Re: Nuclear winter?

Pure speculation, not least since (as already noted) various natural processes release far more energy and the Earth has been getting large lumps of rock thrown at it for millions of years without serious consequences.

When Alvarez wanted to turn the idea of nuclear winter into a serious theory of mass extinction, he had to posit a lump of rock that would release *far* more energy than the world's nuclear arsenals.

And even that (or mass volcanism, or whatever) didn't leave just cockroaches.