Carbon dioxide buildup quickens

WASHINGTON – Just days after a Nobel Prize was awarded for global warming work, an alarming new study finds that carbon dioxide in the atmosphere is increasing faster than expected.

Carbon dioxide emissions were 35 percent higher in 2006 than in 1990, a much faster growth rate than anticipated, researchers led by Josep G. Canadell, of Australia’s Commonwealth Scientific and Industrial Research Organization, report in today’s edition of Proceedings of the National Academy of Sciences.

Increased industrial use of fossil fuels coupled with a decline in the gas absorbed by the oceans and land were listed as causes of the increase.

Carbon dioxide is the leading “greenhouse gas,” so named because accumulation in the atmosphere can help trap heat from the sun, causing potentially dangerous warming.

While most atmospheric scientists accept the idea, finding ways to reduce greenhouse gas emissions has been a political problem because of potential effects on the economy.

Kevin Trenberth of the climate analysis section of the National Center for Atmospheric Research in Boulder, Colo., noted that carbon dioxide is not the whole story. Methane emissions have declined, so total greenhouse gases are not increasing as much as carbon dioxide alone. Also, he added, other pollution plays a role by cooling.

There are changes from year to year in the fraction of the atmosphere made up of carbon dioxide and the question is whether this increase is transient or will be sustained, he said.