Abstract
Land-use change and forestry is the major category featuring carbon sequestration in the annual US Greenhouse Gas Inventory, required by the United Nations Framework Convention on Climate Change. We describe the National Greenhouse Gas Inventory and present the sources of our data and methods and the most recent results. Forests and forest products in the United States sequestered more than −790 million metric tn of CO2 equivalent in 2008, on 253 million ha of forestland. This estimate represents a net increase in carbon, including effects of growth, harvests, or other disturbances of forest ecosystems, as well as carbon stored in harvested wood products. Both area and carbon density of these forestlands have increased since 1990, the first year estimates are required. Currently, 89% of net annual sequestration is in the forest ecosystem, and the balance is net carbon addition to harvested wood products.