What man may or may not do in the future will always be in flux and unpredictable. I don’t think anyone believes that civilization will not stumble forward as it has throughout history. The difference now, if one believes in science, is that we are quickly reaching a tipping point on the degradation of the planet. That degradation will lead to further stress on what we believe and understand as civil society. If sea levels rise, the oceans die from acidity, and vast farmlands waste under the heat, all bets will be off.