CAMBRIDGE – Against all expectations, US emissions of carbon dioxide into the atmosphere, since peaking in 2007, have fallen by 12% as of 2012, back to 1995 levels. The primary reason, in a word, is “fracking.” Or, in 11 words: horizontal drilling and hydraulic fracturing to recover deposits of shale gas.
No other factor comes close to providing a plausible explanation. Unlike the European Union, the US never ratified the Kyoto Protocol, in which participating countries committed to cut CO2 emissions by roughly 5%, relative to 1990 levels, by 2012. Nor is America’s continued emissions reduction a side effect of lower economic activity: While the US economy peaked in late 2007, the same time as emissions, the recession ended in June 2009 and GDP growth since then, though inadequate, has been substantially higher than in Europe. Yet US emissions have continued to fall, while EU emissions began to rise again after 2009.