Should Methane Be Our First Line of Attack to Slow Global Heating?

By Penny Paugh

Scientist Peter Cox, speaking at the University of Exeter (United Kingdom), recently suggests that the way to win the battle with greenhouse gases is to lower methane emissions. In fact, curbing methane may be the best way to stem dangerous warming.

A map showing U.S. methane emissions by county from landfills. Reproduced from NREL.

Methane is released in many ways: landfills, livestock, rice paddies, coal mines, and gas pipeline leaks. Cox has studied how carbon dioxide and methane influence plant growth. He believes that feedback mechanisms of methane could have twice the expected punch on the earth’s climate. Increased carbon dioxide acts as a fertilizer, making forests and vegetation grow more; this would in turn allow the vegetation to absorb more CO2. Methane does not contribute this counter-effect. Also, curbing methane release would minimize the formation of tropospheric ozone, which damages plants.

While these facts are well-known, Cox is the first to calculate the balance between the two gases globally. He estimates that a 40 percent reduction in human-caused methane emissions would permit the release of an extra 500 gigatonnes of CO₂ – 33% more than previously thought – before we exceed a warming of  2 deg. C. He estimates that this would “lag” the current rate of global warming by up to fifteen years.

However, another expert on non-CO₂ greenhouse gases stated, “we need to accelerate our efforts on everything. It’s not methane or CO₂; it has to be both.”

Participants of the Planet Under Pressure meeting hope the United Nations Earth Summit 2012 in June will put environmental security at the heart of world diplomacy.

Reference

Pearce, F. (March 28, 2012) Methane Cuts Could Delay Climate Change by 15 Years,” New Scientist, retrieved from http://www.newscientist.com/article/mg21328583.800-methane-cuts-could-delay-climate-change-by-15-years.html