Climate change can feel like an impossible crisis these days. Every week there is some new report about the irreversible damage we’re doing to our planet and the havoc it will bring to people’s lives. We all know cutting emissions is the solution, yet governments and companies seem no closer to meeting the goals that scientists say we must hit. It can feel hopeless.There is one possible controversial solution to climate change many in the mainstream haven’t discussed. It’s so controversial, in fact, that some experts say we shouldn’t even be discussing it. But University of Chicago Professor David Keith says we need to talk about it. It’s called solar geoengineering—the process in which you reflect a small fraction of sunlight back into space. As the founding director of the Climate Systems Engineering Initiative at UChicago, Keith is leading a team that will research solar geoengineering and other novel solutions to climate change.