink and how many wash ashore. those numbers will be used to calculate how many birds may have died in addition to the ones that were found and counted.
For all this effort, it will take time for some of the consequences to manifest themselves. It was three years after the Exxon Valdez spill in Prince William Sound in Alaska, for example, that the herring fishery suddenly collapsed.
During the Deepwater Horizon disaster, as the slick was spreading, the federal Fish and Wild- life Service moved about 28,000 eggs from turtles’ nests on at-risk beaches in Alabama to the coast of Florida. While 51 percent of the eggs hatched—roughly consistent with normal survival rates—it will be another two decades or so before the hatchlings that survive come back to Florida as adults to lay eggs. only then will anyone know how successful the rescue effort really was.
Many of the results that have been gained so far, by government or private industry, are not yet public; they are awaiting rigorous review before eventual release. Moreover, in some key cases, scientists must keep their findings confidential because of continuing legal actions.
“We have a real responsibility to make sure that we come out of this process with as much compensation as is appro- priate for the damages,” said Bob Had- dad, chief of the assessment and resto- ration division of the national oceanic and Atmospheric Administration, which is taking the lead in coordinating the damage assessment. “I don’t want to get tripped on issues like inadmissibility of evidence.”
Consider This How might the fact that scientific research findings can be used as evidence in legal cases complicate the work of the scientists involved? What features of the scientific method make it less likely that scientists could, or would, falsify their findings to favor one side or the other in a legal proceeding?
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SECtIon 6.6case history—the GUlF oF Mexico Deep Water horizon oil spill
Oil and Water Do Mix Still, there has been some independent scientific work done in the gulf, and it has produced some good news. Because the spill occurred at very high pressure a mile beneath the ocean’s surface, some of the oil was reduced to tiny droplets that remained suspended thousands of feet deep in a fine mist.
terry C. Hazen, who leads the ecology department at lawrence Berkeley national laboratory, took 170 samples from around the Deepwater Horizon between July 27 and Aug. 26 last year [2010], just weeks after the wellhead was capped.
Dr. Hazen was looking to track the fate of the underwater oil as it spread and instead found it to be entirely gone. “We can detect down to 2 parts per billion,” he said, “but nothing was there.”
His work was financed by a grant his lab won from BP, the owner of the well, long before the spill, and it was not in any way reviewed or influenced by the company, he said.
the results showed that the oil had not just been diluted with water but that it had largely been eaten by naturally occurring bacteria. researchers worried early on that such bacteria might not exist thousands of feet down or that the process of digestion might be particularly slow because of colder temperatures at these depths. But Dr. Hazen’s group found bacteria that specialized in oil eating in frigid temperatures.
Another byproduct of the spill was roughly 200,000 metric tons of methane gas. In June 2010 there was as much as 100,000 times as much methane dissolved gas in the gulf as normal. Sci- entists worried that it could remain dissolved in the water column, depleting oxygen levels, for years.
But by fall, researchers from the university of California, Santa Barbara, and texas A&M took water samples from 207 sites near the spill and found that methane proportions were back to normal.
John Kessler, an oceanographer at texas A&M, said: “It appeared that the methane would be present in the gulf for years to come. Instead, methane respiration rates increased to levels higher than have ever been recorded.”
In other words, bacteria ate it. other scientists, however, are not convinced. Samantha B. Joye, a professor of marine science at the university of Georgia, said her team found elevated meth- ane levels at exactly the time Dr. Kessler’s team did not.
Further, at a recent meeting of the American Association for the Advancement of Science, Dr. Joye said that the digestion of the oil and methane had not been entirely benign. Her team took sediment samples in a roughly 35-square-mile area at several different times, most recently in December, and found the muddy gulf floor covered with a blanket of dead bacte- ria, much of it oily and sticky. At every one of the sites she sampled, she said, bottom-dwelling invertebrates—worms, starfish, even coral—were dead.
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SECtIon 6.6case history—the GUlF oF Mexico Deep Water horizon oil spill
“these are keystone species to the ecosystem,” she said, “and we don’t know what will happen without them.”
Her findings have been substantiated in part by Charles Fisher, a biologist at Pennsylvania State university, who has documented dead fan corals seven miles from the wellhead, prob- ably killed by oil plumes in the deep sea, Dr. Fisher said. “Fan corals live for hundreds, perhaps hundreds of thousands of years,” he said. “the odds that something beside the oil from the spill killed them are vanishingly small.”
Dispersants in Diaspora the fate of some 1.84 million gallons of dispersant poured into the gulf to get the oil to break into smaller pieces and thus degrade more quickly is less definitive than what happened to the oil and methane. Some 770,000 gallons were applied to the wellhead itself.
Dispersants have toxic elements, and at the time critics of the application saw it as a gigantic unregulated experiment.
the Environmental Protection Agency has now done extensive testing on the most commonly used dispersant, Corexit 9500, mixed with louisiana crude and found it to be no more or less toxic to marine life than eight other alternative dispersants or than the oil alone. the E.P.A. administrator, lisa P. Jackson, said that not only was the toxicity of the dispersants evalu- ated, so was their effectiveness. “the chemicals helped break up the oil,” Ms. Jackson said in a recent interview. “It was the right decision to use them.”
that doesn’t mean the dispersants were harmless, however. Elizabeth Kujawinski, an associ- ate scientist in chemistry at Woods Hole, was able to track dispersants using highly sensitive tests. Dr. Kujawinski found that while they have become diluted, they are “not entirely biode- graded or decomposed.”
In other words, she said, they remain in the gulf, but in amounts that the government does not consider dangerous.
“toxicity looks at acute exposure—huge concentration, and then you are done,” she said. “But in case of the Deepwater Horizon it was low concentrations, but over a long period of time. We don’t know about how this affects living creatures in the deep water that can’t move, like corals.”
Sudden Death During the spill, the daily tallies of birds, turtles and sea mammals found dead or alive and covered in oil were heartbreaking. they were also just a beginning.
For every pelican or whale found beached or floating at sea, some much larger number died. After the Exxon Valdez accident, 30,000 birds were found, but 250,000—eight times the num- ber found—were eventually estimated to have been killed by the oil. Each situation is differ- ent, and scientists are trying to pin down the so-called death multipliers for this spill.
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SECtIon 6.6case history—the GUlF oF Mexico Deep Water horizon oil spill
looking at annual carcass recovery rates for 14 groups of cetaceans—the mammal group that includes whales and dolphins—a group of biologists from the university of British Columbia recently said that the multiplier for that group should be around 50. So although 115 ceta- ceans were found dead or stranded during the spill and in the months immediately after, they might represent 5,000 actual deaths.
Melanie Driscoll, director of bird conservation in the gulf for the national Audubon Society, said similar multipliers may need to be applied to 8,000 birds so far discovered by the gov- ernment, especially in a category known as secretive marsh birds. “they already hide in dark grasses naturally, so they were certainly missed,” Ms. Driscoll said.
Some species may, however, have done better than it seemed at first. Jim Franks, a fisheries professor from the university of Southern Mississippi Gulf Coast, has been monitoring larvae of bluefin tuna. While he says oil did affect some of their spawning grounds, it spared some as well. Dr. Franks refuses to say what percentage of larvae might have been killed, but it cer- tainly was not a total wipeout, as had been feared.
Plant life also suffered from the spill. Marshes in Bay Jimmy, south of new orleans, were hit particularly hard and remain coated in heavy oil. unknown amounts of pollution lay buried in the nearby sediments as well. Federal monitors are watching these areas now to see if new grasses come through the oiled ones this spring, or if it may be necessary to burn off some of the old, oiled growth.
And there are the deaths yet to come. In February 59 dolphins were found stranded or dead on northern gulf beaches; 36 were premature or stillborn babies. that was nine times the average number that were found in the years 2002 through 2009. Dolphins began dying before the oil spill; 56 were stranded in March 2010. But the spike in neonatal dolphin deaths is new this year.
“Yes, their mothers were very likely in gestation during the spill,” said Blair Mase, a marine mammal stranding coordinator with the national oceanic and Atmospheric Administration, “and exposure to petroleum in mammals can cause decreased success in keeping young.”
But, Ms. Mase said, there could be other causes. For example, the dolphins may be fighting a virus that appeared before the spill, but is more dangerous because the exposure to oil has weakened the dolphins’ immune systems.
As with so many of the effects of the spill, said Ms. Mase “right now we cannot say for sure.”
Adapted from Kaufman, L. (2011, April 11). Gulf ’s Complexity and Resilience Seen in Studies of Oil Spill. new York times. Retrieved from http://www.nytimes.com/2011/04/12/science/12spill.html. © 2011 The New York Times. All rights reserved. Used by permission and protected by the Copyright Laws of the United States. The printing, copying, redistribution, or retransmission of this Content without express written permission is prohibited.
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SuMMArY & rESourCES
Summary & Resources
Chapter Summary Both minerals and fossil fuels are considered nonrenewable resources. they were formed over hundreds of millions of years, and so our removing them from the Earth means that they are no longer available for exploitation by future generations. this can be contrasted with what are known as renewable resources. If managed properly, water can be withdrawn from a river or groundwater deposit year after year without depleting that resource. Fish can be harvested from a fishery or trees cut from a forest and they will renew or replenish them- selves in a time span meaningful to us. likewise, moving water can generate hydroelectricity, wind can generate wind power, and sunlight can be converted to solar energy, all without depleting the availability of these resources.
In addition to being nonrenewable, minerals and fossil fuels have other things in common. they were both formed and concentrated by geologic processes of pressure, heat, and plate tectonics. Both minerals and fossil fuels are distributed unevenly around the world. And both minerals and fuels are present in varying concentrations, with the most concentrated and easily accessible deposits the first to be exploited by mining and energy companies.
the main environmental impacts of minerals are associated with their extraction and refine- ment. Mining for minerals, especially surface mining, can result in land disturbance, erosion, and water and air pollution. refining minerals, especially metals, can also be a very energy- intensive process. For example, aluminum is produced from bauxite ore. After being dug from the ground, bauxite is refined in a number of steps to remove rocks, dirt, and other material and produce a substance known as alumina. the alumina is then heated to form aluminum alloy, which can then be used to make aluminum sheets for cans, plane fuselages, and other end uses. All of these steps require significant quantities of energy, which is why the main environmental benefit of aluminum recycling is not saving landfill space but saving energy (see section 9.5).
Environmental impacts of fossil fuels are associated both with extraction and use. Drilling for and transporting oil can result in oil spills such as the Gulf oil spill of 2010. Mining for coal can cause large-scale land disturbance such as that seen with so-called mountaintop removal mining (a method of mining where the top of a mountain is removed and dumped into adja- cent valleys in order to expose the coal underneath). Drilling for unconventional natural gas deposits can impact water supplies, such as recent concerns over the use of hydrofracturing in shale formations. Beyond the environmental impacts of extraction there are also serious issues associated with the burning or combustion of fossil fuels. Fossil fuel combustion con- tributes to local and regional air pollution (see section 9.1), as well as to global climate change. In fact, many scientists are now suggesting that long before we worry about “running out” of fossil fuels like oil, coal, and natural gas, we may want to limit their use because of concerns over climate change. the links between fossil fuel use and climate change are explored in more detail in the next chapter. Chapter 8 introduces a number of alternative energy sources that might help us reduce our dependence on fossil fuels.
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SuMMArY & rESourCES
Working Toward Solutions Because minerals and fossil fuels are nonrenewable resources, there are no immediate “solu- tions” to their depletion. Instead, efforts in this area generally focus on better management of these resources, increased efficiency in their use, and minimization of the environmental impacts of their extraction.
In the united States, the u.S. Geological Survey (uSGS; http://www.usgs.gov/) is the main scientific body studying mineral issues. the uSGS is a bureau of the u.S. Department of the Interior and is based in reston, Virginia. the uSGS has compiled a wealth of information on international minerals (http://minerals.usgs.gov/minerals/pubs/country/), mineral resources (http://minerals.usgs.gov/), and other topics (http://www.usgs.gov/science /science.php?term=745). the uSGS also maintains a useful education page (http://education .usgs.gov/) with a lot of information on the science of minerals. In terms of regulation, the environmental impacts of mineral mining are overseen by a number of federal agencies, including the u.S. Environmental Protection Agency (EPA) and offices within the Department of the Interior. the 1977 Surface Mining Control and reclamation Act requires mining com- panies to restore and reclaim mined areas. unfortunately, another federal law, the General Mining Act of 1872, still has a powerful influence over how mineral resources are managed in the united States. the General Mining Act was passed at a time when the nation needed new mineral supplies to support growth and expansion, and so it opened up public lands to mineral exploration and development. In recent decades some mining companies have been able to use the 1872 law to exploit millions of dollars’ worth of minerals from public lands for almost nothing in return. today, a number of campaigns are underway to reform the 1872 Mining Act to bring it into line with today’s realities (http://www.pewenvironment.org/campaigns /pew-campaign-for-responsible-mining/id/328473).
one of the main things we can do as individuals to conserve minerals and reduce the impact of their mining and processing is to recycle metals. take the case of aluminum. It may not seem like much, but your standard aluminum can has a complex, energy-intensive, and pollut- ing life cycle (http://www.personal.psu.edu/lat5088/edsgn100/cans.html). the simple act of recycling that aluminum can brings a number of environmental benefits. First, it reduces the need to mine for and extract new supplies of bauxite ore, the raw material that’s turned into aluminum. Second, it saves an enormous amount of energy that would otherwise be used to convert that bauxite ore into finished aluminum. A basic rule of thumb is that manufacturing a new aluminum can requires 20 times as much energy as recycling an existing one. Another way to conserve important metals is to be sure to recycle so-called e-waste, items such as old cell phones, laptop computers, and portable electronic devices. these electronic gadgets typically contain a mix of valuable metals that can be reused as well as contaminants like lead and cadmium that would otherwise pose a pollution problem if not disposed of properly. the EPA’s eCycling page has information on the e-waste problem and what you can do if you have old electronics to dispose of (http://www.epa.gov/epawaste/conserve/materials/ecycling /index.htm).
At the global level, the International Energy Agency (IEA; http://www.iea.org/) is an inter- governmental organization focused on energy security, economic, and environmental issues.
(continued)
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Working Toward Solutions (continued) Although it has no regulatory authority, the IEA provides policy advice to its member states and conducts research on international energy issues. the IEA’s World Energy outlook (http://www.worldenergyoutlook.org/) is one of the most widely cited reports on global energy trends. However, some critics argue that the IEA overstates the resource potential for fossil fuels and undersells the possibility for renewable alternatives. the u.S. Energy Infor- mation Administration (EIA; http://www.eia.gov/) also compiles a lot of useful information on international and domestic energy supply, demand, and other issues (http://www.eia.gov /cfapps/ipdbproject/IEDIndex3.cfm).
In the united States, the Department of Energy (DoE) is the primary government organization focused on fossil fuels and other energy issues (http://energy.gov/). other government agen- cies, such as the Environmental Protection Agency and the Department of the Interior, are also involved in regulating the environmental impact of energy extraction and use. Much of the oil, gas, and coal produced in the united States comes from resource deposits found on public lands. the Bureau of land Management of the u.S. Department of the Interior is responsible for manag- ing energy exploration and development on these lands (http://www.blm.gov/wo/st/en.html). Energy exploration and development on private lands is regulated by a variety of local, state, and federal rules regarding land disturbance, erosion control, water quality, and air pollution.
Because fossil fuels are a nonrenewable resource, any effort to reduce their use and improve efficiency will extend supplies. In addition, since the extraction and combustion of fossil fuels has a number of environmental impacts—from acid mine drainage to oil spills, local air pol- lution, and global climate change—any improvements in energy use efficiency bring benefits at multiple levels. renewable energy technologies and energy efficiency techniques and pro- grams are described in much more detail in Chapter 8, so just a few will be mentioned here. the u.S. EPA’s Energy Star program helps promote energy efficiency and conservation in build- ing construction, homes, and industrial facilities (http://www.energystar.gov/). the EPA also helps local governments increase their energy efficiency in order to reduce environmental impacts and save taxpayer money (http://www.epa.gov/statelocalclimate/documents/pdf /ee_municipal_operations.pdf). Many state and local governments are also promoting energy efficiency in homes and businesses as a way of improving the local economy. the u.S. Small Business Administration provides a listing of such programs (http://www.sba.gov/content /state-and-local-energy-efficiency-programs).
Besides government agencies, many electric companies and utilities are also promoting energy efficiency and conservation. one particularly interesting approach uses smart meters in homes combined with social media to inform consumers about how they are using energy and suggest ways to save it. A company called opower (http://opower.com/) is one of the pio- neers in this area, and they hope that the combination of data sharing and incentives can help residential customers reduce their energy use by as much as 20 percent (http://e360.yale .edu/feature/how_data_and_social_pressure_can_reduce_home_energy_use/2597/).
In conclusion, there isn’t much any of us can do to change the fact that minerals and fossil fuels are nonrenewable resources. However, there are better and worse ways of extracting, refining, and utilizing these resources. Government policy and programs can have a significant impact on the degree to which mineral and fossil fuel exploration and use impacts the environment. ultimately though, it is individual decisions about how much energy we use and whether to recycle or practice energy efficiency that determine much of what happens in this sector.
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Post-test
1. the Environmental Protection Agency (EPA) reports that adults are at greater risk from exposure to lead than children.
a. true b. False
2. Shale gas is a conventional natural gas deposit. a. true b. False
3. oil companies are showing increasing interest in extracting oil from other hydrocar- bon resources such as tar sands and shale oil.
a. true b. False
4. Geologic carbon sequestration involves separating out carbon dioxide that is created when coal is converted to energy and transporting it to storage sites.
a. true b. False
5. Hydraulic fracturing might pose a threat to the drinking water supply. a. true b. False
6. What does it mean that the death multiplier for cetaceans in the Gulf oil spill is said to be around 50?
a. the number of cetaceans dead from the oil spill is around 50. b. the number of cetaceans found dead multiplied by 50 gives an estimate of the
number of actual deaths. c. the number of cetaceans eventually dying from effects of the oil spill will con-
tinue for around 50 years. d. the recovery rate of cetaceans injured by the oil spill is about 50 animals per
every one found dead.
7. Which of the following is not a phase or stage of the mining life cycle? a. recycling b. Exploration c. Extraction and processing d. Mine closure
8. Which of the following is not found in a conventional oil deposit? a. natural gas b. oil c. Water d. Shale gas
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9. Future oil shortages are not only a concern because of impacts on transportation, but also because oil is an important ingredient in the production of fertilizer and plastics.
a. true b. False
10. Which source of energy produces the MoSt carbon dioxide per unit of electricity generated?
a. oil b. Solar power c. natural gas d. Coal
11. Flowback water from hydraulic fracturing operations in shale deposits is especially worrisome because it might contain
a. nutrients like nitrogen and phosphorous. b. greenhouse gases like carbon dioxide and methane. c. foul-smelling sulfur. d. radioactive elements like strontium.
12. Environmental studies following the 2010 oil spill in the Gulf of Mexico indicate that a. scientists’ predictions were mostly wrong. b. environmental damage results will be conclusive in another three years. c. ocean bacteria destroyed the oil droplets and the dispersants equally. d. conclusions about oil spill damage can be surprising and complex.
Answers 1. b. False. the answer can be found in section 6.1. 2. b. False. the answer can be found in section 6.2. 3. a. true. the answer can be found in section 6.3. 4. a. true. the answer can be found in section 6.4. 5. a. true. the answer can be found in section 6.5. 6. b. the number of cetaceans found dead multiplied by 50 gives an estimate of the number of actual deaths.
the answer can be found in section 6.6. 7. a. recycling. the answer can be found in section 6.1. 8. d. Shale gas. the answer can be found in section 6.2. 9. a. true. the answer can be found in section 6.3. 10. d. Coal. the answer can be found in section 6.4. 11. d. radioactive elements like strontium. the answer can be found in section 6.5. 12. d. conclusions about oil spill damage can be surprising and complex. the answer can be found in section 6.6.
Key Ideas • A mineral deposit is a concentration of a naturally occurring, inorganic solid. the
process of finding, extracting, mining, and processing a mineral, followed by the reclamation of the mining site, is known as the mining life cycle.
• Mining companies utilize three main methods to recover minerals: underground min- ing, surface or open pit mining, and in situ mining.
• Mining for minerals can cause serious, negative environmental impacts to air quality, land, and water quality.
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• Fossil fuels such as oil, coal, or natural gas can be classified using the idea of a pyramid. At the top of the pyramid are fossil fuel deposits that are high quality and easy to access and exploit. Further down the pyramid are fossil fuel deposits that are lower quality and are more difficult to access and exploit.
• Proved reserves of fossil fuels are deposits that have been discovered and deter- mined to be recoverable but are still in the ground. undiscovered resources of fossil fuels have not yet been discovered but are believed to exist in an area based on its geological characteristics.
• Conventional fossil fuel deposits consist of a layered arrangement of natural gas, oil, and water and have provided most of the oil and gas produced in the past. oil and gas that’s distributed over a wide area of a geologic formation is called an unconven- tional deposit. unconventional deposits may contain large amounts of oil and gas, but because the resource is dispersed over such a large area it may not be economi- cally recoverable.
• three important forms of unconventional fossil fuel deposits are oil shale, shale gas, and methane hydrates. though potentially available in vast quantities, each of these energy forms is characterized by significant technical or environmental challenges in production.
• Petroleum geologists, energy economists, and others are currently engaged in a fierce debate over the future of world oil supplies. Some experts believe that we have already reached a point of “peak oil” and that world oil production is on an inevitable downward trend. they argue that we need to start moving aggressively to get off of oil as our primary energy source if we are to avoid economic collapse. oth- ers argue that advances in oil discovery and extraction techniques will continuously increase known oil reserves far into the future.
• Carbon capture and storage (CCS) is a technique that separates out carbon dioxide (Co2) created by coal-fired power plants and pumps it deep underground for long- term storage. CCS is intended to keep as much Co2 as possible out of the atmosphere since it contributes to global climate change. While CCS is currently technically fea- sible, it leads to higher electricity prices and there are questions about its safety. the debate now is whether to immediately start building coal-fired power plants that use CCS, or simply build plants that can be converted to CCS in the future.
• Growing demand for natural gas and declining supplies of conventional gas deposits have spurred increased interest in the development and exploitation of unconven- tional shale gas deposits. Shale gas is found in shale rocks that have low permeabil- ity, trapping the gas in place. the use of a technique known as hydraulic fracturing allows energy companies to increase permeability and the flow of gas from shale deposits. Because hydraulic fracturing requires thousands to millions of gallons of water and generates dangerous water pollutants in the process, this technique is subject to increasing regulatory scrutiny.
• the 2010 Deepwater Horizon oil spill in the Gulf of Mexico was the worst accidental spill in American history. In the years following this disaster scientists were busy assessing the full ecological impacts of the disaster. While this research has con- firmed serious impacts on birds, marine mammals, deep-sea life forms, and coastal wetlands, it has also resulted in some surprises. For example, much of the oil that was released during the spill has already been consumed by naturally occurring bacteria.
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Critical thinking and Discussion Questions
1. Geologists and mining companies often locate mineral deposits that they decide not to mine or exploit because the process of extracting and refining the mineral would cost more than what it’s worth. later, however, mining companies may return to the same deposits and exploit them because they can now do so in a way that’s profit- able. What might be some of the main reasons for a change like this? What factors might explain a shift in the profitability of a given mineral deposit?
2. Geologists, government agencies, and energy and mining companies make use of dif- ferent terms to describe estimated quantities of fossil fuels still in the ground. these depend on how certain they are about the size of a deposit, the quality of the fossil fuel in that deposit, and whether it represents a conventional or unconventional resource. In what ways do you think the scientific method—making observations, asking questions, forming hypotheses, testing hypotheses, and forming conclu- sions—has helped scientists develop estimates of fossil fuel deposits? How might the scientific method be used to help scientists determine how a specific fossil fuel deposit should be categorized?
3. Imagining life without relatively cheap and abundant supplies of oil is difficult for those of us who have grown up in an age of oil. However, the peak oil concept suggests that we may have to do just that, and perhaps sooner than many realize. Consider your own life and daily routines and all of the ways that you make use of oil directly or indirectly. How difficult or inconvenient would it be for you to adapt to a world with far more limited oil supplies? What aspects of your life would be impacted the most? Can you think of any unintended but positive outcomes of such a change?
4. While carbon capture and storage (CCS) techniques have the potential to reduce emissions of carbon dioxide (Co2) from coal plants to the atmosphere, there are many other social and environmental problems associated with the extraction and use of coal as an energy source. What are some of these problems? Even if CCS is widely implemented, should we still be making so much use of coal? the authors of the article on the future of coal state that “[c]oal’s market price may be low, but the true costs of its extraction, processing, and consumption are high.” How can there be a difference between a commodity’s market price and true costs?
5. the development of all fossil fuel energy sources causes some sort of environmental impact. offshore oil drilling can lead to catastrophic oil spills. Mountaintop removal coal mining can scar landscapes and destroy streams and waterways. And hydraulic fracturing of unconventional shale gas deposits can deplete local water supplies and contaminate drinking water wells and surface water bodies. How should society pro- ceed with the regulation and management of these environmental impacts of energy development? We all use this energy in our everyday lives, and its availability helps keep our economy running. Yet, the environmental impacts of energy development can also impose significant health costs on society and ruin the livelihoods of those dependent on a clean environment, such as fishermen in the Gulf of Mexico. How do we weigh these tradeoffs? What steps should be taken to ensure the minimum envi- ronmental impacts possible? How might these steps increase the cost of energy, and are the benefits worth the extra cost?
6. In the chapter case study, notice the give-and-take between scientists who reach somewhat different conclusions about the same issue. For example, terry Hazen of the lawrence Berkeley national laboratory was pleasantly surprised to find
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carbon capture and storage the process of capturing carbon dioxide from large sources such as fossil fuel power plants and storing it in such a way that it does not enter the atmosphere.
conventional deposit layered arrange- ment within a reservoir where natural gas is found at the top, oil is pooled below the gas, and water fills the reservoir below the gas; historically has provided most of the oil and gas produced.
demonstrated reserve base the primary statistic reported by the EIA showing coal resources that have been identified and may be economically recoverable.
Energy Information Administration Agency within the u.S. Department of Energy that collects, analyzes, and disperses independent and impartial energy infor- mation in order to promote sound policy making, efficient markets, and public under- standing of energy and its interaction with the economy and the environment.
hydraulic fracturing Process involving the use of a high-pressure fluid to fracture rock formations so that natural gas is released and can be collected; also known as hydro- fracturing or fracking.
inorganic Composed of non-living matter, that is, matter that is neither animal nor plant.
“in-place” resources term describing all the oil, natural gas, or coal contained in a formation or basin without regard to techni- cal or economic recoverability.
methane hydrate reserves of ice- encrusted natural gas found in porous rock.
Natural Resource Damage Assessment the process of collecting and analyzing information to evaluate the nature and extent of damages resulting from an ecologi- cal incident, and determine the restoration actions needed to repair the affected natural resources and services and make the envi- ronment and public whole for interim losses.
nonrenewable unable to be replaced, or replaced very slowly by natural processes.
oil shale Fine-grained sedimentary rock from which oil can be extracted.
ore Solid material found naturally in the Earth that contains economically extractable metals.
organic of, related to, or made from living matter.
proved reserves Sources of oil, natural gas, or coal that have been discovered and determined to be recoverable but have not yet produced.
virtually no trace of oil remaining near the site of the disaster just weeks after the spill was capped. However, Samantha Joye of the university of Georgia found evi- dence that much of the oil was consumed by bacteria that then sank to the bottom and smothered marine life there. Is it natural for scientists to reach different conclu- sions in the course of their research? What is it about a large-scale environmental disaster like the Deepwater Horizon spill that might increase the chances of scien- tific disagreement? Does this represent a strength or a weakness of the scientific method?
Key terms
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Additional resources A number of excellent sources that review the mining cycle and the environmental impacts of mineral mining and use can be found here:
• https://www.elaw.org/files/mining-eia-guidebook/Chapter1.pdf • http://cnx.org/content/m41470/latest/?collection=col11325/latest • http://pubs.iied.org/pdfs/G00902.pdf • http://web.mit.edu/12.000/www/m2016/finalwebsite/problems/mining.html,
http://web.mit.edu/12.000/www/m2016/finalwebsite/problems/refining.html, and http://web.mit.edu/12.000/www/m2016/finalwebsite/problems/disposal.html
• http://www.agiweb.org/environment/publications/metalsfull.pdf • http://www.learner.org/courses/envsci/unit/text.php?unit=10&secnum=13
the u.S. Geological Survey (uSGS) has a variety of domestic and international maps showing the distribution of mineral resources:
• http://mrdata.usgs.gov/
the Department of Energy has a site that provides a basic explanation of how fossil fuels were formed:
• http://www.fossil.energy.gov/education/energylessons/coal/gen_howformed.html
this chapter from the Habitable Planet text provides a lot of information on energy issues in general. Sections 1–5 are focused on fossil fuels. this section also includes a video explaining some of these issues:
• http://www.learner.org/courses/envsci/unit/text.php?unit=10 • http://www.learner.org/courses/envsci/unit/text.php?unit=10&secnum=1
this Discovery news article reviews debates over how much fossil fuel remains in the Earth:
• http://news.discovery.com/earth/global-warming/how-much-fossil-fuel-is-in-the -earth.htm
reclamation the process of reshaping land disturbed by mining so that it is in better condition than before mining began, often creating such post-mining uses as farmland, pastureland, and wildlife habitat.
shale gas A natural gas produced from a sedimentary rock called shale.
tailings Materials left over after extracting a resource of value from earth or rock.
unconventional deposit the distribution of oil or natural gas spread throughout a wide area of a geological formation.
undiscovered resources Sources of oil, natural gas, or coal that have not been discovered but are estimated to exist based on examination of an area’s geological characteristics.
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this article examines some of the problems associated with the development of oil from tar sands:
• http://e360.yale.edu/feature/with_tar_sands_development_growing_concern_on _water_use/2672/
these two articles from National Geographic Magazine and The Economist discuss the end of cheap oil and the future of the peak oil debate:
• http://ngm.nationalgeographic.com/ngm/0406/feature5/fulltext.html • http://www.economist.com/node/15065719
one of the most widely cited international energy reports is published by BP. the BP Statisti- cal review of World Energy has some very interesting charts and maps that show the global distribution of oil and other fossil fuel resources:
• http://www.bp.com/content/dam/bp/pdf/statistical-review/statistical_review_of _world_energy_2013.pdf
this video and article from The Atlantic Guide to Energy Series examines what’s in crude oil and how we make use of this product:
• http://www.theatlantic.com/video/archive/2013/08/whats-in-crude-oil-and-how -do-we-use-it/278645/
• http://www.theatlantic.com/technology/archive/2013/08/turning-crude-oil-into -the-stuff-we-use/278680/
three different but very detailed and comprehensive resources on the basics of carbon cap- ture and storage can be found at these sites:
• http://www.fossil.energy.gov/programs/sequestration/capture/ • http://sequestration.mit.edu/ • http://www.wri.org/our-work/project/carbon-dioxide-capture-and-storage-ccs
The Guardian newspaper has a very nice interactive guide to carbon capture and storage:
• http://www.guardian.co.uk/environment/interactive/2008/jun/12/carbon.capture
Even with carbon capture and storage coal will remain the dirtiest and most environmentally destructive of all fossil fuels. these sources help to explain why:
• http://energy-reality.org/wp-content/uploads/2013/06/07_Coal-the-Greatest -threat_r1_032613.pdf
• http://energy-reality.org/wp-content/uploads/2013/06/17_False-Promise _r1_042413.pdf
• http://www.nrdc.org/globalwarming/files/coalmining.pdf • http://www.ucsusa.org/clean_energy/coalvswind/c02c.html • http://www.catf.us/resources/publications/files/Cradle_to_Grave.pdf
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Perhaps the best place to start looking for information on hydraulic fracturing and shale gas resources is the special series in the New York Times titled “Drilling Down”:
• http://www.nytimes.com/interactive/us/DrIllInG_DoWn_SErIES.html
other good sources on shale gas include resources for the Future and Penn State university’s Marcellus Center:
• http://www.rff.org/research_topics/Pages/Subtopics.aspx?Subtopic=Shale%20 Gas
• http://www.marcellus.psu.edu/
Popular Mechanics magazine has a nice slide show feature on the top 10 controversial claims about natural gas drilling:
• http://www.popularmechanics.com/science/energy/coal-oil-gas/top-10-myths -about-natural-gas-drilling-6386593#slide-1
The Atlantic has a short animated video that explains what’s behind the shale gas boom and an article that explores the processes and problems associated with the development of this resource:
• http://www.theatlantic.com/video/archive/2013/08/whats-behind-the-natural -gas-boom/278897/
• http://www.theatlantic.com/technology/archive/2013/08/the-natural-gas -boom-processes-production-and-problems/278913/
Finally, the investigative journalism group Pro Publica has compiled a lot of useful resources on shale gas exploration and development:
• http://www.propublica.org/series/fracking • http://www.propublica.org/special/hydraulic-fracturing-national
two comprehensive sources of information on the Gulf of Mexico oil spill are available from Nature magazine and the national oceanic and Atmospheric Administration:
• http://www.nature.com/news/specials/deepwater/index.html • http://response.restoration.noaa.gov/deepwaterhorizon
the u.S. government has put together a site describing efforts to restore the health of the Gulf of Mexico:
• http://www.restorethegulf.gov/
lastly, The Guardian has a detailed timeline of the Gulf of Mexico disaster:
• http://www.guardian.co.uk/environment/interactive/2010/jul/08/bp-oil-spill -timeline-interactive
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