Human
activity is also adding CO2 to the atmosphere
through deforestation. When tropical
forests are clear cut, the land is typically
converted to pasture. The original
forest
and its soil have a much higher carbon content
than the pastureland, so the process of
burning the forest must result in a significant
release of carbon to the atmosphere.
Deforestation
is thought to be releasing about 2.2
gigatons of carbon every year into the atmosphere.