Hello everyone and welcome to the Mindscape Podcast. I'm your host Sean Carroll. If you remember back in the early go-go youthful days of Mindscape,

we had Jeffrey Weston in episode five, Jeffrey's next-prote-on complex systems and scaling from physical systems to biology to social systems.

And one of the things we talked about was cities and how the fact that human beings congregate in cities is extraordinarily helpful when it comes to generating ideas, innovation, progress.

The number of patterns per person is much higher in a city than in rural areas for example. Not just because there are more people, but even more per person.

Today, we're going to talk about cities or urbanization more generally as engines of actually protecting and preserving the environment.

So the idea is not only that is moving into cities good for human beings. We talk to each other, we experience diverse, possible outcomes, and we have good ideas,

but it's even better for the planet to have human beings in cities. This can seem paradoxical, but I think that we'll try to show you that it's not.

And I should say also, we're not trying to have an agenda that cities are the best. I happen to live in a big city, but I appreciate all the listeners, no matter where they are, farms, houseboats, mountain tops.

You can listen to Mindscape from anywhere you want. Today, we're going to talk about ecology, nature, conservation with Joe Walston.

Joe is a conservationist and naturalist at the Wildlife Conservation Society where he's the vice president for field conservation programs.

And Joe has spent numerous years working on conservation of nature in Africa and Asia and other spots around the world. So he's not exactly an anti-nature city boy, but he's done the science.

He's looked at how human growth has been affecting our planet. Obviously, it's not all good. Climate change, pollution are very, very real.

But urbanization, Joe claims, the fact that people are being concentrated in cities gives us a new way to live in harmony with nature, really.

If you worried about population growth, for example, the population of the earth is still growing, but the rate of population growth is dramatically slowing. It peaked in the 1960s.

And much of that is because people have moved into cities and are having fewer children there. We might be undergoing a phase transition from an exponential growth phase, where we're just having more and more people, to a new phase where there's a certain fraction of the earth taken up by human settlements, but it's mostly urban.

And nature and all the different species on earth can survive in harmony with us at the same time. That's what we're going to get into. We're going to talk about all those issues. It may or may not be true, but it's certainly food for thought.

As a reminder, you can support Minescape by pledging on Patreon at patreon.com slash Sean M. Carroll. And I very much appreciate everyone's support. Thank you for all those who have pledged. And with that, let's go.

So, I'm going to start with the first question.

Joe Walst, and welcome to the Minescape podcast. Thanks very much.

So, I think it's because population is something where people have talked about it, right, resources, environmentalism, urbanism, all these things we're going to talk about, people have preexisting ideas in their head. It's not like talking about the Higgs boson, where you can just say anything.

So, before we go back and lay the groundwork, why don't you give away the punchline? What is the sort of elevator pitch for your proposing a fairly new way of thinking about some of these issues?

The punchline would be that for the whole entire life of ourselves and the actual environmental movement, the earth has been on a steady decline in terms of nature. Nature has been on a decline.

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