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.

think we're still stuck in that agricultural mindset, where we imagine that we can shape the Earth. Sure, we can do that. But the Earth has the power to shape us much more powerfully. To survive climate change, we'll have to realize how dependent we are on our ecosystems for our own survival.

That said, a lot of people buy products with "green" in the brand name, but make no attempt to understand what it would really take to live sustainably. I think one of the most pernicious examples of magical environmental thinking is the anti-GMO movement.

I think that humans are also set up to survive. We're not as small as rats, but we make up for that by being intelligent enough to make our own hiding places and to adapt to new habitats, even if they are changing very quickly. We have an enormous population, and can afford to lose billions of people without suffering very much as a species. Indeed, some would say losing five billion people would be good for the planet - I disagree with them, but can't deny that we would do just fine if there were two billion of us or even one billion.

Imagining the world without us is a recipe for despair and paralysis. I actually think it's more helpful to imagine the world before us, to look back at those unstable ecosystems of the Triassic and realize that were in another phase of unstable ecosystems. Knowing that, demystifying our situation as it were, makes it easier to think about solutions. We are not looking into the unknown. The only thing unknown about the situation is how we're going to fix it, and when.

I would want us to start our quest to survive mass extinction by rethinking how we build cities. Cities should be commonplaces of production, rather than consumption - they should be producing food, and fuel.

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.