Vegetation and soils are widely recognized as carbon storage sinks. The global biosphere absorbs roughly 2 billion tons of carbon annually, an amount equal to roughly one third of all global carbon emissions from human activity. Significant amounts of this carbon remains stored in the roots of certain plants and in the soil. In fact, the inventory of carbon stored in the global ecosystem equals rougly 1,000 years worth of annual absorption, or 2 trillion tons of carbon.

Another important area of research in terrestrial sequestration is the development of technologies for quantifying carbon stored in a given ecosystem. Should the United States and other nations one day adopt a carbon emissions trading program, high precisions and reliability in these measuring techniques will be necessary.

Terrestrial carbon sequestration is defined as either the net removal of CO2 from the atmosphere or the prevention of CO2 net emissions from the terrestrial ecosystems into the atmosphere.

Enhancing the natural processes that remove CO2 from the atmosphere is thought to be one of the most cost-effective means of reducing atmospheric levels of CO2, and forestation and deforestation abatement efforts are already under way. R&D in this program area seeks to increase this rate while properly considering all the ecological, social, and economic implications. There are two fundamental approaches to sequestering carbon in terrestrial ecosystems: (1) protection of ecosystems that store carbon so that carbon stores can be maintained or increased; and (2) manipulation of ecosystems to increase carbon sequestration beyond current conditions.

This program area is focused on integrating measures for improving the full life-cycle carbon uptake of terrestrial ecosystems,including farmland and forests,with fossil fuel production and use. The following ecosystems offer significant opportunity for carbon sequestration:

• Forest lands. The focus includes below-ground carbon and long-term management and utilization of standing stocks,understory, ground cover,and litter.

• Agricultural lands. The focus includes crop lands, grasslands, and range lands,with emphasis on increasing long-lived soil carbon.

• Biomass croplands. As a complement to ongoing efforts related to biofuels,the focus is on long-term increases in soil carbon and value-added organic products.

• Deserts and degraded lands. Restoration of degraded lands offers significant benefits and carbon sequestration potential in both below-and above-ground systems.

• Boreal wetlands and peatlands. The focus includes management of soil carbon pools and perhaps limited conversion to forest or grassland vegetation where ecologically acceptable.

The program area is being conducted in collaboration with DOE’s Office of Science and the U.S.Forest Service of the U.S. Department of Agriculture.