Hear, hear.

You're going a bit far here, reducing the population to 1% of 1% of today's population.

Humans individually are good survivors - better than roaches.

Most of the world will become a lot less nice to live in, and some parts will literally be scoured of life, but some significant fraction of humans will still survive, though at a much lower level of technology. Whether that fraction is 10% or 1% or even lower than that depends on how far we go before we collapse out.

But this is deckchairs on the Armageddon. It will be bad.