The new watchword in the coal mining industry is carbon sequestration. Those who mine coal and those who burn it (primarily electric utilities) are less likely than their counterparts in the oil and gas business to discount the dangers of oil and gas depletion. And, they have an entirely predictable solution: Mine more coal. The natural followup question is: What about global warming? From coal advocates we get another entirely predicable answer: carbon sequestration (i.e., storing the carbon dioxide created by the combustion of coal someplace other than the atmosphere).
These advocates are eager to turn coal into liquid fuel, into slurries for pipeline transport, and into cleaner burning synthetic gas for fuel and chemical feedstocks. In fact, they envision a return to a coal economy as the oil and gas economy declines. They do have one very important fact in their favor: The world still has gigantic reserves of coal, one quadrillion short tons according to the U. S. Energy Information Administration.
Of course, there are questions about the energy content of that remaining coal. Will we reach a point (sooner than we expect) at which the net energy from coal begins to decline precipitously and even turns negative making it an energy sink instead of an energy source? Will we find that as we increase our use of coal, a worldwide peak in production will come much earlier than we thought? And, wouldn't we then face the same challenge all over again of having to move quickly to renewable sources of energy?
But, let us set all these concerns aside for the moment and focus on the question of carbon sequestration. Not too long ago I spoke about oil depletion before a Chamber of Commerce-sponsored gathering. I suggested that we as a world society might decide to return to a coal economy. While that might prove practical in the short run, I explained, it would probably be disastrous in the long run because of the damage it would do to the climate.
Afterwards an engineer who works for a large utility approached me. He explained that his company was already successfully sequestering carbon dioxide underground in a pilot program at a generating plant in Virginia. I asked him how long the company was planning to test its program before expanding it. Would it be five years? 10 years? How long will the company wait to be sure that the carbon dioxide doesn't leak out at a later date, possibly by some process as yet unknown? What if any failure of the company's sequestration method doesn't show up until the 11th year?
He responded, "Well, maybe any leakage will be slow."
Are we really willing to bet the future of human civilization on coal based on that response?