Mostly unnoticed amid the political brawl over climate change, America has undergone a quiet transformation in how and where it gets its energy during Barack Obama’s presidency, slicing the nation’s output of polluting gases that are warming Earth. As politicians tangled in the United States and on the world stage, the U.S. slowly but surely moved away from emissions-spewing coal and toward cleaner fuels like natural gas, nuclear, wind and solar. The shift has put…