Carbon-dioxide emissions from fossil fuels recorded their largest drop in 19 years last year, the federal government's chief clearinghouse for energy information reported, adding new fodder to the debate in Congress about how -- or whether -- to reduce greenhouse gases.
The Energy Department's Energy Information Administration (EIA) said Wednesday that carbon-dioxide output fell by 2.8 percent last year, the largest annual decline in energy-related carbon-dioxide emissions since 1990. EIA said last year's record-high oil prices and the start of the economic recession strongly contributed to the decline.
"There's a linear relation between oil consumption and carbon-dioxide emissions," said Perry Lindstrom, who lead the study at EIA. "Lower economic growth also has an effect on energy activity, and we saw that last year."
The new numbers emerge as the House Energy and Commerce Committee is on the verge of passing a climate-change bill that would impose strict new limits on greenhouse-gas emissions in an effort to reduce global warming. Energy-related carbon-dioxide emissions make up more than 80 percent of the nation's greenhouse-gas emissions, which are blamed by most scientists for the gradual warming of the world's surface.
The House is expected to pass the measure later this year, but its outlook in the Senate is uncertain.
Emissions from burning petroleum products, which includes those from refineries and power generation, declined last year by 6 percent. Vehicle emissions, which make up part of that figure, fell 5.2 percent after having risen continuously with the exception of a 1.3 percent decrease in 1991.
Some experts said the drop in emissions is no reason to abandon the congressional effort to reduce greenhouse gases.
"If opponents of the House climate-change bill want to reduce pollution through unemployment and the economic decline, then that's their choice," said Daniel J. Weiss, director of climate strategy at the liberal Center for American Progress.
Mr. Weiss said he would not be surprised if global-warming emissions remain stable this year, but predicted they would rebound next year along with the economy. Other climate scholars said the House's climate-change bill could itself prevent the economy from rebounding.
"The lesson to learn is that a decline in emissions is caused by a recession and the [House] bill aims to force a permanent recession," said Ben Lieberman, a senior energy and environment analyst at the conservative Heritage Foundation. "As long as the economy shrinks, so will carbon emissions."
Republicans and oil drillers have not endorsed the House climate-change bill and are not likely to change their stance given the EIA's findings.
"Today's news that energy-related carbon-dioxide emissions declined by 2.8 percent last year, the single largest decline in 19 years, is yet further evidence that the Democrats' cap-and-trade bill is straight out of 'Alice in Wonderland,' " said Rep. John Shadegg, Arizona Republican and member of the House Energy and Commerce Committee.
The American Petroleum Institute, the main lobby for the oil and gas industry, said the drop is "substantial" and that it expects emissions to continue to fall as refiners blend more ethanol with gasoline. Congress mandated in 2007 that more ethanol be used with gasoline to reduce greenhouse-gas emissions from cars.
Emissions fell in 2008 by 165 million metric tons.