In a recent paper published in Reviews of Geophysics, UMass Distinguished Professor Raymond Bradley synthesized information from lake sediments, stalagmites, and offshore marine sediments to provide a comprehensive record of changes over the past ?70,000 years. He and coauthor Henry Diaz describe how freshening of the subpolar North Atlantic led to a rapid reduction in the northward flux of heat by the ocean, subsequent reorganization of the atmospheric circulation, and, in turn, climate modifications in various parts of the world. Read the paper here.