"A U.S.-led drive to reduce soot and other heat-trapping air pollutants worldwide is less promising than hoped as a new front in the fight against climate change, according to a study published on Monday."

"Frustrated by failure to agree a broad international deal to limit global warming, about 30 nations have joined the U.S. initiative to limit short-lived air pollutants as a new way to curb temperature rises, protect health and aid crop growth.

But the report said that extra measures to reduce such pollutants, led by soot and methane, would cut temperature rises by only 0.16 degree Celsius (0.29 Fahrenheit) by 2050, far less than some estimates that the benefits could be 0.5C (0.9F)."

Alister Doyle reports for Reuters August 13, 2013. [2]