U.S., 5 Nations to Cut Methane, Soot Emissions

The United States and five other countries agreed this week to fund an effort to cut emissions of methane, soot and other pollutants to start to slow the rate of human-induced climate change.

The effort, for which the nations pledged $27 million, will use existing technologies such as improved cook stoves and capturing methane from landfills in an effort scientists say could slow global mean warming 0.5 degrees C by 2050.

The other countries who have pledged to join the fight include Canada, Mexico, Bangladesh, Sweden and Ghana.

The program was spurred in part by a recent paper in Science co-authored by Drew Shindell of NASA’s Goddard Institute for Space Studies, affiliated with the Earth Institute, and a June 2011 report from the UN Environment Programme, chaired by Shindell, and the World Meteorological Organization. (A recent story about the report appears on the Earth Institute web site, and a related piece on the State of the Planet blog.)

“We’ve shown that while these emission controls cannot substitute for reductions in carbon dioxide emissions, they can provide societal benefits with economic valuations that usually exceed the cost of the emissions reductions, in many cases several times over,” Shindell said. “We’ve provided a list of the most practical and beneficial actions that could be taken, and it’s gratifying to see policy-makers respond so quickly to try and bring about these emission reductions.”

The scientists project that these kinds of efforts can not only slow global warming, but also prevent between 700,000 and 4.7 million premature deaths each year and increase global crop yields by up to 135 million tons per season.

Climate change “impacts global security, the global economy, global food and water supplies, and the health and well-being of people everywhere,” Secretary of State Hillary Clinton said at a formal announcement of the project at the U.S. State Department Thursday. “And we know that in the principal effort necessary to reduce the effects of carbon dioxide, the world has not yet done enough. So, when we discover effective and affordable ways to reduce global warming – not just a little, but by a lot – it is a call to action.”

The technology for tackling these pollutants is already out there: installing filters for diesel engines, using more efficient cookstoves, curbing the open burning of agricultural waste, modernizing brick kilns, and capturing methane released by landfills, coal mines, oil and gas wells, leaky pipelines, wastewater treatment plants and rice paddies.

The effort, researchers say, is not a substitute for dealing with the larger problem of carbon dioxide emissions. The pollutants that are the focus of the new initiative are relatively short-lived, while CO2 persists in the atmosphere for hundreds of years. And given the current debates over climate change here and abroad, combatting carbon dioxide emissions has proven to be a politically and economically thorny problem.

The amount of CO2 in the atmosphere has increased steadily over the past century from a historical average of 300 parts per million to 393 ppm today; the world has warmed by about 0.8 degrees C from pre-industrial levels.

Climate scientists suggest a temperature increase of beyond 2 degrees C (3.6 degrees F) could have a major impact on the climate, changing patterns of precipitation, causing more frequent droughts and extreme weather, and causing glaciers and ice sheets to melt more quickly. The additional melting, along with expansion from warmer temperatures, will add to already rising sea levels.

NASA has posted an interview with Shindell about the study. He led the effort, which involved some 70 scientists.