U.S. Energy-Related Carbon Emissions Declining

(Source: U.S. Energy Information Administration, Monthly Energy Review)

U.S. carbon emissions last year were at their lowest since 1994 (5.3 billion cubic tones) and are continuing to decline according to the U.S. Energy Information Administration. Since 2007, CO₂ emissions have declined every year with the exception of 2010. The main reason for the trend is the transition from coal to natural gas; EIA also names several less important factors.

The largest drop in emissions in 2012 came from coal, which is used almost exclusively for electricity generation (see figure below). During 2012, particularly in the spring and early summer, low natural gas prices led to competition between natural gas- and coal-fired electric power generators. Lower natural gas prices resulted in reduced levels of coal generation, and increased natural gas generation—a less carbon-intensive fuel for power generation, which shifted power generation from the most carbon-intensive fossil fuel (coal) to the least carbon-intensive fossil fuel (natural gas).

Other factors contributing to the lower emissions include decreased demand for transportation fuels and mild winter temperatures that reduced demand for heating. The warm winter months during 2012 (particularly in the first quarter) more than offset a slight increase in cooling degree days during the summer months.

EIA recently published preliminary data for January-December 2012 in the March 2013 edition of the Monthly Energy Review, which includes statistics covering all aspects of energy. EIA will publish a full analysis of 2012 energy-related CO₂ emissions later this year.