Abstract

Anthropogenic greenhouse forcing may be enhanced by Climate – Carbon Cycle feedbacks. Examples of such feedbacks are large-scale biome alterations like rainforest to savannah conversion, or changes in the ocean anthropogenic carbon uptake pathways. Recently there have been several studies indicating that such feedbacks are already operating. This talk addresses the question what existin g data tell us about such feedbacks. The talk will first use the global atmospheric greenhouse gas record and simple models to analyze whether atmospheric carbon dioxide records support the conclusions on feedbacks of published studies. Next, data from a large-scale long-term Amazon forest functioning network will be discussed in the same light. Then implications of the first year of atmospheric CO2 3D data from a now regular greenhouse gas observation program over the Amazon basin based on aircraft will be presented and put in perspective with results from other recent studies. Finally I’ll summarize.