The burning of fossil fuels like coal, gas and oil releases
particles into the atmosphere. When fossil fuels are not burned
completely, they produce black carbon -- otherwise known as
soot. Soot looks like a black or brown powder and though it's
made up of tiny particles, it can have a big impact on climate.
Black carbon stays in the atmosphere for several days to weeks
and then settles out onto the ground. It can be produced from
natural causes like when lightning causes a forest fire. Most
black carbon results from human practices like slash and burn
methods for clearing land, using diesel engines, and industrial
processes that burn coal, gas and oil, and coal burning in
homes. Black carbon is produced around the world and the type of
soot produced varies by region. Black carbon adds to global
warming in two ways. First, when soot enters the atmosphere, it
absorbs sunlight and generates heat, warming the air. Second,
when soot settles on snow and ice, it makes the surface darker,
so the surface absorbs more