What if our decisions, due to the culture and lifestyles of developed nations, free markets, and short-to-mid-term democratic attention spans, lead to an ecological catastrophe that can't be technologically ameliorated 100 years from now? What if it could have been mitigated at present with modest intellectual effort and modest cuts to standards of living?
I recognize many problems with the sort of governance that would be required to mitigate long-term ecological and technological problems (ecological collapse, grey goo, unfriendly AI), but calling it "Pol Pot Level" evil to trade some quality of life in the present for reduced risk of having the biosphere take a wrong turn a generation or two from now, seems polemical. If reduced quality of life increases mortality rates, that's unfortunate, but concern about people today should not trump concern about people in the future, to the extent we can foresee risks due to stressing the biosphere in ways we have no empirical analogs for.
I think the popular idea that technology can and will overcome problems we cause in our biosphere, is unsupported (and unsupportable, even if it's true) by evidence. We either take it on faith or we don't; I choose not to.