When Sean Youra was 26 years old and working as an engineer, he started watching documentaries about climate change. Youra, who was struggling with depression and the loss of a family member, was horrified by what he learned about melting ice and rising extreme weather. He started spending hours on YouTube, watching videos made by fringe scientists who warned that the world was teetering on the edge of societal collapse — or even near-term human extinction. Youra started telling his friends and family that he was convinced that climate change couldn’t be stopped, and humanity was doomed. In short, he...
