From 2010 to 2011, CO2 emissions from fossil fuel combustion decreased by 2.5 % due to: (1) a decrease
in coal consumption, with increased natural gas consumption and a significant increase
in hydropower used; (2) a decrease
in transportation - related energy consumption due to higher fuel
costs, improvements
in fuel efficiency, and a reduction
in miles travelled; and (3) relatively mild winter conditions resulting
in an
overall decrease
in energy demand
in most sectors.