The lack of knowledge of the possible modes of interaction between natural climate variability and anthropic effects on the climate system may have tragic consequences to society. One of the restrictive factors for an appropriate discussion of this issue is the temporal limitation of the instrumental climate records. These records are simply not long enough to support robust multidecadal, centennial and longer investigations. Thus, a proper knowledge of the natural climate variability is essential to evaluate the anthropic impact on the climate system and related ecosystems while also contributing to the production of reliable future climate change scenarios. Past climate records reconstructed based on geochemical analyses from stalagmites and marine sediments may significantly contribute to our understanding of climate change.
Notwithstanding some recent studies our knowledge of the paleoclimatic variability of (sub)tropical South American and South Atlantic is very fragmented. Within this subproject we expect to significantly contribute to the debate of the potential impacts that past climate change had over (sub)tropical South America.
In this regard, the main objective of this subproject is to (i) determine the variability of precipitation over (sub)tropical South America in millennial to multidecadal time scales, and (ii) attribute primary causes for the reconstructed changes. This study will be based on isotopic, geochemical and sedimentological analyses from stalagmites and marine sedimentary cores collected in carefully selected sites from South America and the South Atlantic. This study is of key importance to disentangle the natural and anthropogenic climate forcing over (sub) tropical South America. The paleoclimatic records produced herewith will also serve to validate outputs from climate models.