My first goal would be to reduce the perturbation in the carbon cycle. That would mean using carbon neutral sources of energy, and changing our agricultural practices to be less disruptive and polluting. I'm not talking about a policy here so much as changing the way our infrastructure works. That's why I'm so fascinated with changing the way we build cities, because they are the most developed forms of physical infrastructure for human habitation.

There are plenty of publicly-funded organizations and nonprofits that are trying to develop GMO crops that could help feed people in developing nations by producing disease-resistant or drought-resistant strains of staple crops like cassava or bananas.

The fact that we have been able to perturb the carbon cycle with our industrial revolution is evidence of how vulnerable we are - because when we destroy our environments, we destroy our food and energy supplies. In short, we destroy ourselves.

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.

Cities should function more like ecosystems, or even metabolisms. When we build, we should be thinking about how we can integrate into the ecosystems around us, but without sacrificing all the niceties of civilization like good restaurants, concert halls, and high-speed Internet access. I'm saying that partly tongue-in-cheek, but I'm also deadly serious. The future of technology is sustainable ecology.

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.

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.