Land-Use Change and Forestry 

Forest lands in the United States are net absorbers of carbon dioxide from the atmosphere, primarily as a result of the reversal of the extensive deforestation that occurred in the United States during the late 19th and early 20th centuries. Since then, millions of acres of formerly cultivated land have been abandoned and have returned to forest, with the regrowth of forests sequestering carbon on a large scale. The process is steadily diminishing, however, because the rate at which forests absorb carbon slows as the trees mature, and because the rate of reforestation has slowed. 

The EPA estimates annual U.S. carbon sequestration from land-use change and forestry in 2004 at 780.1 MMTCO₂e,⁶ representing an offset of 11 percent of total 2004 U.S. greenhouse gas emissions (7,104.6 MMTCO₂e). In 1990, carbon sequestration attributable to land use and forestry was 910.4 MMTCO₂e, or 15 percent of total 1990 U.S. greenhouse gas emissions (6,112.8 MMTCO₂e).⁷ The EPA’s 2004 estimates for carbon sequestration from land-use change and forestry include 637.2 MMTCO₂e from forested land, 88.0 MMTCO₂e from urban trees, 9.3 MMTCO₂e from landfilled yard trimmings and food scraps, and 45.6 MMTCO₂e from all other sources, including net emissions of 7.3 MMTCO₂e from grassland soil stocks (Table ES7).

Notes