Climate Central: Bitter cold and a chill wind inevitably mean the heat gets cranked up inside. And as the polar vortex parked itself over Canada and the northeastern U.S. to end 2013, that's what people did.
Largely as a result of trying to keep warm from that Arctic chill, carbon dioxide emitted from burning energy in the U.S. increased 2.5 percent in 2013 over the previous year, according to the U.S. Energy Information Administration's annual CO2 emissions report, released Tuesday.
Only three other years...