Sixty to 80 percent of the coal, oil and gas reserves of publicly listed companies need to stay in the ground if the planet is to have a decent shot of keeping global warming to less than 2 degrees C above pre-industrial levels, the limit agreed to by world leaders. Extending McKibben's analogy, coal is the moonshine of fossil fuels — cheap, dirty and extremely dangerous. Oil is an off-brand whiskey. Natural gas is Grey Goose vodka — clean, refined and widely unobjectionable. It should appeal to free-market libertarians and left-leaning environmentalists alike. That's received wisdom, anyway. In actuality, natural gas simply poses a different range of threats. Gas may be just as hazardous as oil and coal.