During his research stay, Chiessi will focus on how climatic changes in the past have affected the Amazon rainforest and the Atlantic Meridional Overturning Circulation. While the Amazon rainforest is threatened by a dieback, the Atlantic Meridional Overturning Circulation may show a substantial slowdown or even collapse. It is important to note that the behavior of the Atlantic Meridional Overturning Circulation may influence the fate of the Amazon rainforest. The background to this is that individual components of the Earth's climate system have tipping points. A tipping point is a threshold at which a small disturbance will push the component into a qualitatively different mode of operation. If so, this can affect individual ecosystems and the entire climate system within a few centuries or less.
During his research stay at MARUM, Chiessi and his colleagues will investigate the interaction of these two components during the transition from the penultimate glacial period to the last interglacial period. This interval was marked by a marked decrease in the strength of the Atlantic Meridional Overturning Circulation. For this matter, marine sediment cores are being investigated. They were collected off northeastern South America and archived the climatic and oceanographic development of both the Amazon rainforest and the western equatorial Atlantic.
Chiessi already knows Bremen well from his time as a doctoral student. After studying geology at the University of São Paulo (Brazil), he completed his doctorate at the University of Bremen. He currently heads a research group on Palaeoceanography and Palaeoclimatology at the University of São Paulo. In 2012/13 Chiessi was a fellow at the Hanse Institute for Advanced Study in Delmenhorst.