We study past climate and biogeochemical cycles to understand how the earth system worked in the past, and how it might change in the future.  Current projects investigate past variations in greenhouse gases, chronology of ice cores and glacier variations, and extraterrestrial dust.  We conduct field work in polar regions and do lots of laboratory geochemistry.  If you are a prospective graduate student or postdoc, or an undergraduate looking for a research project, feel free to contact me.