Black carbon casts a deadly shadow worldwide, from the sprawl of Los Angeles, to the slums of Mumbai, to the Arctic ice that sustains polar bears and other wildlife. But quick action to cut black carbon can slow Arctic melting, fight global warming and save lives.
The chief culprit in global warming is carbon dioxide (CO2). But recent studies show that black carbon—microscopic airborne particles commonly known as soot—is also a big factor. According to a recent study, black carbon may account for as much as half of Arctic warming. Along with deep cuts in CO2, curbing black carbon is crucial for slowing Arctic and global warming, and for averting catastrophic tipping points such as the melting of sea ice and the Greenland ice sheet.
Black carbon comes from diesel engines, industrial smokestacks and residential cooking and heating stoves. Most black carbon that falls in the Arctic comes from North America, Europe and Asia. Because black carbon air pollution is also a leading cause of respiratory illness and death, controlling emissions will save lives and improve health around the world. In India alone, black carbon-laden indoor smoke is responsible for over 400,000 premature deaths annually, mostly of women and children.
The direct absorption of sunlight by black carbon heats the atmosphere. When black carbon falls on snow and ice, it reduces reflectivity and speeds up melting. The good news: Because black carbon stays in the atmosphere for only days or weeks, moving quickly to expand existing technology can be an effective rapid response to slow warming, buying critical time to achieve reductions in CO2.
The U.S. and Europe must lead on this issue by committing to stricter standards at home for diesel engines and other sources of black carbon pollution, and by committing to increased financial and technological assistance to the developing world to reduce black carbon pollution from diesel, home cooking and heating and other sources.