Grand theory

What are the key patterns that maintained us and increased our numbers?
Humans are, on net balance, builders rather than destroyers. The evidence is that the civilization which our ancestors have bequeathed to us contains more created works than the civilization they were bequeathed.

If one notices only the using-up and destructive activities of humankind, without understanding that constructive patterns of behavior must have been the dominant part of our individual-cum-social nature in order for us to have survived to this point, then it is not surprising that one would arrive at the conclusion that resources will grow scarcer in the future.

High fertility leads to increased chances of survival of the group. High fertility leads to resource problems which then lead to solutions to the problems which usually leave humanity better off in the long run than if the problems had never risen.

The concept of the second law of thermodynamics underlies a vision of the human condition as inexorably sliding toward the worse in the long run. The concept of entropy is unquestionably valid and relevant for a closed container in the lab. It may also be relevant for any larger entity that can reasonably be considered a closed system. But the earth is not a closed system because both energy (from sun) and matter (cosmic dirt, asteroids, debris from many planets) constantly rain down on the earth. With respect to energy there is no practical boundary surrounding any unit of interest to us, and without such a boundary, the notion of entropy in the large is entirely irrelevant to us.