Columbia University’s Lamont-Doherty Earth Observatory is home to the world’s largest collection of deep-sea sediment cores. These cores—and the microfossils contained in them—allow scientists to look back on thousands of years of climate conditions from all over the world. In this short film, Peter deMenocal, the chair of Columbia’s Department of Earth and Environmental Sciences, describes new techniques for retrieving sediment cores from the depths of the ocean and how they help us understand global climate change.