Judy Layzer isn’t, by any common definition, a futurist. But after a conversation with her you might feel you’ve just spoken with one.

A political scientist by training, Layzer now teaches and writes in MIT’s urban studies department, where she has become increasingly focused on sustainability and the built environment—especially the ways that that environment is going to change. The way she tells it, change sounds like possibility (however hard it may be to achieve). As she says after enumerating some of the “healthy changes and opportunities” that will result from higher energy prices, “all of this is in some ways an urban planner’s dream. It’s the way we thought people should be living anyway.”

For the MIT Sustainability Interview series, Layzer spoke with MIT Sloan Management Review editor-in-chief Michael S. Hopkins.

How do you define sustainability?

I have a definition of sustainability, one that reflects my values, which is that we have to operate within the physical and biological limits of the Earth. And within that, we need to develop social systems that are fair and economic systems that can work over time—that don’t destroy themselves and the resources that they depend on.

For me, it’s about the life support systems. I’m a Herman Daly person. I take his sustainability definition as mine.

What would you say is the generally-held public definition of sustainability?

Well, of course, everyone complains that there is no general definition. But the reason that the word works is because, like ‘community,’ like ‘equity,’ like ‘efficiency,’ it’s a political word that people define differently. You get into fights over it. But at least most everyone can agree that it’s important. And that’s politically valuable.

The conventional definition is the three-legged stool—that social equity, economic development, and environmental regeneration all are essential components, and there’s that sweet spot in the middle where they all come together. I don’t use the three-legged stool. I don’t find it useful. My preferred metaphor is the container. That is, our social and economic systems have to operate within the constraints of a healthy, resilient natural system; the natural system is the container for the social and economic systems.

But that definition is not only controversial, it’s also antithetical to the way the world is currently organized in terms of how we run our global economy. If we tried to implement my definition, it would involve a transformation of a