> Also, the model doesn't take account technological progress or mining resources from solar system etc. Technological progress is not a given or inevitability

> Also, the model doesn't take account technological progress or mining resources from solar system etc. Technological progress is not a given or inevitability. There are real physical and material constraints affecting technological development. You can't simply handwave future problems away because "future technological development." For example, it seems very likely that extraterrestrial mining operations will never be technically and economically feasible. We have to disconnect what decades of scifi have taught us about the future from reality. In sixty years of human space travel, we've made very little progress and there's not much reason to hope for much more. > one of which is that population keeps growing exponentially. Population is already collapsing, so the whole model goes to trash bin with that in mind. It's true that exponential population growth is very obviously unsustainable. Unfortunately, the population collapse is another symptom of our problems that will ultimately lead to a systems collapse and likely ecological collapse. People are animals, however much we want to deny it. When animals stop breeding, it's because something is wrong. TFR is collapsing because of poisoned social environments, not because enlightened rational humanity saw the perils of exponential growth and took action. This in turn means that increasing proportions of our economic surpluses will be dedicated to attempted containment and control of our social problems, rather than technological development. That all said, to paraphrase Adam Smith, there's a lot of ruin in a nation. Technology, mass surveillance, and huge economic surpluses have permitted and will permit unprecedented levels of social control that may stave off a systems collapse for longer than anyone expects, even if the resulting society is dystopian by our former standards. And our understanding of our ecological system is miniscule: we can see where doing tremendous amounts of damage at almost every known point (even ignoring global warming), but it's hard to say what it takes to really send us down the drain. It will probably happen slowly, then all at once.