Vox: One of the most promising climate-change stories of the last decade was the steep plunge in US carbon dioxide emissions after 2005. Before then, US emissions had been rising relentlessly for decades. Suddenly, they were falling.
That drop was partly due to the US fracking boom, which created a glut of cheap natural gas and spurred utilities to burn less coal for electricity. It was partly due to various clean-energy and efficiency measures. And it was partly making real progress on global warming....