Black Carbon Second-Biggest Human Contributor to Climate Change: Study

A new study indicates that black carbon, the soot produced from burning wood and diesel exhaust, is the second leading contributor of global warming.

The study, released Tuesday by a team of international researchers, reveals that black carbon's impact on the climate is twice as much as estimated in the 2007 assessment by the United Nations Intergovernmental Panel on Climate Change.

During that time, black carbon was ranked as the third-largest climate pollutant, only next to carbon dioxide and methane. But the new study has moved black carbon up in the ranking and placed it in second position, pushing methane into the third spot as the major contributor to climate change, reports Reuters.

Black carbon lasts in the atmosphere only for a few days as against carbon dioxide, which can remain in the Earth's atmosphere for decades. But the soot's greenhouse impact is about two-thirds the effect of carbon dioxide, according to the new assessment.

It also stated that black carbon has caused rapid global warming in the northern United States, Canada, northern Europe and northern Asia, and could affect rainfall patterns, the Reuters report said.

Amid growing concerns over increasing global temperatures, experts believe there is some opportunity to curb warming by reducing black carbon emissions. They suggest that cutting down on black carbon emissions might help in cooling the climate.

The findings of the study came on the same day as NASA released a report announcing that 2012 was one of the warmest years on record since 1880. The new analysis showed that the average global temperature has increased about 1.4 degrees F (0.8 C) since 1880.

The findings of the study, "Bounding the role of black carbon in the climate system: A scientific assessment", appear in The Journal of Geophysical Research-Atmospheres.