Some 3 billion people worldwide are dependent on rudimentary stoves that burn wood, dung or coal. These account for about 20% of black-carbon emissions globally, as well as 2 million deaths annually from smoke inhalation. More-sophisticated stoves could dramatically reduce these figures, helping to combat climate change and improve public health.

Conventional stoves that burn solid fuels release black and brown carbon particles, along with gases that are implicated in climate warming (including carbon dioxide, ozone-producing gases and methane). As super-efficient absorbers of sunlight, these particles also affect agricultural crop yields.

Modern stoves with natural convection halve solid-fuel use, saving money and collection time. Forced-convection stoves equipped with a fan to increase combustion efficiency cut particulate emissions by 80–90%, black carbon by 60–90% and ozone-producing gases by 50–90% (J. Jetter et al. Environ. Sci. Technol. 46, 10827–10834; 2012; and A. Kar et al. Environ. Sci. Technol. 46, 2993–3000; 2012). Clean fuels, such as liquid petroleum gas, biogas or ethanol, would cut these emissions further.

The Global Alliance for Clean Cookstoves (www.cleancookstoves.org), which has almost 400 partners, including 36 countries, aims to have 100 million homes adopt clean and efficient stoves by 2020. It is developing financing tools for businesses and consumers to ensure that these user-friendly cooking stoves are affordable and available to all.

The Climate and Clean Air Coalition to Reduce Short-lived Climate Pollutants (www.unep.org/ccac) offers a new opportunity to promote energy-efficient stoves that specifically lower black-carbon emissions.