Black carbon is a byproduct of poor or incomplete combustion and is estimated to contribute the equivalent of 25 to 50% of carbon dioxide warming globally. It also has local climatic effects. In South Asia, for example, black carbon disrupts annual monsoons and accelerates the melting of the Himalayan-Tibetan glaciers, threatening water availability and food security for millions of people. These problems are compounded by crop damage from ozone partly produced by cookstove emissions, and from surface dimming that results as airborne black carbon intercepts sunlight.
Since the atmospheric lifetime of black carbon is only a few days, reducing black carbon emissions can bring about a rapid climate response in a short amount of time. Their reduction also produces multiple benefits in areas close to emission sources. Replacing traditional cookstoves more efficient ones can have a significant impact. Modern cookstoves emit less greenhouse gases and also reduce fuel use by 30-60% and black carbon emissions by 50-90%.
Improving domestic heating that uses solid fuel burning (primarily wood and coal) in both developed and developing countries is another way to reduce black carbon. Although smaller in gross terms compared to domestic cooking, heating emissions tend to occur quite close to cryosphere (snow and ice) regions. This intensifies the regional climate impacts as black carbon soot falling on white ice and snow decreases their reflectivity and contributes significantly to melting of land glaciers and sea ice. In addition, heating emissions are one of the few sources that is projected to increase globally, as more households turn to burning wood for warmth.
The household cooking and heating sector represents one of the best opportunities for the Coalition to affect quick and significant measures to reduce SLCPs and meet the climate goals of the global community while achieving other health, gender, environmental, and development benefits.