My Children, I Have Grave News

[Cavebear]

Well, so would global thermonuclear war, but that's not necessarily a good thing...

There are over 6 billion of us.  A little less procreation might be beneficial.  It would have no direct harm to others and some benefits.  A global thermonuclear war would be rather bad for most living creatures.

Put more directly, having fewer of us by natural means would be a lot easier on the living than Nuclear Winter.  Ask the dinosaurs...