Molecular perspectiveson Pliocene subtropical hydroclimate

Geologic evidence suggests drastic reorganizations of subtropical terrestrial hydroclimate during past warm intervals, including the mid-Piacenzian Warm Period (MP, 3.3 to 3.0 Ma). These changes, which involved mesic conditions on subtropical continents, are at first glance at odds with theory that predicts subtropical drying in a warmer world. The mechanisms and precise patterns of regional hydroclimate during the MP remain unclear. In this talk, I show that compound specific isotopic analyses of lipid biomarkers can be used to constrain the drivers of Pliocene subtropical hydroclimate, with special focus
on ongoing in western North America and other Mediterranean regions. Our results show that regional SST patterns play a key role in determining Pliocene subtropical hydroclimate. Moreover, we are able to identify similarities between Pliocene hydroclimate and current patterns of hydroclimate variability and change in subtropical regions, suggesting that the Pliocene can serve as an analog for understanding hydroclimate responses to anthropogenic warming.