Daniel Schrag

Daniel Schrag investigates the history and mechanisms of global climate change by combining empirical geochemical measurements with models of chemical and oceanographic processes. Schrag’s investigation of changes in oceanic carbon chemistry revealed that the biosphere essentially shut down several times in the distant past, when the globe was apparently completely covered with glacial ice. He has also determined that the oceans cooled nearly to the freezing point in the most recent ice age, resolving a longstanding debate. To study the El Niño climatic oscillations over the last decades and in the geologic past, Schrag uses the isotopic composition of coral shells to assess the state of the ocean at the time they were alive. His research underscores the dependence of effective environmental policy on a comprehensive understanding of the physical, chemical, and biological processes that shape the biosphere. Schrag is a professor of geochemistry in the Department of Earth and Planetary Sciences at Harvard and director of its Center for the Environment. He taught at Princeton University from 1993-1997. His articles have appeared in such journals as Science, Paleoceanography, and Nature. Schrag received a B.S. (1988) from Yale University and a Ph.D. (1993) from the University of California, Berkeley.