Consistent Land- and Atmosphere-Based U.S. Carbon Sink Estimates

• DOI: 10.1126/science.1057320
• Publication Date: 2002-07-27T09:53:24Z
• Authors: S. W. Pacala; G. C. Hurtt; D. Baker; P. Peylin; R. A. Houghton; R. A. Birdsey; L. Heath; E. T. Sundquist; R. F. Stallard; P. Ciais; P. Moorcroft; J. P. Caspersen; E. Shevliakova; B. Moore; G. Kohlmaier; E. Holland; M. Gloor; M. E. Harmon; S.-M. Fan; J. L. Sarmiento; C. L. Goodale; D. Schimel; C. B. Field
• Keywords: Carbon sink; Sink (geography); Carbon flux; TRACER; Carbon fibers

For the period 1980-89, we estimate a carbon sink in coterminous United States between 0.30 and 0.58 petagrams of per year (petagrams = 10(15) grams carbon). The net flux from atmosphere to land was higher, 0.37 0.71 year, because 0.07 0.13 exported by rivers commerce returned elsewhere. These land-based estimates are larger than those previous studies (0.08 0.35 year) inclusion additional processes revised some component fluxes. Although uncertain, about one-half total is outside forest sector. We also estimated using atmospheric models concentration dioxide (the tracer-transport inversion method). range results atmosphere-based inversions contains estimates. Atmosphere- thus consistent, within large ranges uncertainty for both methods. Atmosphere-based 1980-89 similar 1985-89 1990-94, indicating relatively stable U.S. throughout period.