Sack Lunch Seminar (SLS)

From molecules to climate models: Fossil lipid insights into tropical paleoclimate


The tropics are home to the majority of Earth's water vapor – an important greenhouse gas – and rapid climate reorganization within the tropics affects climate worldwide. Understanding how tropical climate has behaved throughout Earth History is critical to improve our understanding of tropical climate dynamics. Here I demonstrate how we can use molecular biomarkers – fossil molecules preserved in sediments and in the rock record – to learn about past changes in tropical climate. This talk will focus primarily on the use of the hydrogen isotopic composition of leaf wax lipids as a proxy for the isotopes of precipitation, and I will show how we can integrate proxy-inferred isotopic changes with isotope-enabled modeling experiments to illuminate past changes in precipitation amount and atmospheric processes. I will also discuss application of the TEX86 paleothermometer – a proxy based on the relative cyclization of archaeal glycerol dialkyl glycerol tetraether membrane lipids – towards reconstructing temperature change in lacustrine environments.