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 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.

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.

Survivor species tend to have huge populations, so they can afford to lose many individuals and still survive as a species. They also tend to be small. If you're small, you need less food - which is great in a situation where famine is everywhere.

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.

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.