A recent study found that black carbon, i.e. soot particles in smoke and smog, has roughly twice as much impact on global warming than previously thought, including estimates from the Intergovernmental Panel on Climate Change. “We were surprised by its potential contribution to climate,” said Sarah Doherty, an atmospheric scientist at the University of Washington (UW) and one of the four lead authors of the study, published in the Journal of Geophysical Research-Atmospheres.

Black carbon affects climate change in mid- to high-latitude regions, including the northern United States, Canada, Europe and Asia. It also affects rainfall patterns in the Asian monsoon. But there is hope that controlling these emissions could deliver immediate climate benefits, much faster than controlling carbon dioxide, the Washington statement said.

According to Doherty, some previous research has suggested that black carbon emissions, such as those from open burning of forests, crops and pastures, as well as from energy emissions in Southeast and East Asia, have been underestimated. Dark particles in the atmosphere also shade the Earth's surface and warm the atmosphere. Black carbon, which settles on snow and ice, darkens their surfaces and increases the absorption of sunlight, leading to faster melting. In addition, soot particles affect cloud formation in ways that can have either a cooling or warming effect.

The study reviewed previous research and added new research to quantify the sources of black carbon and better understand its overall impact on the climate. “In the absence of effective measures to reduce carbon dioxide emissions, the policy community is looking for other ways to help places like the Arctic, which is melting much faster than we expected,” Doherty added. (Co2AI)