At http://math.ucr.edu/home/baez/balsillie/ John Baez has slides from his recent talks on the characterization of climate change and what we will do about it. They are clearly thought out and presented, as always. Climate change is just one aspect of the anthropocene: the new era created by human activity. One of the todo actions is to leave fossil fuels in the ground.
The elephant in the room of this story is that our best chance to leave fossil fuels in the ground is to find cheaper energy and the only realistic chance of that lies in developing nuclear power. The trouble is that the anthropocene has arisen from cheap energy. It lets us destroy habitats, destroy fish stocks, and much more. Cheaper energy will make this worse, even if it fixes the CO2 problem. The answer will lie in extending the 19th/20th century idea of a national park, to create an international park which is a substantial subset of the biosphere. The other side of the coin is the human conquest of space. There are many lifeless worlds out there, just waiting for us to make them more interesting.