Global warming and the carbon cycle

Global warming is the major subject in the field of earth system science. Global warming is thought to be caused by the greenhouse effect of the atmospheric CO 2, which has been increasing due to industrial emission since 1850. To reveal the reason of global warming, the key issue is to understand the global carbon cycle. In this paper, the mechanism of the global carbon cycle is systematically discussed and the current research is reviewed. It is observed that attention should be paid to several major subjects and particularly, at present, several problems should solved.