Book Review: Dimming the Sun: The Urgent Case for Geoengineering by Thomas Ramge

This review was first published by Booklist on March 1, 2025.

Solar geoengineering—altering the albedo of Earth to reflect more of the sun’s energy and cool down global warming—is an idea that has long floated around the periphery of climate-change-action circles. Ramge argues that it’s an idea whose time has come. It has the potential to make a significant, immediate impact and is easily reversible. It could be accomplished on a large scale with technology that’s commonplace right now. But Ramge also urges caution: it’s not a long-term solution, merely a step that can buy us time to meet necessary carbon-reduction goals. He sees a realistic danger that nonstate actors may take it upon themselves to pursue this path. There’s been very little research into solar geoengineering, so we don’t have a full understanding of the risks and possible consequences. The possibility that someone, somewhere, may turn to this approach creates an urgent need for better understanding and regulatory framework. Dimming the sun is a realistic and potentially powerful option to combat climate change. Ramge believes we should at least explore the possibility.