In many respects, Kenneth Boulding The Economics of the Coming Spaceship Earth is the seminal article in describing this 'closed' system and interpreting the world economy or econosphere as a number of inputs and outputs, most significant being material, energy, and information... "From a material point of view, we see objects passing from the non-economic into the economic set in the process of production, and we similarly see products passing out of the economic set as their value becomes zero." As for the energy system, Boulding notes there is no escape from the 'grim Second Law of Thermodynamics'. The large energy inputs which we have obtained from fossil fuels can only be temporary.
The presence of "slack" in a culture 'permits a divergence from established patterns and activity' not merely devoted to reproducing the existing society but to changing it. Boulding's key point is that the closed earth of the future requires economic principles which are somewhat different from those of the open earth of the past. The open economy is like a 'cowboy economy,' the cowboy being "symbolic of the illimitable plains and also associated with reckless, exploitative, romantic, and violent behavior, which is characteristic of open societies." The closed economy of the future could be seen as a 'spaceman' economy, in which the earth has become a "single spaceship, without unlimited reservoirs of anything, either for extraction or for pollution, and in which, therefore, man must find his place in a cyclical ecological system which is capable of continuous reproduction of material form even though it cannot escape having inputs of energy."
So, one planet, many peoples. Here in Aotearoa/NZ we still struggle with two peoples, one Treaty. Bon chance.