Atmospheric Methane Levels Leveling Off - Possible Link To Fires, Oil Industry - AFP

[hatrack]

Levels of atmospheric methane, an influential greenhouse gas, have stayed nearly flat for the past seven years, following a rise that spanned at least two decades, researchers say. This finding indicates that methane may no longer be as large a global warming threat as previously thought, and it provides evidence that methane levels can be controlled.

Scientists also found that pulses of increased methane were paralleled by increases of ethane, a gas emitted during fires. This is further evidence, they say, that methane is formed during biomass burning and that large-scale fires can be a big source of atmospheric methane.

Professors Sherwood Rowland and Donald Blake of the University of California, Irvine, and researchers Isobel Simpson and Simone Meinardi, say that one reason for the slowdown in the growth of methane concentration may be leak-preventing repairs made to oil and gas pipelines and storage facilities, which can release methane into the atmosphere. Other reasons may include slower growth or actual decrease in methane emissions from coal mining, rice paddies, and natural gas production, they say.

"If one really tightens emissions, the amount of methane in the atmosphere 10 years from now could be less than it is today. 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," said Rowland, a co-recipient of the 1995 Nobel Prize for discovering that chlorofluorocarbons in such products as aerosol sprays and coolants were damaging the Earth's protective ozone layer. The research will be published 23 November in Geophysical Research Letters. Methane, the main ingredient of natural gas, warms the atmosphere through the greenhouse effect and helps form ozone, a component of smog. Since the Industrial Revolution in the late 1700s, atmospheric methane has more than doubled. About two-thirds of methane emissions can be traced to human activities, such as fossil-fuel extraction, rice paddies, landfills, and cattle farming.

EDIT

http://www.terradaily.com/reports/Seven_Year_Stabilization_Of_Methane_May_Slow_Global_Warming_999.html

[Javaman]

1. That is of course until the permafrost and the greenland ice pact start

melting in ernest.