One of the reasons I think the population question is important, if we want to be as green as possible, any of our energy that is truly renewable is limited. Solar and wind are intermittent and they're so diffuse, it's difficult to harness them in a significant way. But one thing we could be doing is making it a law (like it is in Israel and Cyprus) to take every building eight stories or under and heat all of the water in those buildings with solar energy. It's absolutely simple and cheap technology.

One of the reasons I think the population question is important, if we want to be as green as possible, any of our energy that is truly renewable is limited. Solar and wind are intermittent and they're so diffuse, it's difficult to harness them in a significant way. But one thing we could be doing is making it a law (like it is in Israel and Cyprus) to take every building eight stories or under and heat all of the water in those buildings with solar energy. It's absolutely simple and cheap technology.

All of us humans have myriad other species to thank. Without them, we couldn't exist. It's that simple, and we can't afford to ignore them, anymore than I can afford to neglect my precious wife--nor the sweet mother Earth that births and holds us all. Without us, Earth will abide and endure; without her, however, we could not even be.

The fact that the infrastructure is falling apart is not necessarily because it's built poorly. The New York City subways were built in 1903. The fact that they're still running at all is an enormous success. The fact that New York City's bridges have held up as long as they have is extraordinary, and the engineers didn't have computers to tell them about tolerance. They overbuilt these things - traffic on them is like an ant on an elephant.

Without us, Earth will abide and endure; without her, however, we could not even be.

Most people would rather not hear about the environment because it's scary, so my goal was to write something that was readable so that people would learn a lot and not be so depressed that they would throw the book away.

The real people who hold our civilization together are the maintenance people. If it weren't for them - pumping water out of subways, painting bridges to keep from rusting, fixing a steam pipe that is 70 years old - we'd be sunk. If we got rid of all the politicians and the policymakers in the world, the world would keep going. If you get rid of maintenance people, the whole thing breaks down.