Each building should produce as least as much energy as it's going to need, and have more to put on the grid. They should be using all of the natural light and natural heat.

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 will move to a low-carbon world because nature will force us, or because policy will guide us. If we wait until nature forces us, the cost will be astronomical.

The fact is, when you talk to people, they know that something weird is going on, particularly people who are connected to the land or the water. They can see it. What perhaps is not so evident to them, unfortunately, is what the solution is. But whether they call it climate change or not, it doesn't matter. The point is, they can see there's something fundamentally weird going on here.

We cannot ask others to do what we have not done ourselves.

The U.S. military is investing in new storage technology because most of the weight that soldiers carry on their backs is batteries. Once that gets developed for the military, it will be expanded to civilians.

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.