This article is a response to an article by David Victor and Richard Morse in our September / October 2009 issue

In “Living with Coal,” David Victor and Richard Morse proceed from the sensible premise that our nation needs to reduce carbon dioxide emissions from coal. But their other premise—that coal in some form or other will inevitably remain the mainstay of U.S. electricity generation because it is so cheap and abundant that other energy sources will not be able to displace it anytime soon—is arguable.

The authors do not mention a growing body of reports suggesting that future coal supplies are in fact substantially overestimated and that, therefore, coal may not remain the cheapest source of electric power for much longer. The reports, including ones from the National Academy of Sciences (NAS), Germany’s Energy Watch Group, and Dr. David Rutlege of Caltech, do not deny that the total coal resource base in the United States and worldwide is enormous. At question is the amount of coal that can practically be mined.

The first scientific survey of U.S. coal reserves (in 1905) suggested that the nation had a 5,000-year supply. We are now told, on the basis of surveys undertaken in the 1970s, that the United States has enough coal for 250 years—a “loss” of 4,750 years’ worth of the nation’s coal in just six decades. It is tempting to assume that the early survey was simply wrong and that improved methods and technologies have since revealed this. In fact, most of the coal surveyed in 1905 was not only real, but still exists. Today, however, energy agencies recognize that, after accounting for various “restrictions” (location, depth, seam thickness, chemical impurities), only a small portion of the total coal resource is ever likely to be mined. Other nations have likewise seen dramatic shrinkage in estimates of economically recoverable coal reserves, and that process of downgrading reserves is ongoing. In recent years, Germany’s coal reserves were reduced by about 99 percent due to new surveys and better accounting practices. According to the NAS, if a comprehensive and systematic survey of U.S. coal reserves were performed today, it would probably arrive at supply estimates significantly smaller than those still used by most planning agencies.

Energy Watch Group has estimated that “peak coal” will arrive in the United States by 2020 or 2030—well within the operational lifetime of coal-fired power plants on the drawing boards today.

Moreover, future coal supplies are almost always framed in terms of a reserves-to-production ratio: if current reserves are consumed at current rates, they will last so many years. But natural-resource extraction never proceeds at static rates until exhaustion occurs. Instead, extraction follows a curve that begins at zero, reaches a maximum, and then trails off. This is not a matter of theory but of observation: we can see an almost complete bell-curve extraction history with, for example, British coal and the anthracite mined from Pennsylvania. The question that concerns policymakers and economic forecasters should not be , but Energy Watch Group has estimated that “peak coal” will arrive in the United States by 2020 or 2030—well within the operational lifetime of coal-fired power plants on the drawing boards today.

The problem for China is far worse. That country uses twice as much coal as the United States does, but has only half the reserves. China’s economic powerhouse runs overwhelmingly on coal, and when supplies dwindle, its legendary growth engine may sputter and stall. China recently bought an Australian coal company, evidently as a way of securing additional supplies to supplement domestic production.

As Victor and Morse point out, technology to capture and store carbon dioxide from coal-fired power plants will be expensive both to develop and to operate. A national system of pipelines, compressors, and pumps will be required; the volume of carbon dioxide that would have to be moved and stored exceeds total U.S. oil production, so existing infrastructure will take us only so far. And the system will require decades to build. Such a gargantuan infrastructure investment barely makes economic sense if coal can be guaranteed to remain cheap for many decades to come. If it cannot, the case for “clean coal” simply falls apart as other energy options become cheaper by comparison.

How credible are concerns about peak coal? Planners might feel justified in ignoring warnings not yet reflected in official projections of the U.S. Department of Energy. However, as noted above, these official projections rely on decades-old surveys. The U.S. Geological Survey has recently conducted a series of limited field studies in selected coal regions, and the results have tended to underscore doubts about future coal supplies. For example, in its 2008 report on the Gillette coalfield of the Powder River Basin in Wyoming (the most productive area in the United States), the agency’s geologists found that only 6 percent of the coal in place should be considered economically accessible. The 10.1 billion tons of economically accessible coal at Powder River Basin identified in the report would last only about 22 years at present rates of production.

Of course, coal will not go away overnight. Resource depletion is gradual, and so is the process of exchanging one national energy infrastructure for another. Nor is anyone suggesting that coal prices will skyrocket in the immediate future (though prices are already becoming increasingly volatile: witness the doubling of coal prices in 2007—2008). But it would be hazardous to overlook accumulating information about coal-supply limits when discussing the future of this important fuel and its dominant role in the generation of electricity in the United States.

If, in light of practical supply limits, carbon capture and sequestration are likely to be economically unfeasible, shouldn’t national energy policy bypass that temporary and expensive technological stopgap and go straight for the long-term solutions to our national energy problem—conservation and renewables? It is a pressing question with enormous implications, but we will only be able to address it knowledgably when we have a better idea of how much coal can be mined, and at what price. A new, realistic national coal survey is badly needed.