Chapter 01 · Climate & transitionClimate & Greenhouse Gas Emissions
Black carbon
Definition
A particulate aerosol formed by the incomplete combustion of fossil fuels, biofuels and biomass — the dark component of soot. Black carbon warms the climate directly by absorbing sunlight in the atmosphere and indirectly by darkening snow and ice surfaces, reducing their reflectivity. A comprehensive international assessment found it ranks second behind carbon dioxide as a cause of human-made global warming.
References
Black carbon as short-lived "super pollutant"; 70%-by-2030 reduction target; health–climate coupling.
Second-largest human cause of warming (Bond et al./IGAC assessment); sources; climate influence.
Overview
What it means
Black carbon is a "short-lived climate pollutant": it remains airborne for days to weeks rather than centuries, so cutting emissions produces climate benefits quickly. Sources include diesel engines, household solid-fuel cookstoves, agricultural burning, wildfires and some industrial processes.
Because it also causes severe respiratory and cardiovascular harm, mitigation delivers coupled climate and health gains — the founding logic of the Climate and Clean Air Coalition, which targets reductions of up to 70% in black carbon by 2030 relative to 2010.
How it is used
Policy focuses on diesel particulate filters, clean cooking, brick-kiln and agricultural-burning controls, and Arctic shipping rules, since deposition on Arctic ice amplifies regional warming. Black carbon is reported in air-pollution inventories rather than GHG inventories, a governance boundary that shapes who regulates it.
Why it matters
Black carbon offers one of the fastest available levers to slow near-term warming — particularly in the Arctic — while immediately improving air quality for billions of people.