ah but we would not exist as these theoretically individual, competitive, differentiated beings (with sentience no less, not that that's so unique to us) if we were not at the same time symbiotic colonies of organisms.  this gets us back to an unexplored topic, the great divide between the symbiologists and the crude Darwinians (and that debate was heavily coloured and weighted by its taking place during the glory days of kleptocracy and the bootstrap of industrialism).

the cultures that have lived longest have managed to conceptualise their life as a symbiosis with their biotic infrastructure, not a cancerous infinite-growth paradigm or some (related) fantasy of somehow transcending biotic reality, being "above" it or dominating it utterly.  we're sitting around talking about "inevitable doom" as if it were normal for human beings to create a culture that burns out in 250 years or less, when we have excellent records of cultures that persisted for 10,000 years or more.  hell, even Rome took longer to fall than the US has existed as a nation-state.

as Wendell asked, "What Are People For?" -- we need to start answering that question better than we have so far.  I don't buy the inevitability argument any more than I buy Marxian notions of the ineluctable workings of History :-)

The difference between theory and practise in practise ...