A Black Carbon Crackdown Could Cool Temperatures

Black carbon, also known as soot, has an important role in global warming, especially in the Arctic. When it’s in the atmosphere, it traps heat, and when it falls on snow or ice, it speeds up melting. Curbing black carbon emissions could help slow down the planet’s warming

On the margins of the Paris climate conference, where governments made plans to keep global average temperatures below 2C (3.6F) by 2100, scientists and policymakers discussed other air pollutants that also contribute to global warming.

Emissions of carbon dioxide have a far greater role in climate change, but short-lived climate pollutants such as black carbon – soot – also speed up warming, especially in the Arctic. Black carbon is not a gas, but an aerosol, tiny particles produced from diesel trucks and cars, wildfires, agricultural burning, oil and gas production and shipping that are released into the atmosphere.

Black carbon is also causing the Earth’s climate to warm. A recent study found that black carbon is far more harmful to the climate than scientists once thought – its heat-trapping power is second only to carbon dioxide and it holds twice as much heat in the atmosphere than estimates made by the Intergovernmental Panel on Climate Change in 2007.

But as its name implies, short-lived climate pollutants such as black carbon don’t stay in the atmosphere for very long. Black carbon usually falls out of the air after about a week. If it lands on snow or ice, it darkens the surface and causes warming and melting by absorbing solar radiation instead of reflecting it. Consequently, the Arctic is very susceptible to warming that results from black carbon.

Because black carbon has a short lifetime, atmospheric concentrations can be quickly decreased by reducing emissions. Actions taken to reduce emissions could slow the rate of climate change in a —> Read More