Organic biogeochemistry and past global change.

Organic biogeochemistry is regarded more and more as an important method in the study of past global change. In paleoceanography, it plays an important role in determining the temperature of the paleo-sea surface, providing an understanding of the relationship between the primary paleoproduction and the carbon cycle, and testing the hypothesis of submarine methane release. It also contributes to the terrestrial paleoecological and paleoenvironmental issues, such as vegetational evolution, changes in C3 to C4 plants and paleolimnologic variations. This article gives a general review on the status of knowledge on these aspects.