"Although GDP increased by 2.8% in 2012, energy consumption fell by 2.4% (2.4 quadrillion Btu) in that same year—the result was a 5.1% decline in energy use per dollar of GDP," the EIA said.
The decline in energy consumption was driven by increased natural gas usage for power generation and reduced energy consumption in the transportation sector.
The big-picture impact was that the US emitted less than 5.3 billion metric tons of CO2 in 2012, 3.8% less than it did the previous year.
Reduced energy consumption in the transportation sector accounted for more than 20% of the total emissions reductions, as vehicle-miles traveled remained flat in 2012.
Carbon emissions from electricity fell by 6.1% last year as natural gas replaced coal as the fuel of choice.
The carbon intensity of US electricity production fell 13% from 2007 to 2012, mainly because of the shift to more natural gas generation.
Meanwhile, warm weather during the first quarter of 2012 reduced energy consumption in the residential sector by 2.4%.
