There is no going back, our entire way of living is unsustainable, climate change is going to happen. Good news is, planet Earth will be fine, give it a few thousand years, it has survived far worse.
That's not too long of a time, but maybe enough to solve these problems in any number of available ways, from biotechnology through cybernetics, nanotechnology, new advanced energy sources (some of which are being developed right now), even perhaps space travel or mega structures.