This summer, torrential rains have washed away Texas neighborhoods, dangerous heat has blanketed swaths of the country, and smoke from Canadian wildfires has choked communities as far south as Florida. Research makes clear that global warming is making extreme weather events more frequent and severe. Yet the climate crisis has largely disappeared from the political agenda, with many Democrats who once described it as an existential threat now shying away from talking about it. Now US activists are pushing back against this trend of “climate hushing”, arguing it is misguided. During the summer’s federal recess, during which lawmakers leave the...