We are not going to have sustainable economics unless population is under control. We cannot have sustainable economics if everyone is free to make up their own mind whether they care about efficiency and sustainability. We might as well not have numbers, when people mix measure of money and energy, and make decisions on whims of what they consider important at the moment. There is a very simple linkage here. Resources start off abundant, therefore the market says they are cheap.
People are wasteful of cheap resources, because they are cheap.
They have lots of babies on the fact that resources are cheap. And then the resources are used up, you have all these people, things crash. It gets more complicated because people learn to substitute resources, but this just puts off the day of reckoning. I say that people are interdependent, we are inherently communist. But the Marxist economies used money, and they had central planners decide what prices would be.