Climate change may be the hardest problem the human race has ever confronted. In a single century, humans have set in motion events that will unfold on a geological timescale, ultimately redrawing coastlines around the globe as ice sheets melt and sea level rises. Can humanity agree to meet its energy needs with renewables such as wind and solar power? Is there a threshold beyond which the effects of greenhouse gases will become irreversible? Can solar geoengineering help stop this runaway train?  In this episode, Daniel Schrag, director of the Harvard University Center for the Environment and Sturgis Hooper professor of geology and professor of environmental science and engineering, and David Keith, the Gordon McKay professor of applied physics in the School of Engineering and Applied Sciences, and professor of public policy at the Harvard Kennedy School discuss the ramifications of climate change and an engineered response.

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For a transcript of this episode, go to https://harvardmagazine.com/podcast/2020/daniel-schrag-and-david-keith

Ask a Harvard Professor is hosted by Jonathan Shaw, Marina Bolotnikova, Jacob Sweet, and produced by Jacob Sweet and Niko Yaitanes. Our theme music was composed by Louis Weeks.