Imagine a giant asteroid on a direct collision course with Earth. That is the equivalent of what we face now [with climate change], yet we dither.

Hansen frames climate change as an imminent, civilization-scale emergency by likening it to an asteroid impact—an event that would trigger immediate, coordinated action. The comparison highlights a perceived mismatch between the magnitude of the threat and the slowness of political and societal response (“we dither”). Implicitly, the quote argues that climate risk is not a distant or abstract environmental issue but a concrete danger requiring rapid mitigation. It also critiques decision-making systems that treat gradual, probabilistic harms as less urgent than sudden catastrophes, even when the ultimate consequences could be comparable.