Simply replace older cookstoves with more efficient new models that function essentially similarly but burn fuel more efficiently, resulting in less smoke and soot, as well as use less fuel, that's the reasoning. I've made the case many times here on TreeHugger, and major international aid programs are underway, investing millions of dollars to spread newer, cleaner technology.
But, if a new survey of Bangladeshi women, published in Proceedings of the National Academy of Sciences, is more widely applicable then there's a huge uphill climb ahead for proponents of the cleaner cookstove climate and health fix.
It seems that even though 94% of Bangladeshi women surveyed know that the cooking smoke is a serious health hazard indoors (remember it's overwhelmingly women exposed to the smoke), they'd prefer to stick with traditional stoves and spend money on other aspects of their lives.
If given the option of new clean cookstove or a cash subsidy, they'd take the cash and spend it on "doctors, schools, electricity, clean water, latrines, seeds for planting, and structures to protect their land from flooding."
Currently 98% of Bangladeshis use traditional cookstoves, fueled by a mix of wood and agricultural waste, and dried animal dung. The smoke from these stoves causes 50,000 premature deaths annually, part of 2 million premature deaths worldwide attributed to indoor air pollution. Outside the home, the black carbon soot from these stoves (as well as from industrial sources and older diesel engines) is a significant component of global warming, as well as increasing the rate of glacier melting as the particles settle on the ice reducing its albedo.
The survey found that even when the clean cookstoves were offered at a 50% subsidy, the rate of adoption only increased 12% for ones which burned fuel more efficiently and 5% for ones with a chimney. At full price the adoption rate was a very meagre 2-5%.
At least in Bangladesh, the draw of electricity, clean water, and a latrine (let alone what we in the wealthy world would consider adequate plumbing) are far bigger draws than either the threat of health problems from indoor air pollution or climate change—both, in the moment, theoretical problems with the effects felt non-immediately.