Narrator: This is Science Today. Efforts to reduce global warming often focus on the reduction of carbon dioxide, but half of the problem is caused by non-carbon dioxide gases and pollutants, including black carbon. Climate scientist V. Ramanathan of the University of California, San Diego's Scripps Institution of Oceanography, explains that a major source of black carbon is cooking with firewood, cow dung and crop residues in the developing world.
Ramanathan: About 3 billion on [the] planet have no access to fossil fuels. Still they use these substances, firewood, cow dung for cooking and heating. And we have better cooking technologies, better heating technologies. If only we could find a way to provide these to these 3 billion. They can have an immediate impact on climate, we can save at least 2 million lives every year, and they can save millions of tons of crop damage. So here is a solution available to us and we can do that today, not years from now.Narrator: For Science Today, I'm Larissa Branin.