Replacing traditional stoves in Africa and Asia with low-soot varieties would buy time in the fight against climate change. But the acceptability of such new stoves to the rural poor is an obstacle.
Black carbon has newly emerged as the second biggest contributor to climate change. It is responsible for an estimated 18 per cent of warming compared with 40 per cent for carbon dioxide.
Africa and Asia produce the most soot because of the use of traditional cooking stoves, which also pose health and other environmental risks.
Low-soot stoves would rapidly reduce black carbon levels as the soot remains in the atmosphere for just a few weeks compared with years for carbon dioxide. New stoves produce 90 per cent less soot and cost around US$20 to make.
But many rural people earn only US$2 a day and cannot afford the stoves. There are also concerns about whether the stoves will produce food as tasty as that cooked on traditional stoves.
Six types of cooker are being piloted in Indian villages.