From Utne Reader: Alex Steffen on what it would take to make a city carbon neutral.

… the best thing a city can do is densify as quickly as it can. That needs to be  said every time this issue comes up, because it’s the only universal strategy  that works. That’s the best-documented finding in urban planning—that as density  goes up, trip length goes down and transportation energy use goes down.

The main  question that nearly every city in North America needs to address is how to densify quickly. Once people are grappling with that, though, there are other  things people need to do to make that work: making neighborhoods walkable, with  green spaces, street life, mixed-use zoning and other qualities that make a  place livable. If you have density without that, you just have vertical suburbs.

If you live in a single-family neighbourhood and find that sentiment repellent, Steffen has a response:

(Melbourne is) growing quickly, needs to add a million people over the next decade  or two, but they don’t want that to be sprawl. So they took a digital map of the  city and blocked off everything that’s currently single-family residences,  everything that’s a historical building, everything that’s green space, working  industrial land, and other things people are vociferous about valuing.

That left  a fairly small percentage of land. But they showed that if they concentrated  density in those corridors, they could add a million people without expanding  the city at all, and it would add all these benefits, like better public transit  and such.

You can dramatically increase the density of places without taking  away things people want—and actually adding things they want but couldn’t afford  today—because the average suburb isn’t dense enough to financially support a  tram or the like. But if you add a dense core that can support that, suddenly  even the people around it, in their single-family homes, get the benefit, too.

I  call that “tent-pole density,” where extremely high density in a small area  brings up the average for a whole neighborhood, even when the rest of the  neighborhood doesn’t change. I think it’s a really important concept, one that  most people don’t get.

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And speaking of ideas, why reinvent the wheel when you can borrow someone else’s?  That’s the idea of a Living Labs Global who are sponsoring a kind of crowdsourcing for cities, where municipal governments put out an open call for solutions.

More here.