Black carbon

Chemically, black carbon (BC) is a component of fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter). Black carbon consists of pure carbon in several linked forms. It is formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is emitted in both anthropogenic and naturally occurring soot.

Black carbon causes human morbidity and premature mortality.

In climatology, black carbon is a climate forcing agent. Black carbon warms the Earth by absorbing sunlight and heating the atmosphere and by reducing albedo when deposited on snow and ice (direct effects) and indirectly by interaction with clouds, with the total forcing of 1.1 W/m². Black carbon stays in the atmosphere for only several days to weeks, whereas carbon dioxide (CO₂) has an atmospheric lifetime of more than 100 years.

The term black carbon is also used in soil sciences and geology, referring either to deposited atmospheric black carbon or to directly incorporated black carbon from vegetation fires. Especially in the tropics, black carbon in soils significantly contributes to fertility as it is able to absorb important plant nutrients.

The term black carbon was coined by Tihomir Novakov, referred to as "the godfather of black carbon studies" by James Hansen, in the 1970s. Smoke or soot was the first pollutant to be recognized as having significant environmental impact yet one of the last to be studied by the contemporary atmospheric research community. Faraday recognized that soot was composed of carbon and that it was produced by the incomplete combustion of carbon-containing fuels.

...
Wikipedia