What are the solutions to slowing the harmful effects of climate change? Could a plausible one be to block some sun to cool the planet? It may sound far-fetched but scientists are studying solar radiation management as one potential tool in the toolbox. But–it’s a controversial one. Could it be our emergency escape hatch, or a devastating Pandora’s Box? Two environmental pioneers discuss dimming the sun and other tactics to manage climate risk. Energy and Climate Editor for The Economist Vijay Vaitheeswaran speaks with Fred Krupp, president of Environmental Defense Fund, and David Keith, director of the Climate Systems Engineering Initiative at the University of Chicago.