Terrestrial Carbon Storage

Carbon is stored in living and dead organic matter above and below the ground. Changes in terrestrial (or land-based) ecosystems—for instance, as a result of climate or land use changes—can contribute to changes in carbon storage, which in turn can affect the climate system through the release of greenhouse gases such as carbon dioxide. 
Carbon is stored in living and dead organic matter above and below the ground. Changes in terrestrial (or land-based) ecosystems—for instance, as a result of climate or land use changes—can contribute to changes in carbon storage, which in turn can affect the climate system through the release of greenhouse gases such as carbon dioxide. 

Storage of carbon across U.S. land-based ecosystems is changing

Terrestrial ecosystems store large amounts of carbon dioxide each year: for example, net annual carbon dioxide storage by forests, urban forests, croplands, and grasslands totaled 746.9 million metric tons in 2016.

Forests (not including urban forests) annually store the majority of terrestrial carbon dioxide in the United States. Croplands and grasslands are generally net carbon dioxide sources, releasing more carbon dioxide than they are storing.
Forests (not including urban forests) accounted for more than 99% of that net annual storage. With the exception of two years since 1990, croplands and grasslands have been net carbon dioxide sources, annually releasing more carbon dioxide than they are storing.

About Terrestrial Carbon Storage

The data shown in the graph were drawn from the U.S. Environmental Protection Agency (EPA) Inventory of Greenhouse Gas Emissions and Sinks, in which annual carbon dioxide storage is estimated using three complementary datasets: the U.S. Department of Agriculture (USDA) National Resources Inventory, the USDA Forest Service Forest Inventory and Analysis, and the Multi-Resolution Land Characteristics Consortium National 
Land Cover The physical characteristics of the land surface, such as crops, trees, or concrete.
Dataset. These datasets represent a combination of statistical survey approaches and satellite data. Changes to terrestrial carbon storage reflect the impacts of many factors.
Why It's Important
  • Changes affecting these ecosystems—such as alterations in climate or
    land use Activities taking place on land, such as growing food, cutting trees, or building cities. ×
    - can contribute to changes in carbon storage, which in turn can affect the climate system through the release of 
    greenhouse gases Gases that absorb heat in the atmosphere near the Earth's surface, preventing it from escaping into space. If the atmospheric concentrations of these gases rise, the average temperature of the lower atmosphere will gradually increase, a phenomenon known as the greenhouse effect. Greenhouse gases include, for example, carbon dioxide, water vapor, and methane.×
    .
  • This 
    indicatorAn observation or calculation that allows scientists, analysts, decision makers, and others to track environmental trends, understand key factors that influence the environment, and identify effects on ecosystems and society. ×
    can help decision makers understand how 
    climate changeChanges in average weather conditions that persist over multiple decades or longer. Climate change encompasses both increases and decreases in temperature, as well as shifts in precipitation, changing risk of certain types of severe weather events, and changes to other features of the [See also global change]. ×
    , land management, natural disturbances, and 
    ecosystem  All the living things in a particular area as well as components of the physical environment with which they interact, such as air, soil, water, and sunlight. ×
    dynamics affect annual terrestrial carbon storage in the United States.