Ecosystem Demography Model: U.S. Ecosystem Carbon Stocks and Fluxes, 1700-2100

Atmospheric and ground-based methods agree on the presence of a carbon sink in the coterminous United States (the United States minus Alaska and Hawaii), and the primary causes for the sink recently have been identified. Projecting the future behavior of the sink is necessary for projecting future net emissions. Two models, the Ecosystem Demography model and a second simpler empirically based model (Miami Land Use History), were used to estimate the spatio-temporal patterns of ecosystem carbon stocks and fluxes resulting from land-use changes and fire suppression from 1700 to 2100. The results are compared with other historical
reconstructions of ecosystem carbon fluxes and to a detailed carbon budget for the 1980s. The projections indicate that the ecosystem recovery processes that are primarily responsible for the contemporary U.S. carbon sink will slow over the next century, resulting in a significant reduction of the sink. The projected rate of decrease depends strongly on scenarios of future land use and the long-term effectiveness of fire suppression.

References:

Hurtt, G. C., P. R. Moorcroft, S. W. Pacala, and S. A. Levin. 1998. Terrestrial models and global change: challenges for the future. Global Change Biology 4(5): 581-590.

Hurtt, G. C., S. W. Pacala, P. R. Moorcroft, J. Caspersen, E. Shevliakova, R. A. Houghton, and B. Moore. 2002. Projecting the future of the U. S. Carbon sink. Proc. Nat. Acad. Sci., 99: 1389-1394.