My research, called “molecular paleoclimatology,” focuses on studying past climate change and investigating the paleoenvironmental information encoded fossil molecules (called ``biomarkers”) preserved in sediments. Why study past climate change (paleoclimate)? Just as history informs us about human behavior, paleoclimate informs us about the nature of climate change on Earth. In doing so, it also helps the climate community predict the effects of anthropogenic global warming. I use organic geochemistry, stable isotopic analysis, climate model output, and statistical approaches to piece together the history of Earth’s climate. Biomarkers produced by plants and microbes are particularly useful tools because environmental conditions like temperature and aridity are encoded in their molecular structure. We can calibrate these relationships using modern-day samples, and then apply these biomarker “proxies” to reconstruct climate deep into the Earth’s geologic past.