[randolph]

What I meant was that the effect of methane in the atmosphere is near 50% of the warming contributed by greenhouse gases not the amount of methane in the atmosphere.

From The Telegraph UK.
"Methane is mostly emitted by agriculture, most famously from cows burping Photo: PAUL WINTER/GETTY IMAGES

Already, scientists consider methane as the second most damaging greenhouse gas produced by human activity after carbon dioxide. It is mostly emitted by agriculture, most famously from cows burping but also from ploughing soil and allowing vegetable matter to rot. Landfill is also a major cause of methane and the burning of coal and natural gas.

Before it was thought every tonne of methane was around 25 times more damaging to the atmosphere than every tonne of carbon dioxide.

Related Articles

*
EU summit: climate change and presidency top agenda
*
Britain will not sign up to a weak deal at Copenhagen
*
Putting biomass into the equation
*
Obesity threat to individuals and planet
*
Amazon rainforest at risk of ecological 'catastrophe'
*
Barack Obama 'must act now' to tackle climate change

However a new study by the Nasa Goddard Institute for Space Studies has found methane is 33 times more damaging if the effects of interaction with other airborne pollutants is included.

The report, published in Science, found that the warming effects of methane are increased through its interaction with aerosols like sulphate molecules.

The finding has implications for any climate change deal decided by the UN in Copenhagen in December.

At the moment targets are focused on cutting carbon dioxide but scientists are now arguing for more emphasis on cutting other greenhouse gases as well -especially because methane breaks down more quickly in the atmosphere so cuts will have a more immediate effect.

Dr Chris Huntingford, of the Centre for Ecology & Hydrology, said the study could influence climate change negotiations."

"This is an excellent analysis demonstrating that methane emissions have the potential to add more future warming than hereto realised. This new research complements the well-established result that carbon dioxide emissions have been responsible for a large fraction of the global warming observed since pre-industrial times," he said.

"There is a requirement to distil this more complete understanding of how the many different atmospheric gases interact, both between themselves and with humans. Policy decisions must account for such interactions and links to emissions of carbon dioxide, methane, and atmospheric aerosols."