Formulating energy policies related to fossil fuel use: Critical uncertainties in the global carbon cycle

摘要

The global carbon cycle is the dynamic interaction among the earth's carbon sources and sinks. Four reservoirs can be identified, including the atmosphere, terrestrial biosphere, oceans, and sediments. Atmospheric CO(sub 2) concentration is determined by characteristics of carbon fluxes among major reservoirs of the global carbon cycle. The objective of this paper is to document the knowns, and unknowns and uncertainties associated with key questions that if answered will increase the understanding of the portion of past, present, and future atmospheric CO(sub 2) attributable to fossil fuel burning. Documented atmospheric increases in CO(sub 2) levels are thought to result primarily from fossil fuel use and, perhaps, deforestation. However, the observed atmospheric CO(sub 2) increase is less than expected from current understanding of the global carbon cycle because of poorly understood interactions among the major carbon reservoirs. 87 refs.