The fracking innovation was not intended as climate policy, but simply as a way to make the United States more energy independent and richer. But it also turned out to have a huge climate change benefit, because gas became cheaper than coal. Crucially, gas emits about half the carbon dioxide of coal. Making gas cheaper than coal has shifted a large part of US electricity production from coal to gas. This is the main reason why the United States has seen the largest reduction in carbon dioxide emissions of any nation over the past decade.
