We have converted huge swaths of land and ocean into human habitats where we live and grow food and harvest energy. But there's been a sea change in the past century.

With enough money and international coordination, we can push incoming asteroids out of Earth's path. We might even be able to bring back extinct animals in the lab. The problem really isn't scientific - it's cultural. We aren't yet able to coordinate ourselves as a global civilization to do something simple like bring food to a famine-stricken region. We can actually use current satellite technologies to predict where famine will strike next, but we can't get food there - usually for political reasons.

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.

In terms of fiction, there are a number of writers who are thinking about the future of the environment whose work complements mine. Kim Stanley Robinson's novel 2312 is a great example, as is Tobias Buckell's novel Arctic Rising.

To be fair, if we are having a mass extinction, we're in the early stages of it. I think it's knowing facts like that which has made me less fearful about the future. Mass extinction is a long, complicated process that we are just now beginning to understand - and likewise, we are just beginning to understand how we might prevent one.

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.

It's only been in the past two generations that we truly understood the impact our civilization has had on the natural world. To our credit as a species, we have turned this obscure scientific fact about carbon cycles into one of the most important political issues of the 21st century.