Between 2006 and 2011 the US cut its CO2 emissions by nearly half a billion metric tons—more than any other country in the world. This remarkable decline overlaps with the boom in shale gas production, triggered by the large-scale commercialization of fracking technology. The production of natural gas has since soared, and the price has tumbled. Suddenly natural gas has emerged as a more attractive fuel for electricity generation than coal.
This is a new trend. For decades coal was the favored fuel for electricity generation. Particularly after the 1973 Arab oil embargo, the US government limited natural gas use in industries and power plants out of fear that we would exhaust our domestic reserves and be unprepared for the next crisis. This restriction on natural gas led to a steep rise in electricity generation from coal.