Fracking has done more to reduce US carbon emissions than anything that solar or wind could currently hope to do.
Carbon-dioxide emissions in the United States have dropped to their lowest level in 20 years. Estimating on the basis of data from the US Energy Information Agency (EIA) from the first five months of 2012, this year’s expected CO2 emissions have declined by more than 800 million tons, or 14%, from their peak in 2007.
The cause is an unprecedented switch to natural gas, which emits 45% less carbon per energy unit. The US used to generate about half its electricity from coal, and roughly 20% from gas. Over the past five years, those numbers have changed, first slowly and now dramatically: in April of this year, coal’s share in power generation plummeted to just 32%, on par with gas.
... The reduction is even more impressive when one considers that 57 million additional energy consumers were added to the US population over the past two decades. Indeed, US carbon emissions have dropped some 20% per capita, and are now at their lowest level since Dwight D. Eisenhower left the White House in 1961.
David Victor, an energy expert at the University of California, San Diego, estimates that the shift from coal to natural gas has reduced US emissions by 400-500 megatonnes (Mt) of CO2 per year. To put that number in perspective, it is about twice the total effect of the Kyoto Protocol on carbon emissions in the rest of the world, including the European Union.