For too long, climate diplomacy has focused on carbon dioxide. But at least 40 percent of global warming can be blamed on shorter-lived pollutants, which also cause disease and damage crops in developing states. Reining in pollution would thus accomplish two goals, while finally getting countries such as China and India into the climate-change business.
Most initiatives to slow global warming involve reducing carbon dioxide emissions. Little attention has been given to reducing emissions of the light-absorbing particles known as "black carbon" or the gases that form ozone--even though doing so would be easier and cheaper and have a more immediate effect.