On Sun, 3 Jun 2018 22:28:56 +0200, Paul Schlyter
wrote:

It might not happen, but it cannot be excluded either. Millions of people
needlessly dying will certainly cause unrest and massive amounts of
migration on a scale we haven't seen so far. Certainly there will be wars
over this too. And it's those side effects which could be a danger to our
civilisation. Some nukes detonated, in India or Pakistan, or in the
Middle East, could be enough.

It's already happening. There are small scale resource conflicts
happening all over. The most far reaching for most of the world is the
Syrian civil war, which probably would not have occurred but for
anthropogenic drought.