Freeman Dyson's recent essay in the New York Review was the most helpful single piece on climate change I've read in weeks. He's not as dogmatic as some climate worriers and persuasive, I'd say, in arguing that only technology can solve this problem (and government may not help much). But the possibility of genetically-modified carbon-eating trees is what really struck home:

Carbon-eating trees could convert most of the carbon that they absorb from the atmosphere into some chemically stable form and bury it underground. Or they could convert the carbon into liquid fuels and other useful chemicals. Biotechnology is enormously powerful, capable of burying or transforming any molecule of carbon dioxide that comes into its grasp. Keeling's wiggles prove that a big fraction of the carbon dioxide in the atmosphere comes within the grasp of biotechnology every decade. If one quarter of the world's forests were replanted with carbon-eating varieties of the same species, the forests would be preserved as ecological resources and as habitats for wildlife, and the carbon dioxide in the atmosphere would be reduced by half in about fifty years.

Climate change is, at its root, a scientifically-diagnosed problem that will be solved by science, not politics. Yes, politics can nudge the process along. But it's not a politically-resolvable question. Which is why it's still possible to be optimistic.