What happens to the carbon stored in forests?

"Forests store carbon as they grow, however, when they are degraded or cleared their stored carbon is released back to the atmosphere, thus these forests become net contributors of carbon to the atmosphere. It is estimated that the rapid destruction of tropical forests has been responsible for approximately 20% of total human-caused carbon dioxide emissions each year
    Forest soils and vegetation store about 40 percent of all carbon in the terrestrial biosphere, more than any other ecosystem.
    Globally, more carbon is stored in forest soils than in forest vegetation. Boreal forests are especially rich in soil carbon, while tropical forests probably store more in their vegetation.
    Regrowth of forests in developed countries may account in part for the increasing terrestrial sink that absorbs some of the carbon dioxide emissions released by fossil fuel combustion. However, land use change, primarily tropical deforestation, currently releases an estimated 1.6 billion tons of carbon to the atmosphere each year, equivalent to 25 percent of emissions from fossil fuel combustion.
    Globally, deforestation far exceeds regrowth. The world's forests are therefore currently a net source of carbon.