US carbon dioxide emissions generated from energy consumption and production fell 3.8 percent in 2012 to 5,290 million metric tons, reaching their lowest level since 1994, according to a report from the Energy Information Administration.
Annual energy-related emissions were 5,498 million metric tons in 2011, the EIA says in its report.
Energy intensity — the energy measured in Btu per dollar of GDP — fell by 5.1 percent, driving the decline in emissions even as the US economy grew 2.8 in 2012. Half of the overall energy decline was from the residential sector, which needed less heating due to a warm first quarter of the year.
Typically, the first quarter of the year marks the high point for CO2 emissions.
This year, a combination of a warm winter that reduced heating demand, a sharp decline in the amount of total electricity generated from burning coal and lower gasoline use pushed emissions in the first quarter to the lowest in two decades from any January-March period. By the end of March, cumulative heating degree days were about 19 percent below the 10-year normal and 22 percent below 2011, the EIA says.
Energy-related emissions have fallen in five of the past seven years and dropped in 2012 despite a 0.7 percent increase in population, the EIA says.
An EIA report released in May 2013 found CO2 emissions from energy rose in 18 states and fell in 32 between 2000 and 2010. Texas had the greatest absolute decline of 58.8 million metric tons.
Despite the 8.3 percent drop in emissions, Texas still led the US states in CO2 emissions from energy with 663 million metric tons in 2010, followed by California and Pennsylvania. Nearly half of Texas’ emissions came from petroleum fuels in 2010, according to the EIA data.
California produced about 370 million metric tons of CO2 in 2010 with about two-thirds of it generated from petroleum fuels and a third from natural gas.