Research measures 'black carbon' threat

Every evening, hundreds of millions of Indian women hover over crude stoves making dinner for their families. They feed the flames with polluting fuels like kerosene or cow dung, and breathe the acrid smoke wafting from the fires.

The smoke, containing high concentrations of tiny particles known as black carbon, is responsible for premature deaths from cancer and other diseases and is causing or exacerbating environmental problems from climate change and glacial melt to falling crop yields.

When you add up all the tiny stoves, the result comes close to catastrophic. And yet black carbon is largely unregulated and its costs unmeasured, creating a barrier to earmarking public and donor funds for underwriting the use of cleaner cookers.