To the Editor:

Christopher Caldwell, in his condescending assault on Greta Thunberg , the 16-year-old Swedish high school climate activist (Op-Ed, Aug. 3), asserts that “democracy often calls for waiting and seeing.” For what exactly does he propose that we wait and see?

Evidence of “global heating” — an appropriate successor to the more tepid “global warming” — is unequivocal, and Ms. Thunberg is masterful in marshaling the relevant data. She is a deeply principled, well-informed critic of complacency.

Contrary to Mr. Caldwell’s assertion, it is not hard to imagine what “a real, non-utopian low-carbon politics” would look like. In the United States and abroad, we abound in policies that are beginning to reshape the energy profiles of our buildings, transportation systems, electricity sector and consumer habits. Significantly ramping up those policies is a civic imperative, not a threat to democracy.

We should all thank Ms. Thunberg for her courage and forthrightness, not deride her for her youthful determination.