This is a brief description of studies that exemplify the methods and approaches that have been developed and used by Oak Ridge National Laboratory (ORNL) researchers in conducting integrated assessments. See the complete list of Integrated Assessment Briefs to find out more about ORNL's efforts in integrated assessment. Contact Mike Farrell ( for more information.

The Global Carbon Cycle

Research on the global carbon cycle has met more complexity than expected.

How much progress has been made in understanding the global carbon cycle over the past 15 years?

The most important recent developments are (1) information on the contribution of land clearing to atmospheric CO2 levels, (2) long-term records of atmospheric CO2 concentrations obtained from ice cores, and (3) much-improved estimates of how much carbon is stored in and exchanged among oceanic, atmospheric, and terrestrial reservoirs.

Research has uncovered more complexity than was previously appreciated. Researchers are unable to balance all the fluxes of the global carbon cycle over the period 1800 to the present, and different mathematical models give results that are difficult to reconcile.

A new global systems approach shows promise in solving current difficulties.

Post, W. M., T.H. Peng, W. R. Emanuel, A. W. King, V. H. Dale, and D. L. DeAngelis. 1990. The global carbon cycle. American Scientist 78:310-26.

Where To?

[ Next Brief | Section 2 | Table of Contents for ORNL Integrated Assessment Briefs ]

Integrated Assessment Briefs. 1995. ORNL/M-4227. Oak Ridge National Laboratory, Oak Ridge, TN.