Daniel Schrag is the Sturgis Hooper Professor of Geology and Professor of Environmental Science and Engineering, as well as the Director of Harvard University Center for the Environment. He studies climate and climate change over the broadest range of Earth history. He has examined changes in ocean circulation over the last several decades, with particular attention to El Niño and the tropical Pacific. He has worked on theories for Pleistocene ice-age cycles including a better determination of ocean temperatures during the Last Glacial Maximum, 20,000 years ago.
Dan also helped develop the Snowball Earth hypothesis, proposing that a series of global glaciations occurred between 750 and 580 million years ago that may have led to the evolution of multicellular animals. Currently he is working with economists and engineers on technological approaches to mitigating future climate change.