It is becoming more and more obvious that maybe the majority of humanity doesn't need saving. In truth, the types of changes we can expect from our upsetting of the natural climate regulatory systems are going to strike much closer to home than people think. For instance, crop yields will be hit with the both less usable ground water and inhospitable conditions for growth (not to mention many major staple crops are highly petroleum dependent). That is just the tip of the ice burg.
The raw facts of it, there is no way to support earth's current population in a sustainable way. Let alone those who blindly cling to their high standard of living as though it was a fundamental right. Worse yet, chances are we have already past the point of no return on our environmental damage. I say we let those who refuse to give up their comfy deck chairs sink with the Titanic. "Saving the World" is no longer an option. Quite frankly, I wouldn't want to save much of humanity as it is currently anyway.
The ones closest to the best path are being told by the rest of us that they are wrong. Indigenous Californians practiced sustainable fishing long before they knew the Spanish existed. They practiced better stewardship than we can even think of legislating today. Other less universalizing inclined cultures share similar traits of long term successful co-existence with the ecosystems they have learned to cherish and rely on. Our "mastery" of nature is nothing more than a fleeting victory in the co-evolutionary arms race that characterizes so many bio-systems on our planet.
Mother nature always bats last, and always bats 1000.