I am a professor and researcher specializing in paleoclimatology, historical climate change, and global carbon cycle research. My work involves understanding the Earth’s climate system by developing environmental data sets to evaluate climate models and ultimately to improve climate prediction. I focus largely on past ice age climates and the carbon cycle. I use data from the geological record to test model simulations of past climates, and also to deduce which processes are dominant contributors to ice age climates. I collaborate broadly and internationally with both observationalists and modelers, and have published more than 40 papers in high-impact journals that have received >3000 citations.