Coal is essentially a kind of “compacted sunlight.” It is a combustible material derived from leafy biomass that has absorbed energy from the sun and has been compressed in the earth over geologic time. It is usually found in seams associated with other sedimentary rock. Historically, Earth went through the Carboniferous age about 350 to 290 million years ago. During this period, Earth was like a hothouse, with a higher average temperature than today and a steamy atmosphere that caused plants to grow rapidly. Using sunlight and moving through their life cycles, layer upon layer of plants accumulated on the surface of the earth. These plant materials gradually developed into peat bogs, and many of the bogs became covered with other material and were subjected to pressure over geologic time, eventually turning into coal. The result today is that we find an abundance of coal, often associated with sedimentary rock such as limestone, sandstone, and shale.
I. What Is Coal?
II. Effects of Mining and Storage
III. Coal Quality
IV. Two Levels of Paradox
V. Population Needs
What Is Coal?
From a human perspective, coal is a nonrenewable resource. From a geological perspective, coal could be renewed from sunlight and plants over eons, but this would require another carboniferous (hothouse) era, which would not be very congenial to humans.
Peat is the first stage in the development of coal. It has very high water content and is not a good fuel if actual coal is available. When peat is compressed, it first becomes lignite or “brown coal.” With further compression, brown coal becomes bituminous coal (soft coal). Finally, with both heat and high compression, we get anthracite or “hard coal,” which has the least moisture content and the highest heat value.
Effects of Mining and Storage
Coal mining directly affects the environment. Surface mining produces waste materials, including destroyed trees and plants, but also substantial amounts of waste rock. When a small mountain is stripped for coal, waste rock is often dumped in valleys, and this can generate acid contamination of water. Surface mining also generates considerable dust (the technical name for this is “fugitive dust emissions”). Underground mining occurs largely out of sight but can result in large areas of subsidence. The generation of methane (and other gases) and acid mine drainage into local aquifers can also occur. After coal is mined, the next step is called coal beneficiation. In this step, coal is cleaned of some of the impurities that have interpenetrated it because of surrounding rock formations and geologic activity over several million years. This generates waste streams, including coal slurry and solid wastes that must go somewhere. Then, the cleaned coal has to be stored, handled, and transported. Handling and transportation produce more fugitive dust emissions.
There are examples of both surface and underground mining in which great care has been taken to mitigate these and other environmental effects. However, the effects on local environment can be severe, as shown in many other cases. Coal combustion byproducts (CCBs) are the waste material left over from burning coal. CCBs include fl y ash, bottom ash, boiler slag, and flue gas desulfurization (FGD) material. Between 30 and 84 percent of this material can be recycled into other products such as concrete, road construction material, wallboard, fillers, and extenders. The rest is waste, which may include toxic elements that can cause human health problems if they are inhaled (as dust in the wind) or if they get into groundwater.
Emissions from coal combustion include water vapor (steam), carbon dioxide, nitrogen, sulfur, nitrogen oxides, particulate matter, trace elements, and organic compounds. The sulfur dioxide released may transform into sulfur trioxide (sulfuric acid). Nitrogen oxides contribute to the formation of acid rain. Particulate matter causes lessened visibility and, if the particles are breathed, can have serious health consequences, including asthma, decreased lung function, and death. Carbon dioxide is a major component of greenhouse gases. A certain balance of greenhouse gases is necessary to keep the planet habitable, but too much greenhouse gas contributes strongly to global warming. Carbon sequestration is the term for capturing carbon dioxide and storing it somewhere.
Carbon sequestration is the attempt to mitigate the buildup of carbon dioxide in the atmosphere by providing means of long-term storage—for example, by capturing carbon dioxide where coal is burned and attempting to inject it into the earth, the oceans, or growing biomass. The questions to ask about proposed methods of carbon sequestration are the following: How long will it stay sequestered before it is released back to the atmosphere? And will there be any unintended side effects of the carbon dioxide in the place in which it is to be put? We also need to be aware of what is sometimes called “silo thinking”—that is, trying to solve an important problem without being aware of interactions and linkages. Right now, fish stocks are declining and ocean coral is dissolving because the oceans are becoming more acidic. Putting huge additional amounts of carbon dioxide in the oceans might help to make power plants “cleaner,” but it would more quickly kill off many forms of aquatic life.
Despite some of these effects, however, coal will continue to be the dominant fuel used to produce electricity because of its availability and lower price compared with other forms of electricity generation. At the same time, carbon dioxide released in the burning of coal is a large contributor to rapid global warming. This is a contradiction without an easy solution. If efficiency, widespread availability, and lowest cost are the relevant criteria, then coal is the best fuel. If we choose in terms of these standard market criteria, we will also move quickly into global warming and climate change. The physical root of the problem is primarily one of scale: a small planet with a small atmosphere relative to the size of the human population and its demand for the use of coal.
It is a simple fact that the use of electricity is increasing all over the planet. The intensity of electricity use is growing gradually, year by year, throughout the economically developed portions of the planet, particularly because of the ubiquitous use of computers and the placing of increasing machine intelligence into other business and consumer devices. The poor and so-called backward regions of the planet continue to electrify largely in response to their penetration by multinational corporations as an aspect of globalization. At the same time, intermediately developed countries with rapidly growing economies, such as India and China, are experiencing the emergence of strong consumer economies and rapid industrial development. For the near and intermediate future, these (and other) major countries will require substantial numbers of new central generating stations. Meaningfully lowering the demand for electricity would require major changes in our patterns of life, such as moving away from a consumer society and business system and a reorientation of housing and cities to maximize the use of passive solar energy, as well as a transition to local DC power systems in homes.
Historically, the high-quality heat developed from good-quality coal is responsible for much of the success of the industrial revolution in the Western economies. The transition from the stink of agricultural life and the stench and illnesses of early industrial cities to clean, modern living—characterized by the mass production of consumer goods—is highly dependent on clean electricity. Coal kept us warm, permitted the manufacture of steel products, and gave us much of our electricity over the last century. With only a little coal, natural gas, and oil, the human population of the planet would have been limited largely to the possibilities of wind and sun power; history would have developed very differently, and the human population of the planet would be only a small percentage of its size today. It is important to know that doing without coal, gas, and oil would have the reverse implication for the carrying capacity of the planet. At root, the issue is not only the historic and continuing advancement of civilization but also the size and quality of life of populations that are dependent on coal, natural gas, and oil. That is why securing these resources is so integral to the trade and military policies of nations.
Two Levels of Paradox
Whereas coal has been a wonderful resource for human development and the multiplication of the human population, there is a paradox: electricity, which is so clean at the point of use, is associated with extreme carbon loading of the atmosphere if it is generated from coal. This contradiction originally existed only at a local level. As an illustration, Pittsburgh, a major industrial center in America, was long known as a dirty coal and steel town, with unhealthy air caused by the huge steel plants, the use of coal for electricity generation, and the general use of coal for home and business heating in a climate with long cold winters. The air was often dirty and the sky burdened with smoke and dust.
This was initially taken as a sign of economic vigor and prosperity. Pittsburgh’s air was cleaned up in the early 1950s by the requirement of very high smokestacks and a shifting away from nonindustrial uses of coal for public health and civic betterment reasons. The tall smokestacks, however, while providing a local solution, simply transferred the problem to places downwind. This is a reality of pollutants: they do not go away; they go somewhere else. Places downwind of the Midwestern power plants (such as New York City) experienced more unhealthy air days, and lakes in the mountains downwind began to die because of acid rain. This is the local level of the paradox—clean electricity and efficient large-scale industry produce local or regional pollution problems because of the use of coal.
Similarly, the global level of the paradox is that the use of coal is responsible for significantly fouling the planet, leading to a common future filled with the multiple disasters associated with global warming. Just a few of these experiences we have to look forward to include the submergence of coastal areas, loss of ice at the poles, loss of snowpack on mountains, invasions of species from other areas against weakened natural species, dramatic food shortages, and an increasing number of riots in poor areas where the rising cost of food cannot be met within the local structure of wages— not a war of “all against all” but one of increasing numbers of persons increasingly shut out of the economic system against those still protected by remaining institutional arrangements or by wealth. As resources contract, in addition to the problems of food shortages and new outbreaks of disease, the resulting income gap will likely signal a return to the social inequalities of the Victorian era.
An underlying variable, of course, is the size of the human population. If we were facing a few new power plants and limited industrial production, the myth of unlimited resources that underlies conventional economics would be approximately true. It would not matter much if we fouled a few localities if the human population were one-hundredth or one-thousandth of its current size and the planet were covered with vibrant meadows and ancient forests.
With a much smaller human population, the fouling of the planet would be less of an immediate problem. But given the size of the human population, the need is for several hundred new power plants. The demand through market forces for consumer goods, industrial goods, and electricity, particularly from the portion of the human population engaged in unsustainable modern market economies, drives the need for hundreds of new central power plants in the immediate to intermediate future.
Industry in India and China, in particular, is taking off along a huge growth curve, different from but in many ways similar to that of the industrial revolution in the West. In our current situation, coal is, on the one hand, the preferred market solution because it is relatively inexpensive, is a widespread and still abundant resource (in contrast to gas and oil), and can provide power through electricity generation that is clean at the point of use. The problem at the global level is the size of the planet and the limited atmosphere in relation to the size of human population. The scale of what is required will generate far too much pollution for the planet to handle in ways that keep the planetary environment congenial to humankind.
It is possible, however, to talk about “clean coal.” This term has two meanings. First, some types of coal emit less carbon into the atmosphere when burned, and some deposits of coal contain much less foreign material than others. Cleaner coal is more expensive than dirty coal. Second, the phrase is a slogan of the coal industry pointing toward the concept of capturing gas emissions from coal burning. As a slogan, it serves the purpose of conveying the image of a future in which commercial-scale coal-burning power plants would emit no carbon dioxide. Research on this problem is ongoing, but there are no such plants at the present time.
The U.S. FutureGen project is on hold after federal funding from the Department of Energy was pulled. The questions to ask about the promised “clean coal” future are these: What is the scale of transfer of carbon dioxide that would be required (if it could be captured)? What would be done with the massive quantities that would have to be sequestered, and would this have any unintended consequences?
Coal is less expensive than other fuels, but this is due in part to the free market system in which the social and environmental costs of coal are treated as what economists like to call “externalities.” That is, these costs are left for other people—for regional victims of pollution—and for global society to bear. Several systems have been proposed to transfer all or part of these costs to companies that burn massive amounts of coal, such as electric utilities. In fact, a sector of the electric utility industry is currently campaigning to have some form of carbon trading or carbon tax imposed. It is generally expected that this will occur in the not-too-distant future, given that many industry leaders would like to resolve the ambiguity and uncertainty of what form these costs will take and to speed the new system into place. This may substantially increase the cost of coal as an energy resource.
Coal has had and continues to have a major role in the advancement of civilization. It is currently more abundant and more easily available than other major fuels. Its concentrated energy (high heat content) permits us to create steel products. Without coal, natural gas, and oil, the human carrying capacity of the planet would be a small percentage of the current human population. Yet there is a contradiction inherent in the massive use of coal and in the building of hundreds of new generating stations that depend on coal because carbon release will hasten global warming and also produce other environment effects that are not helpful to human life. This is a contradiction without an easy solution.
- Brune, Michael, Coming Clean: America’s Addiction to Oil and Coal. San Francisco: Sierra Club Books, 2008.
- Freese, Barbara, Coal: A Human History. Cambridge, MA: Perseus, 2003.
- Heinberg, Richard, Blackout: Coal, Climate, and the Last Energy Crisis. Gabriola Island, BC: New Society Publishers, 2009.
- Kilroy, Johnny, “EPA Proposes New Rule to Regulate Coal Ash.” Tenthmil. May 5, 2010. http://tenthmil.com/campaigns/policy/epa_proposes_new_rule_to_regulate_coal_ash
- McKeown, Alice, “The Dirty Truth about Coal.” Sierra Club monograph. http://www.sierraclub.org/coal/downloads/coalreport.pdf
- Miller, Bruce G., Coal Energy Systems. San Diego, CA: Elsevier, 2005.
- Shogren, Elizabeth, “Tennessee Spill: The Exxon Valdez of Coal Ash?” National Public Radio. December 31, 2008. http://www.npr.org/templates/story/story.php?storyId=98857483
- “Toxic Tsunami,” Newsweek ( July 18, 2009). http://www.thedailybeast.com/newsweek/2009/07/17/toxic-tsunami.html
- Ward, Kenneth, Jr., “Mining the Mountains: Tennessee Coal Ash Spill Highlights Broad Gaps in Government Oversight.” Charleston Gazette (December 30, 2008). http://www.wvgazette.com/News/MiningtheMountains/200812290514
- Ward, Kenneth, Jr., “EPA Backed Off Tougher Coal-Ash Proposal Amid Industry Complaints, White House Review.” Charleston Gazette (May 7, 2010). http://blogs.wvgazette.com/coaltattoo/2010/05/07/epa-backed-off-tougher-coal-ash-proposal-amid-industry-complaints-white-house-review/