We are entering an age of energy abundance. Or not. In keeping with the great tradition of economics, dubbed by Thomas Carlyle the dismal science, let me raise a cautionary note. What God has showered upon us, politicians can make unavailable. Not only because they have to balance our need for energy supplies adequate to support economic growth against the need to prevent unnecessary damage to the environment. More important from their point of view, they have to try to appease voters who want both cheap energy, which means coal, and greener sources that are more costly.

Start with coal, a fuel that damages the earth surface when removed by strip-mining, causes deaths when removed from underground mines, and pollutes the air. Coal now fuels about 40 percent of the world’s energy production, which is rising rapidly—at the rate of one Brazil per year according to Robert Bryce, a senior fellow at the Manhattan Institute, a think tank. America styles itself “the Saudi Arabia of coal,” and with reason. A single mine in Wyoming produces three tons of coal per second, and we sit on enough coal to last us for 250 years.