The 30th Annual Victor Starr Lecture Presented by the Program in Atmospheres, Oceans and Climate MIT’s Dept. of Earth, Atmospheric and Planetary Sciences (EAPS) Science in the Age of Models: Is Theory Still Relevant in Climate Research? Geoff Vallis (Senior Scientist and Professor GFDL and Princeton University) Numerous aspects of climate research are becoming dominated by models, in particular, by large General Circulation Models (GCM’s), and theory in the traditional sense seems to be playing a smaller role. What should that role be, if any? Are theories now subsidiary to models? Do we need a theory of climate, and what would that be? Perhaps GCM’s, as the embodiment of our collective understanding, are that theory? I’ll try to connect these seemingly abstract questions with concrete and topical issues in the climate sciences, such as ocean mixing, large-scale atmospheric circulation, global warming, and understanding paleo-climate regimes. All are welcome.