While most climate change mitigation efforts have focused on carbon dioxide, methane's warming potential is about 28 times greater on a 100-year horizon, and its lifespan in the atmosphere is much shorter.
Breeding rice to require less flooding, altering feed for livestock to lessen intestinal processes that create methane, promoting less meat-intensive diets and deploying more farm bio-digesters can be possible solutions for reducing the polluting gas from food production, a study has shown.
‘Unlike carbon dioxide, the bulk of methane emissions are human-driven. Chief among those are agricultural sources such as livestock.’
In the journals Earth System Science Data and Environmental Research Letters published on Monday, a group of international researchers reported that emissions of methane have jumped dramatically in recent years and are approaching an internationally recognised worst-case scenario for greenhouse gas emissions, thus speeding sea level rise and more extreme weather.
"Methane presents the best opportunity to slow climate change quickly," said Rob Jackson, the papers' co-author and chair of Stanford University's Earth System Science Department. "Carbon dioxide has a longer reach, but methane strikes faster".
Unlike carbon dioxide, the bulk of methane emissions are human-driven. Chief among those, according to the analysis, are agricultural sources such as livestock, which emit methane through bodily functions and manure, and rice fields, which emit methane when flooded.
Natural sources of methane, which account for 40 percent of all methane emissions, are more uncertain than human-driven ones, which are responsible for 60 percent of all methane emissions globally. Examples include methane leaking out of natural faults and seeping on the ocean floor, and the potential for increased emissions as permafrost warms.
Besides efforts proposed to curb emissions from agriculture, the researchers said opportunities in other areas include venting and flaring of methane in coal mines, detecting and removing natural gas leaks from oil and gas drilling operations and covering landfills to capture methane emissions.
"We still need to cut carbon dioxide emissions," Jackson said, "but cutting methane provides complementary benefits for climate, economies and human health".