US carbon dioxide emissions resulting from energy use during the first quarter of 2012 were the lowest in two decades for any January-March period, according to US Energy Information Administration figures.
The country’s CO2 emissions from energy consumption totaled 1,340 million metric tons during the first quarter of 2012, down nearly eight percent from a year, according to the EIA’s June Monthly Energy Review.
Normally, CO2 emissions during the year are highest in the first quarter because of strong demand for heat produced by fossil fuels. However, such emissions during the first quarter in 2012 were low due to a combination of the warm winter that reduced heating demand, a sharp decline in the amount of total electricity generated from burning coal, and lower gasoline use, the EIA says. This year saw the warmest March ever recorded in much of the United States.
CO2 emissions from coal were down 18 percent year-on-year to 387 million metric tons in the January-March 2012 period. Those was the lowest-first quarter CO2 emissions from coal since 1983 and the lowest for any quarter since April-June 1986. The decline in coal-related emissions is due mainly to utilities using less coal for electricity generation as they burned more low-priced natural gas, the EIA says.
About 90 percent of the energy-related CO2 emissions from coal came from the electric power sector. Coal has the highest carbon intensity among major fossil fuels, resulting in coal-fired plants having the highest output rate of CO2 per kWh, the EIA says.
The share of electricity generated from coal-fired power plants dropped to 34 percent in March, the lowest level in at least 39 years, the EIA figures showed.
Coal generation decreased 29 billion kilowatt hours from March 2011 to March 2012, while natural generation increased 27 billion kilowatt hours during the same period.
Natural gas prices were near 10-year lows this winter, causing generators in states such as Ohio and Pennsylvania to increase their dispatch of natural gas-fired plants, EIA said. Newer natural gas-fired plants also operate more efficiently than older, coal-fired units, which increases the competitiveness of natural gas relative to coal, EIA said.