Somehow, "futurist" seems like a fun thing to put on a business card, and that's just what Alex Steffen is--a leading thinker about where Earth is headed, and about sustainability in general. Until the end of last year, Steffen was the executive editor and co-founder of Worldchanging, a publication that became the second largest sustainability site on the Web, as rated by Nielsen Online in 2008, covering everything from flying disaster-relief robots to urban sustainability in Shanghai.

Steffen is the editor of the just-released revised and updated edition of Worldchanging: A User's Guide for the 21st Century, which covers carbon-neutral homes, ecotourism, the sustainable food movement, and more. Here, he discusses the fate of the planet, why greening the suburbs is a bad idea, and Edward Sharpe and the Magnetic Zeros.

What do you say when people ask you, "What do you do?"

Generally, I tell them I'm a writer and public speaker. If they ask what I write about, I say "planetary futurism." Then they either stop asking questions or we have a really interesting conversation. Cabbies in particular seem to like discussing the fate the Earth.

What new idea or innovation is having the most significant impact on the sustainability world?

The fundamental importance of city-building. More than 200,000 people are added to the world's urban population every day: within four decades 70 percent of humanity will live in large cities, and almost all of humanity will live within a day's travel of one. Cities generate most of the global economy, and most of its energy use, resource demands and climate emissions. How we build cities over the next decades will largely determine whether we can deliver a bright green future. We can now see that urbanization and sustainability must become synonymous in the 21st century.

What's something that most people just don't understand about your field?

The scope, scale and speed of the problems we face. There is still a sense that the crisis is decades away, happening to other people and just one set of problems among many. In reality, we face an imminent and all-consuming crisis, involving scores of interconnected challenges and it's unfolding all around us.

On the other hand, I also think most people don't realize how great a set of solutions we already have at hand, and how much our lives could actually improve while we tackle these problems. A cautious optimism makes sense, despite all the bad news.

What's an emerging trend you think will shake up the sustainability world?

The suffusing of urban space with technology. If good neighborhoods offer access to the stuff of life through proximity, rather than mobility (things are already close at hand, so you don't need to drive to get them), technology increases that access by an order of magnitude by making it easier to connect, track, share, meter, and collaboratively use objects and spaces. I think we're only just beginning to glimpse the implications of all this.

What's a sustainability trend that you wish would go away?

Shallow redesigns of suburban life. You see a lot of proposals these days that seem to suggest that all that open space is perfect for farming, or that we can power our McMansions and cars with solar panels, so even the suburbs can "go green." The brutal reality is that newer, more sprawling suburbs--and especially the cheap boom-years exburbs--aren't just a bit unsustainable, they're ruinously unsustainable in almost every way, and nothing we know of will likely stop their decline, much less fix them easily.

What's an idea you became fascinated with but that ended up taking you off track?

I spent a couple years thinking about systems for helping us better understand the real impacts of our daily choices on our ecological footprints. But our daily choices are largely inconsequential next to our larger system choices. Sure, eating less meat, buying less stuff, and flying less often are all helpful. But living in compact neighborhoods, getting rid of our cars if we can, working for companies and voting for candidates who will fight to bring us clean energy, transit, better farming, smarter buildings and more sustainable infrastructure--those are the transformative actions.

Who are three people you'd put in a sustainability Hall of Fame?

Jim Hansen of NASA, who's probably done more than any other scientist to alert humanity to the true magnitude of the dangers we face. David Brower of the Sierra Club, who lead the American environmental movement into a sense of planetary responsibility. Al Gore, who (despite a decade of vicious attacks by his opponents) really brought the need for climate action to mainstream America.

What other field or occupation did you consider going into?

I'm fascinated with design. I realized early that I had no talent in that direction, but I love talking with architects and designers about what they do. I appreciate applied creativity as a source of pleasure and meaning.

What website or app most helps you do your job on a daily basis?

Currently, I'm obsessed with Kickstarter, the crowd-funding platform. I'm about to launch an experiment using it, to see if a small group of people can quickly fund, publish and promote a small book on carbon-neutral cities in time for Earth Day. The growing capacity of the Net to enable like-minded people to swarm together to accomplish creative tasks is a source of optimism for me.

What song's been stuck in your head lately?

"Home," by Edward Sharpe and the Magnetic Zeros. My girlfriend and I fell in love to that song. It's been happily stuck in my head for a year now.

Image: Courtesy of Alex Steffen