But the improved quality of life and so on has been built up in an unsustainable manner. We have been using or otherwise destroying our non-renewable resources

But the improved quality of life and so on has been built up in an unsustainable manner. We have been using or otherwise destroying our non-renewable resources (arable land, fresh water sources, and so on) at an accelerating pace. Its actually typical for a society or civilisation to be at the height of its power before it collapses; the easter islanders had their greatest population and were constructing the biggest stone heads just before their collapse.