Bloomberg is anti-coal for a long time. He is an ignorant soul. People at very high position can be totally ignorant and science illiterate. Former Vice-President Al Gore said the center of the earth is at a few million degrees of temperature. He was ignorant.
The fact of the matter is US has dwindling oil supply. US conventional oil production peaked in 1970 and has been in decline since. US conventional natural gas supply also peaked and is in steep decline.
The un-conventional energy source, shale oil and shale gas, was boasted by some as worth 100 years worth of supply. That's pure fiction. The 100 years of supply constitute mostly of not-yet-discovered and non-exist supply. Counting discovered and proven natural gas supply, the US shale gas reserve is enough to last maybe 7 years, not 100 years.
Coal remains the corner stone of US energy supply. Coal is the most reliable and long lasting energy source that America has. Coal is dirty. No one denies that. We hope technology progress can make coal burning a bit cleaner. But if coal is dead in America, then the entire US economy is a dead man walking. Because there is simply NO replacement.
The fact of the matter is even though electricity generation in April 2012 reached a parity of Coal:NG = 1:1. By December 2012, the ratio was back to 1.60 : 1.0, with coal more prefered to NG.