Forests account for almost all of the world's land-based carbon uptake, a new report shows, helping end uncertainty about just how much carbon is being stored, and where.
The team, from the University of Alaska Fairbanks Institute of Arctic Biology and co-leader of the USGS Alaska Cooperative Fish and Wildlife Research Unit says that understanding the present and future role of forests in the sequestration and emission of carbon is essential for informed discussions on limiting greenhouse gases.
The scientists examined information on changes in carbon pools from dead wood, harvested wood products, living plants, plant litter, and soils.
They used this data to estimate changes in carbon across countries, regions and continents, representing boreal, temperate and tropical forests.
And between 1990 and 2007, say the scientists, they stored about 2.4 gigatons of carbon per year - vastly more than any other carbon sink.
Boreal forests are estimated to be responsible for 22 percent of the carbon stored in the world's forests. But, the scientists warn, a warming climate has the potential to increase fires and insect damage in the boreal forest and reduce its capacity to sequester carbon.
"Our results imply that clearly, forests play a critical role in Earth's terrestrial carbon balance, and exert considerable control over the evolution of atmospheric carbon dioxide," says A David McGuire, professor of ecology at the University of Alaska Fairbanks Institute of Arctic Biology and co-leader of the USGS Alaska Cooperative Fish and Wildlife Research Unit.