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.

Amphibians are dying out like crazy, and frogs and salamanders may be largely extinct by the end of the twenty-first century. Imagine an animal that begins its life in the water, but ends it on land - already, that's pretty weird. But, also, a lot of them are incredibly tiny and look wildly improbable. They have funny little toes, they stretch their throats into weird bubble shapes when they croak, and some of them are poisonous to the touch. I think kids from the twenty-second century might mythologize amphibians the way kids today mythologize dinosaurs.

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.

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.

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.

Eventually, humans invented agriculture, which could be understood as a way of turning the natural world into a tool for our use. There's evidence that we have been domesticating crops and animals for at least 15,000 years, adapting ecosystems to our preferred way of life.

I don't know if most people have truly taken on board what this says about our place in the natural world. It doesn't mean that humans are dominating the Earth, ruling over all of nature. In fact, it is a reminder that we are only a tiny part of nature, at the mercy of a system whose operations predate us by billions of years, and will continue billions of years after we're gone.