Kim Cobb's research has taken her on several oceanographic voyages around the tropical Pacific and on caving expeditions of the rainforests of Borneo. Cobb's research group uses corals and cave stalagmites as archives of past climate change, investigating past climate variability over the past several thousand years. In addition to generating high-resolution paleoclimate records, Cobb's research group also monitors modern climate variability, performs model analysis, and characterizes tropical Pacific climate variability. She and her team collected ancient coral fragments from the islands of Kiribati and Palmyra, aged them with uranium–thorium dating and then used the oxygen isotope ratio cycle to measure the intensity of El Niño events over the past 7,000 years.