Blog post by Astrid Caldas, climate change and wildlife scientist with Defenders of Wildlife. This blog originally appeared on the Huffington Post.
You have probably heard about melting Arctic ice and the drastic decrease in glacier size. You may have seen it yourself during a trip to a favorite spot, and mourned the loss of beautiful snow covered views. And while you may be aware that the increase in greenhouse gases is to blame, at least in large part, for our planet’s warming, you may not realize that a substance called black carbon is an accomplice, affecting everything from polar bear habitat in the Arctic to glacial-fed drinking water in the Himalayas. A recent peer-reviewed study found that “Most of the change in snow and ice cover — about 90 percent — is from aerosols. Black carbon alone contributes at least 30 percent of this sum.”
Black carbon is an aerosol produced during poor combustion of carbon-based fuels (as opposed to carbon dioxide, which is produced in all circumstances), and together with organic carbon is one the major components in soot. Sources include diesel engines in various types of vehicles, furnaces, cook stoves, and forest fires, as well as some industrial processes. Some 25% to 35% of emissions occur in China and India (from combustion of wood, coal, and other fuels for household uses), whereas Europe, North America and eastern European countries emit about 13% of all black carbon, mostly from contained combustion.
Black carbon absorbs visible light and transfers the energy to the atmosphere, warming it. While carbon dioxide can stay in the atmosphere for 100 years, black carbon has a short atmospheric lifetime, making its effects more concentrated near the areas where it is emitted, especially in terms of atmospheric warming and health issues due to inhalation. It settles quickly from the atmosphere, and when it lands on snow and ice, the darkened snow and ice absorb more heat and melt more quickly. Because most emissions occur above 40⁰N, where they are likely to be transported to the Arctic (see Princeton University Report), black carbon has been linked to the melting of Arctic ice and Himalayan glaciers.
What can we do? Read the full blog on the Huffington Post to learn how we can address black carbon emissions in what may be the fastest, cheapest way to cool the planet.