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.

My first goal would be to reduce the perturbation in the carbon cycle. That would mean using carbon neutral sources of energy, and changing our agricultural practices to be less disruptive and polluting. I'm not talking about a policy here so much as changing the way our infrastructure works. That's why I'm so fascinated with changing the way we build cities, because they are the most developed forms of physical infrastructure for human habitation.

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.

Sometimes it's hard to take everyday concerns seriously when you think about vanished ecosystems that existed 300 million years ago and were eradicated by giant explosions. My goals haven't changed, because my goal has always been to save the world!

If we return abruptly to a Miocene-like climate, it's reasonable to think that we would experience a lot of extinctions, and maybe even a mass extinction in the long term. Would the life on Earth be radically different? Of course we can't say for sure, but I think a lot of it would look familiar. Like a lot of people, I worry a lot about whether marine mammals would survive, especially whales. Ocean acidification is one of the major killers in climate change events, and that makes the ocean a very inhospitable place.

It's only a slight exaggeration to say we haven't progressed much beyond the invention of agriculture when it comes to our view of the natural world.

Obviously it depends on how you define a word like "evolution," because of course we have been evolving - both biologically and culturally - in relation to the natural world for hundreds of thousands of years.