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 U.S. Environmental Protection Agency (EPA) estimates annual U.S. carbon sequestration from land-use change and forestry in 2003 at 828.0 MMTCO₂e,⁹ representing an offset of 11.9 percent of total 2003 U.S. greenhouse gas emissions (6,983.2 MMTCO₂e). In 1990, carbon sequestration attributable to land use and forestry was 1,042.1 MMTCO₂e, or 16.9 percent of total 1990 U.S. greenhouse gas emissions (6,148.8 MMTCO₂e).¹⁰ The EPA’s 2003 estimates for carbon sequestration from land-use change and forestry include 752.7 MMTCO₂e from forested land, 58.7 MMTCO₂e from urban trees, 10.1 MMTCO₂e from landfilled yard trimmings and food scraps, and 6.6 MMTCO₂e from agricultural soils (Table ES7).

Notes and Sources