Niveau Broeikasgas Methaan Stabiliseert

" U.S. study suggests levels of atmospheric methane have been nearly flat for seven years, following a rise that spanned at least two decades.

University of California-Irvine researchers say their finding indicates methane might no longer be as large a global warming threat as previously thought.

Professors F. Sherwood Rowland and Donald Blake, along with researchers Isobel Simpson and Simone Meinardi, believe one reason for the slowdown in methane concentration growth might be leak-preventing repairs made to oil and gas lines and storage facilities. Other reasons may include a slower growth or decrease in methane emissions from coal mining and natural gas production.

"If one really tightens emissions, the amount of methane in the atmosphere 10 years from now could be less than it is today," said Rowland, co-recipient of a 1995 Nobel Prize for discovering that chlorofluorocarbons in products such as aerosol sprays and coolants were damaging the Earth's ozone layer. "We will gain some ground on global warming if methane is not as large a contributor in the future as it has been in the past century."

The methane research appeared in the Nov. 23 online edition of Geophysical Research Letters."

Bron: www.climateark.org