People are not locusts. But we are products of nature, and, as we know, nature is red in tooth and claw. When the resources in one place runs out, people will migrate, en masse for safety, to invade other places where resources to survive can be found. This is because the number one rule for each individual is survival. It is not respecting your comfort (sorry). We can avoid this eventuation. We can avoid it with armies, or we can avoid it with smart policy to restore global ecosystems before it occurs. It is the number one task of governments to preserve the security of its constituents. To governments in comfortable countries, it would be good policy for your constituents for you to make polices to allow the global ecosystems to restore balance, now. It will be too late to do it later. Right now in history, it is the job of governments to do whatever it takes restore balance to the natural world, above all else.