Professor Jacobson and his students specialize in low-temperature aqueous and radiogenic isotope geochemistry. They combine fieldwork, laboratory experiments, and modeling to quantify chemical, physical, and biological phenomena that cycle elements and their isotopes at the Earth’s surface. Several investigations focus on mineral weathering and precipitation reactions that cycle carbon and other elements, link inorganic and organic aspects of the Earth system, and control the geochemistry of soils, rivers, aquifers, seawater, and the atmosphere. Related efforts seek to understand the causes and consequences of climate change.