My interest in the history of science began when I was a child and had recurring dreams of nuclear war. A long time later, I wrote a dissertation on the subject of “nuclear winter” and the politics of anthropogenic climate change. Yet the climate crisis is very different than a nuclear explosion—its impacts are distributed unequally and over a long duration. It can be difficult to teach about the climate crisis without either lapsing into catastrophism or downplaying the gravity of our situation. The problem is so complex and the means to understand its future impacts—computational models—are full of assumptions with incredible unknowns built in. That is why I believe collaborative projects that open up to engagement with the world beyond the university are essential for tackling this problem. My classes ask for a willingness to embrace radical uncertainty while still believing that some things are certain. We always have the power to redefine history and make something new—if we can remove global climate disruption from the realm of an inescapable catastrophe, we can help to galvanize people to confront the dangers they face in their communities here, now, today.