This week’s flooding in Vermont, in which heavy rainfall caused destruction even miles from any river, is evidence of an especially dangerous climate threat: Catastrophic flooding can increasingly happen anywhere, with almost no warning.

And the United States, experts warn, is nowhere close to ready for that threat.

The idea that anywhere it can rain, it can flood, is not new. But rising temperatures make the problem worse: They allow the air to hold more moisture, leading to more intense and sudden rainfall, seemingly out of nowhere. And the implications of that shift are enormous.