We shouldn't have stupid cars that use liquid fossil fuels. Come on, how outmoded is that? We have to get to the point where this is no longer a part of our experience.

It is critical that the world captures every last bit of energy efficiency, if we are to reduce greenhouse gas emissions enough to keep below dangerous rises in temperature. I am pleased that this important new study shows how information and communication technology can play an essential role in saving energy. Now we need more and effective government policies that reward such action and penalize delayed responses.

We have to get to the point where each individual, each corporation, each community chooses low carbon, because it makes fundamental sense. It should become a no-brainer.

No architect should design buildings that import a huge amount of energy.

We're going to get to the point where we ask how the hell we put up with high carbon for so many years. You thank your lucky stars, because you are seeing this transformation in your lifetime. You are going to tell your children and your grandchildren you saw this whole thing in front of your eyes.

This is probably the most difficult task we have ever given ourselves, which is to intentionally transform the economic development model, for the first time in human history.

In a perfect world global emissions would have peaked already. In a semi-perfect world we will peak on Dec. 31, 2020. The fact is, that's going to be difficult. We know that it's going to get more and more expensive the longer we delay.