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Great places: dense, wired, and sustainable

2011 July 12
by David Roberts

Note: this post originally appeared on Grist, and is reprinted here with the author’s permission.

Part of what makes great places great is ecological sustainability. So what’s the best way to reduce our per-capita resource footprint? Typically you hear one of two stories. One is about technology: making gadgets, appliances, vehicles, and factories leaner and more efficient. The other is about conservation, i.e., consciously choosing to use less stuff.

Neither of those stories captures the biggest opportunity and the best strategy for reducing consumption and waste, which is, quite simply, density. Density is the sine qua non of sustainability. Generally speaking, if you’re an American living in a suburban or rural area, it doesn’t matter if you live in a green home, own a Prius, are vegetarian, have a compost bin and backyard chickens — your footprint is bigger than someone living in an efficiency apartment in Manhattan.

Why is this so? There are many reasons but the main one is simple math: living closer to other people enables you to own less and share more. You share the streets, the cars (taxis), the subways, the ports, the office buildings, the lights, the heat. Another way of putting it is, with more people closer together, a given unit of resources can go farther: a unit of space, of power, of transportation or water infrastructure. Density is inherently more efficient. (For more on this see David Owen’s Green Metropolis or this recent piece from Bryan Walsh.)

To say that density is green is not to say that all cities are green in all ways. (Obviously!) It is rather to say that when we look at pathways to radical, non-incremental change in our resource efficiency, all roads lead back to density. Nothing else has as much potential.

Consider: What’s the main barrier to sharing more stuff and owning less? Well, it’s a pain in the ass. Buying stuff is easy; indeed, the best minds in America are devoted to making it easier. But coordinating with other people to share stuff is time-consuming and often inconvenient. The main barrier to sharing is transaction costs. Density, bringing people into close physical proximity, is one way reduce those costs. Another is information technology. The two together make a modern, bright green city.

IT can do two things. One, it can make the invisible — in this case resource flows — visible. And two, it can reduce the time and labor costs of managing those flows. Here’s how I described it in a post last year:

[Efficiency] doesn’t just mean more efficient appliances and cars, but more efficient metropolitan systems. Sensors and microchips are getting cheaper so fast that pretty soon it will be possible to wire everything. Information about where energy is being generated and consumed, where traffic is congested, which parking spaces are occupied, where fresh and wastewater are flowing and how much, will be available at every node in the network. With that kind of information and the computing algorithms to make sense of it available to every building, vehicle, and consumer device, it will be possible to institute variable pricing for everything from energy to congestion to parking to water. Efficiency will be infused into the system rather than tacked on.

Admittedly, that’s some futuristic sh*t. But the idea is to identify an end goal, so we know which direction to travel with our incremental steps. To show how it might work for transportation systems, let me quote (at some length) a review I did of a book called Reinventing the Automobile: Personal Urban Mobility for the 21st Century:

It begins with the Urban Small Vehicle (USV), which can best be described as a computer with wheels. Because it will be electric — run, like laptop computers, on lithium ion batteries — it will be simpler and more modular than cars with internal combustion engines: “A traditional car requires elaborate systems of reservoirs, tubes, valves, and pumps to distribute the gasoline, oil, water, air, and exhaust gases, but a battery-electric automobile replaces most of these complicated distribution systems with wires connecting the batteries to the wheels.”

USVs will be equipped with an array of sensors and controllers that enable them to maintain steady distances from other cars, avoid crashes, and even pilot themselves. … Far more than any advanced engine or materials ever could, this situational awareness will allow the vehicles to be smaller, lighter, less armored, and more energy efficient. …

Where the vision tips over from cool-for-car-nerds into mind-blowing is not in the car itself but in how it’s connected to the power grid, other cars, and the city around it. Most cars are parked about 95 percent of the time. All those idle batteries add up to considerable energy-storage capacity. …

The authors envision USVs converging with other technologies — rooftop solar panels, small wind turbines, geothermal heat pumps, cogeneration systems, large-scale batteries, smart grids — to create a new kind of power system in which cities are generating, managing, and distributing all or most of their own electricity. …

Moreover, all USVs will be GPS- and Internet-connected. Think of the location-specific services an iPhone offers, from maps and directions to restaurant suggestions to hyper-local news. Now imagine a similar range of apps for a vehicle that’s receiving real-time information about road congestion, parking availability, and the latest box scores. Imagine the benefit to traffic planners of having information about the location and trajectory of every vehicle (encrypted, say the authors, but their discussion of privacy issues is cursory at best).

This “Mobility Internet” could lead to the same kind of innovation unleashed by the Internet itself.

What density plus IT (DIT?) can do for transportation it can also do for power. Power generated close to dense loads reduces transmission costs. It also enables the capture of waste heat, which is a big deal — see Bill McKibben’s great piece, “The Unsung Solution.” IT-infused smart grids can insure that the power produced is used more efficiently. For more on the power angle, check out a piece I wrote for Scientific American called “Local power: tapping distributed energy in 21st-century cities.” Here’s what it looks like for a Swedish neighborhood called Hammarby Sjöstad:

Hammarby Sjöstad< Hammarby Sjöstad’s “eco-cycle” >

Anyway, if density is at the heart of ecological sustainability, then it is at the heart of great places.

This can be somewhat uncomfortable to an older generation of environmentalists. There’s always been a strain of pastoralism in the U.S. green movement, a back-to-the-land romance that sits uneasily with the bright green focus on high-tech urbanism. Big cities were horribly dirty and unpleasant for a very long time, and that shaped generations of attitudes. It shaped a movement that came together around love of untouched wilderness and conservation of land and species.

But density is the imperative. Pastoralism is only sustainable if you cut the global population down to about a tenth its current size and/or convince hundreds of millions of people to forego the amenities of modern life. Neither of those seem likely, short of global catastrophe. More likely, the future will be crowded and resource-strained. The only way past is through, and that means putting our collective intelligence (and computing power) toward the conundrum of how to make it pleasant to live close to a bunch of other people and share a bunch of stuff with them.

On the bright side, this opens up all sorts of new routes to ecological activism. Right now the tools of activism are limited: march, picket, petition, write your congressperson, lobby, donate. It’s a narrow-band thing, a lifestyle that by nature is not going to attract all that many people.

But what if ecological activism meant figuring out how to make living together more fun? What if “going green” meant making cities more sociable, exciting, rewarding places to live? What if, instead of making people feel guilty and give up things they like, your job as as a green activist was to delight them?

That sounds like something a wider range of people could get involved in, something that would attract artists and entrepreneurs and tech geeks and forward-thinking politicians. It sounds like something suited not to a “special interest” but to a rising political generation finally ready to live in the present.


David Roberts is staff writer for Grist. You can follow his Twitter feed at

11 Responses leave one →
  1. monster permalink
    July 12, 2011

    sounds good but what are you willing to sacrifice.

  2. RossB permalink
    July 12, 2011

    I agree with the city part of the article, but I’m not sure about the car part. I agree that the biggest problem is congestion, but I’m not sure the cars you are talking about could actually solve that problem. I can have the most sophisticated computers and algorithms in the world, but I can’t get a car from Tacoma to Everett in an hour during dinner time. One possibility is to have cars dock into larger system. Maybe that’s what you are talking about. If so, then that makes a lot of sense, but I don’t think they will be able to drive themselves on roads for a very long time. Computers aren’t very good at recognizing things (I know they’ve made good progress, but they still aren’t that good). That is why robots haven’t replaced everyone on the assembly line (a robot is really good at putting “this” over “there” but it can’t figure out exactly what “this” is or where “there” is).

    Having electric cars that ride on rails (or dock with other cars on a rail system) makes sense, but it runs into the same problem that public transportation has run into for a long time: it takes a lot of investment to get it running. Conventional cars are popular because they can be driven anywhere. You can drive downtown, to the other side of town, or to the mountains (with quick stops to refuel along the way). A pod system could deliver all of that with much better efficiency, but I think it would take a long time to get rolling. Once it did, then the information technology you mention would be a great boon to the system. You could get into your pod car, into the rail system, type in your destination and the car would get you to the other end. At that point, you could leave the rails and drive the (less populated) road. Along the way, your pod connects directly with the other pods that are going the same direction, thus increasing overall throughput.

    A much more conventional system would be to leverage existing technology with more sharing. Car pooling is an obvious potential breakthrough. These are problems that computers are really good at. It seems quite likely that you could just enter in your current location, where you want to go, and the computer would tell you where to meet your passenger or driver.

    This could easily compliment public transportation and even extend to the boonies. If I want to go hiking at Mount Rainier this weekend, I will get in my car and drive. At best, I’ll be able to share a ride with someone. But why can’t I ride high speed rail to Tacoma, then share a ride? We would need the rail system (of course) but also the car sharing system. What is true of Mount Rainier is true of many other places as well (take high speed rail to Issaquah, then share a car).

    The obvious negative is that people don’t trust other people. People don’t want to pick up strangers. Fair enough. Such a system could also provide some level of security by providing background checks. It could also guarantee a certain number of passengers for those that want that (which would be no different that riding a bus). Security and concern for private property would be the obvious articles to overcome, but as your article suggests, great things could happen when they are.

    • Matt the Engineer permalink
      July 13, 2011

      I just signed up for <a href="http://getaround.comGetaround. It’s just taking off in SF and isn’t here yet, though they say they’ll base their next city on where the most people have signed up. If something like Getaround takes off, then you could ride high speed rail to Tacoma, then walk to a nearby car for rent, hop in and go. Though I guess you can now, just rent a car. Prices start at $3/hr for a an old beat up car to $50/hr for a Tesla. Sure, you’re still just one person in a vehicle, but it solves part of the problem.

      • RossB permalink
        July 13, 2011

        Yeah, that sort of thing looks like it could spread very quickly. It wouldn’t surprise me if it becomes so common that ten years from now people forget that it was a novelty back in the day (like the internet, cell phones, etc.).

  3. Dan Staley permalink
    July 12, 2011

    I’m interested how we’re going to recycle all the skyscrapers when cheap energy goes away and we aren’t powering lifts to the 30th floor any longer.

    • Matt the Engineer permalink
      July 13, 2011

      I don’t see elevators as ever going away. They’re basically vertical mass transit systems, and make for very space efficient buildings. There’s actually plenty of room for making them much more energy efficient – just use your motor as a generator on the way down and pump energy back into the grid. Hey look, they already exist.

      If your argument were to hold then we also wouldn’t be powering people and goods up hills anymore and we’d have to all live in valleys. And that’s just not likely.

      • RossB permalink
        July 13, 2011

        I agree, Matt. Elevators are one of the most efficient transportation systems around.

        Not to change the subject too much, but it reminds of something someone said on a blog a while ago. I think they were comparing transportation systems, and noted that on a per mile per person basis, the New York subway system really wasn’t that fuel efficient. Assuming this is the case (which could very well be, since the subways are old and spend a lot of their time speeding up and slowing down) I think it misses the point. From an economic standpoint, the purpose of a transportation system is to get you to where you can be of most value. In the past, it was to get you to the factory. Now, it is to get you to other people, so you can develop new ideas that can benefit society. New York has a very efficient transportation system (probably the best in the U. S.) since it allows so many people to so easily get in contact with other people. Traveling five miles on and old subway may not be as efficient as traveling five miles on a new light rail, but if you encounter way more people along the way, then it is a superior system. In other words, a better way to measure a transportation system is to measure how much energy it costs to meet (face to face) with other people. A typical New Yorker can easily meet with several million people (individually, not all at once) without using much energy at all (an elevator ride, followed by a walk in many instances) while a typical Seattle citizen has to spend a lot more energy.

      • Dan Staley permalink
        July 13, 2011

        If your argument were to hold then we also wouldn’t be powering people and goods up hills anymore and we’d have to all live in valleys. And that’s just not likely.

        Your argument is jumbled. Your argument mixes present and future.

        Nonetheless, we have energy-generating sidewalks too. I care about EROEI and and emergy. In the future where profligate waste cannot stand, paradigms will be different.

        • Matt the Engineer permalink
          July 20, 2011

          I think it’s fairly clear I was talking about the future. Tell me you’re not claiming that in the future nobody will live on a hill. If someone can live on a hill then they can live on a building – the energy works out the same.

          I think in an energy-limited world distance becomes more important than height.

    • Chris Stefan permalink
      July 17, 2011

      Density doesn’t have to mean skyscrapers. An area of 4 or 6 story buildings can be quite dense. See many older cities such as Paris or Amsterdam for examples.

      The bigger issue for tall buildings is not the elevators but cooling, ventilation, and lighting. From an energy consumption standpoint these dwarf the energy needed to run the elevators.

      • Matt the Engineer permalink
        July 20, 2011

        “cooling, ventilation, and lighting” Yes. One solution is to use thin buildings with spectrally selective glazing, daylight harvesting, and operable windows. Heating climates are a bit more tough, as thicker buildings will minimize skin losses but lose daylighting – looking just at energy you’ll probably want thick buildings, but weighing electricity heavier than heat you’ll still want thin buildings.

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