he result would be to reduce our species to a mode of existence that even the heartiest "outdoorsman" wouldn't choose, assuming he was able to withstand it.

That's utterly hyperbolic bullshit. We already have alternative fuel sources, electric cars exist now and were even built decades ago. We have renewable energy and could drastically lessen our dependence on fossil fuels. The reason we are not is because it is expensive to convert infrastructure over so corporations don't want to spend the money on it.

Banning fossil fuels does not take us back to the stone age, it forces us to switch over to newer technologies that we already have sooner.

Fossil fuels were definitely a great boon for humanity, but that does not mean it comes without cost. Nor does it mean we can't do better.