Some time ago we discovered the carbon cycle - a long-term set of chemical reactions that govern climates based on how much carbon is free in the atmosphere. At that point, it became clear that humans were affecting our environments far more profoundly than we realized. By releasing so much carbon and greenhouse gas into the environment, we're making long-term changes to every aspect of the natural world.

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.

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.

Even though I now know that it's likely the Earth will suffer through mega-volcanoes or meteor strikes that could take out millions or billions of people, I feel less anxious about it because I actually understand what the threats are. There's nothing like researching something exhaustively to make it less terrifying.

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.

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.

Some time ago we discovered the carbon cycle - a long-term set of chemical reactions that govern climates based on how much carbon is free in the atmosphere. At that point, it became clear that humans were affecting our environments far more profoundly than we realized. By releasing so much carbon and greenhouse gas into the environment, we're making long-term changes to every aspect of the natural world.