We are interested in what controls long-term and short-term climatic and environmental change from the Archean to the Holocene. Particular areas of research include glacial-interglacial climate variability; greenhouse-icehouse oscillations; abrupt climate change; long-term and short-term carbon cycling; oxygen evolution of the atmosphere; physical and chemical weathering; origin and evolution of Earth’s atmosphere; chemical oceanography; and water-rock interactions in the surface, deep-sea, and shallow crust and sediments. We use a variety of tools including stable isotope geochemistry, elemental geochemistry, biostratigraphy, sedimentology, and geophysics to reconstruct past climates in marine and terrestrial environments.