SOURCE: Inside Climate News

DATE: February 15, 2019

SNIP: When soot from fossil fuel combustion and wildfires drifts onto the Arctic ice and snow, it helps feed a spiraling cycle of warming, melting ice and rising sea level.

New research carried out at remote locations across the Arctic shows that most of the soot—also known as black carbon—is coming from fossil fuel sources such as coal power plants, cars and trucks and factories. The findings could help countries begin to control this climate pollutant.

“Some people think it’s biofuels and wildfires, but our main takeaway is that fossil fuels are the main source of black carbon in the Arctic,” said Patrik Winiger of Vrije Universiteit Amsterdam, the lead author of a study published today in the journal Science Advances.

His team found that about 70 percent of the black carbon in the Arctic currently comes from fossil fuel burning in Northern countries. They tracked changes in black carbon levels in the atmosphere through the seasons over five years and used chemical analyses to determine the pollution’s origins.

During winters, they found that emissions from fossil fuel burning made up the majority of black carbon accumulations.

During the summer, when overall black carbon concentrations are lower, emissions from wildfires and agricultural burning were bigger sources.

Black carbon typically stays aloft for only a few days to weeks before falling. While airborne, it is a short-lived climate pollutant that is many times more potent than carbon dioxide at warming the atmosphere, though it has a far shorter lifespan.

Once it falls, black carbon darkens the surface of the ice and snow, where it absorbs energy from sunlight. That can cause melting on the surface while also reducing how well the ice reflects solar radiation back into space.