Climate benefit for cutting soot, methane smaller than previous estimates

Terra Daily via SPX: Cutting the amount of short-lived, climate-warming emissions such as soot and methane in our skies won't limit global warming as much as previous studies have suggested, a new analysis shows. The study also found a comprehensive climate policy would produce more climate benefits by 2050 than if soot and methane were reduced alone.

"Cutting back only on soot and methane emissions will help the climate, but not as much as previously thought," said the study's lead author, climate researcher Steve Smith of the Department of Energy's Pacific Northwest National Laboratory. "If we want to stabilize the climate system, we need to focus on greenhouse gases such as carbon dioxide, nitrous oxide and methane. Concentrating on soot and methane alone is not likely to offer much of a shortcut."

…At least two studies have been published since 2010 that suggest reducing soot and methane would cut human-caused global temperature increases by half of a degree Celsius, or about 1 degree Fahrenheit, by 2050. International leaders took note and formed the Climate and Clean Air Coalition to Reduce Short-Lived Climate Pollutants in 2012.

Soot and methane are called short-term climate forcers because they only remain in the atmosphere for a relatively short time: a couple weeks for soot and up to a decade for methane. Meanwhile, the better-known climate change culprit carbon dioxide can stick around for 1,000-plus years.

Soot, also known as black carbon, is made of fine, carbon-based particles that are given off by car and truck tailpipes and wood stoves. Methane, the main component of natural gas, is released from leaking pipelines, coal mines, oil wells, cattle, rice paddies and landfills...

An outdoor vendor in India with a woodburning stove, shot by S zillayali, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license