Over 3 billion people in low- and middle-income countries rely on solid fuels (wood, animal dung, charcoal, crop wastes and coal) burned in inefficient and highly polluting stoves for cooking and heating, currently resulting in some 4 million premature deaths annually. These same household pollutants, such as black carbon, also have climate warming effects.
More efficient stoves and cleaner fuels that meet WHO indoor air quality guidelines have the potential to avert millions of deaths each year caused by household air pollution, while also reducing emissions that impact climate change.
Among the available technologies, cleaner fuels such as biogas, ethanol, LPG, and natural gas along with electricity are the best alternatives to solid fuels for reaching WHO air quality guideline levels for household air pollution.
Advanced biomass stoves can offer an important transition technology that reduces emissions levels common to traditional biomass stoves. Nevertheless, many improved biomass cookstoves still do not meet WHO air quality guideline levels, despite their improved fuel efficiency and somewhat reduced emissions of particulate matter. Use of unprocessed coal or kerosene stoves is meanwhile discouraged by the guidelines altogether due to their very high level of air pollution emissions.
Other benefits of more efficient cooking appliances include fuel cost or collection savings, injury reduction, and better temperature and indoor environment control. Cleaner cookstoves and fuels have the potential to achieve gains in health, gender equity, and sustainability across the developing world.