Cities should function more like ecosystems, or even metabolisms. When we build, we should be thinking about how we can integrate into the ecosystems around us, but without sacrificing all the niceties of civilization like good restaurants, concert halls, and high-speed Internet access. I'm saying that partly tongue-in-cheek, but I'm also deadly serious. The future of technology is sustainable ecology.

So science alone cannot solve this problem [mass extinction of humans]. It's something that we can only tackle by bringing science together with culture, economics, and even politics.

One reason that we're so adaptable is that humans are excellent tool users and homebuilders. When our environment doesn't provide us with something that we need, we try to make it ourselves out of whatever is available, whether that's rock or wood or ore or DNA.

Part of what I wanted to do in my book was point out that we have almost reached the point where we can prevent a mass extinction with the science and technology we have today. We can build carbon neutral cities.

We are headed to a radically new Earth, at least from our perspective. But from the planet's perspective, this is nothing new. As the geologist Peter Ward is fond of pointing out, we are actually heading back to a time kind of like the Miocene. The Miocene ended about 5.5 million years ago, and it was the last time that the planet had no icecaps.

Using virtual world, a scientist in Japan can conduct an experiment using a special facility in California, watching the entire thing via a live stream - and possibly controlling the experimental equipment remotely. We can use that same kind of technology to control a robot on Mars.

There are definitely recurring themes in humanity's relationship with our environment. The biggest is probably adaptation, because humans are incredibly good at adapting to new environments in relatively short periods of time. The ancestors of Homo sapiens started leaving Africa over one million years ago, moving from warm, tropical climates into the freezing wilderness of Europe and the desert ecosystems of the Middle East.