Climate change: Soot's role underestimated

 

 
The burning of wood is a major source of black carbon the world over.
 

Black carbon, or soot, is making a much larger contribution to global warming than previously recognised, according to research.

Scientists say that particles from diesel engines and wood burning could be

having twice as much warming effect as assessed in past estimates.

They say it ranks second only to carbon dioxide as the most important

climate-warming agent.

The research is in the Journal of Geophysical Research-Atmospheres.

Black carbon aerosols have been known to warm the atmosphere for many years

by absorbing sunlight. They also speed the melting of ice and snow.

This new study concludes the dark particles are having a warming effect

approximately two thirds that of carbon dioxide, and greater than methane.

"The large conclusion is that forcing due to black

carbon in the atmosphere is larger," lead author Sarah Doherty told BBC News.

"The value the IPCC gave in their 4th assessment report in 2007 is half of

what we are presenting in this report - it's a little bit shocking,"

The researchers say black carbon emissions in Europe and North America have