We don't know exactly where all the tipping points are in the physical world for inescapable damage, but we're clearly reaching close to some of them.

A third of summer sea ice in the Arctic is gone, the oceans are 30 percent more acidic, and since warm air holds more water vapor than cold, the atmosphere over the oceans is a shocking five percent wetter, loading the dice for devastating floods.

To me the analogy [to climate change] is... doctors worry a lot about cholesterol. And if you go to the doctor, and the doctor says "oh, your life would be happier if you ate a different diet and exercised" people pay no attention.

We have to get our states to adopt what are called "renewable portfolio standards" pledging to use a lot of renewable energy by 2015 or 2020. We have to work with businesses and shops to get them engaged in the same way.

Speaking for me, I think the odds of bankrupting Exxon are pretty small, but I think the odds of politically bankrupting them are higher. I think if we can use this as a vehicle to get out the analysis that these guys have 3-5 times as much carbon in the ground as the most conservative government thinks would be safe to burn, then that politically stigmatises them, makes them into the rogue industry that they are.

The Old Testament contains in many places, but especially in the book of Job, one of the most far-reaching defenses ever written of wilderness, of nature free from the hand of man. The argument gets at the heart of what the loss of nature will mean to us....God seems to be insisting that we are not the center of the universe, that he is quite happy if it rains where there are no people - that God is quite happy with places where there are no people, a radical departure from our most ingrained notions.

With each month that passes, a solar panel gets 2 or 3 percent cheaper. So while we're holding the fossil fuel industry in check, the engineers in the renewable energy world are undercutting them from the other side.