Feedbacks and Interactions between Global Change, Atmospheric Chemistry, and the Biosphere.
A very thought provoking review paper from the Max Planck Institute for Chemistry (Otto Hahn Institute) Biogeochemistry Department, Germany. The research in by Professor Andreae's et al and is closely tied to the International Biosphere/Geosphere Program, and involves a high amount of international collaboration.
And check out the amazingly detailed diagram: CONCEPTUAL MODEL of Earth System process operating on timescales of decades to centuries. You may discover a lot of existing and potential feedbacks. (negative or positive...)
Here is a simplified, nicely colored overview of that diagram via NASA (1988)
Earth Systems Science: an Overview