Modeling the geochemical carbon cycle

The authors have modeled the slow, long-term cycle in which geochemical processes transfer carbon among land, sea, and atmosphere. The model suggests that the earth may have been warmed in the past when buildups of atmospheric carbon dioxide enhanced the greenhouse effect. The model predicts that the slow natural fluctuations of atmospheric carbon dioxide may rival or even exceed the much faster changes that arise from human activities or from the biological carbon cycle. The main purpose in modeling the geochemical carbon cycle is to expose how little is known about the rates of important global processes and how seemingly unrelated processes (such as tectonism and climate) are linked.