I think the only thing that can save us short-term is technology. Inventing and implementing new gizmos is something we're actually good at. Long-term we're probably screwed anyway, because we'll eventually disturb the biological systems on the Earth too much (either via pollution, ocean acidification, killing biodiversity, soil depletion etc.), and they're way too immense and complex for us to fix. People forget that we're part of Earth's ecosystem, but if we disturb it too much we'll be reminded of it either via plagues (we got a taste of it already) and/or famines.