Fig. 7.

ENSO and carbon cycle feedbacks on climate involving the Amazon rain forest. (A) Relationship between the Equatorial Pacific zonal SST gradient and Amazon rainfall for winter as observed (asterisks) and simulated by the Hadley Centre model (diamonds), which includes climate feedbacks on the carbon cycle. Linear relations are indicated for the model (present and future) and observations. In the model, the SST gradient weakens in the future, leading to reduced Amazonian rainfall and rainforest dieback. (B) Global land carbon uptake is sensitive to climate change. When climate feedbacks on the carbon cycle are included (solid) land becomes a source of atmospheric carbon around 2050; Amazon rainforest dieback is a major contributor. When they are not included (dashed) land always remains carbon sink. [Reproduced with permission from ref. 37 (Copyright 2004, Springer).]