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.

A lot of environmental and biological science depends on technology to progress. Partly I'm talking about massive server farms that help people crunch genetic data - or atmospheric data. But I also mean the scientific collaborations that the Internet makes possible, where scientists in India and Africa can work with people in Europe and the Americas to come up with solutions to what are, after all, global problems.

In fact, the early demographer Thomas Malthus believes that the only way the human population would ever check itself was by running headlong into a disaster, like a pandemic or famine. Sometimes we get so frustrated with the slowness of human political processes that we wish a giant flaming rock would solve the problem for us.

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.

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.

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.

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.