Alex Steffen gave one of the keynotes, at the first SXSW Eco Conference this fall, talking about good cities as the single best leverage point we have in reducing GHG emissions. It’s broadly the same collection of ideas as his forthcoming crowdfunded book Carbon Zero: A Short Tour of Your City’s Future. Looking forward to its eventual release.
A series of posts from the NRDC on how good, human friendly cities are actually the most sustainable places for people to live, in contrast to our fond fantasies about the country, and especially the suburbs.
How important is Location Efficiency? Median US home price: $175k. With a traditional 20% down 30 year mortgage, total loan payments amount to about $350k. Utilities over the same timeframe are around $75k. And the cost of commuting from suburbia? Roughly $300k! This is in general agreement with the energy (as opposed to financial) analysis recently published by the EPA.
TED fellow Viraj Puri talks about his Brooklyn rooftop farming startup. Gotham Greens has ~1500 square meters of hydroponic greenhouses producing herbs and salad greens in a very controlled environment… somewhere between a farm and a manufacturing facility. The system is solar powered, and can operate all year long. They currently produce ~100 tons of food a year, and they believe the business is viable at least in the urban foodie context. I was happy to see Puri readily (repeatedly) admitting (or even pointing out) that the system cannot scale up sufficiently to provide a large proportion of the city’s overall food requirements. This is in stark contrast to the idea of Vertical Farming, which is clearly bunkum — once you’ve covered the roofs with greens, there’s no more farming to be done unless you pipe in light somehow, which is much less efficient than simply farming where the light is naturally.
Just out of curiosity… I wonder how much food could be produced in Brooklyn at full capacity? And roughly how much does the city eat? The land area of the borough is 183 km^2 and it has 2,500,000 residents, or roughly 75 m^2 per person. Their production of 100 tons/1500 m^2 is roughly 66 kg/m^2 per year. So if the entire area of Brooklyn were producing like this greenhouse, you’d get nearly 5000 kg of food per person per year. The average American consumes about 1000 kg of food per year, so if you were able to use 20% of the borough’s area, you’d be close to meeting demand… at least by mass. Gotham’s 59kW solar array probably takes up ~590 m^2 (100 W/m^2 is typical of solar cell power production) and only provides part of the operation’s power. Probably there’s other infrastructure too that’s not actively producing food, so say they’ve got about half their total area dedicated to actual plants… then you’d need to get up to 40% of the land area being utilized to get 1000 kg of greens per resident per year. However, most of the 1000 kg that we actually eat is a lot more energy dense than lettuce. I wonder how many calories per m^2 one can get out of these setups, and what the most productive crops would be? Honestly I’m surprised at how large the potential production is. I wonder what the actually available rooftop area is?
According to this EPA study, regardless of the type of housing, living in an area with good transit access saves more energy than building a “green home”. Of course, living in a mixed use, transit accessible apartment that’s also energy efficient uses the least energy, but it’s important to realize how limited the potential for cost-effective energy efficiency is in a sprawling suburban context.
The Boulder Blue Line has a short post entitled This Law Cannot Be Repealed by Albert Bartlett, who is an emeritus professor of Physics at CU, and who is most well known for speaking about the absurdity of “sustainable” growth and what exponential growth really means. He’s also one of the original architects of Boulder’s “Blue Line”, which has limited growth beyond certain boundaries within the city and county.
I agree with Bartlett on a lot. Unconstrained population growth is undoubtedly, in a global context, an epic disaster. In his collection of essays Brave New World Revisited, Aldous Huxley noted of overpopulation that “Unsolved, that problem will render insoluble all our other problems.” Similarly, the unconstrained geographic growth of towns and cities is a catastrophe, resulting in very low-density, car-dependent development which exacerbates the consequences of population growth by increasing the amount of resources that each individual consumes, in terms of land and energy and material goods.
Urban density and good public space make scenes like this possible.
I recently watched Code 46 again. When I first saw it a few years ago I didn’t like it very much, but this time it seemed more interesting. The storyline doesn’t hold together very well, and from a scientific point of view there are some painful gaffes, but it’s at least attempting to explore some important present and near-future issues, which is more than I can say for most science fiction films. That makes me sad, since I feel at its best, science fiction helps us understand how we interact with and relate to technology, and how technology changes the way we interact and relate to each other. The fact that there’s so little mainstream science fiction trying to do this today is frightening. We’re just blindly stumbling forward into the darkness. Maybe the best thoughtful sci-fi I can recall from the recent past is Gattaca, which depicts in a very stylized way a future society which is starkly divided between those who are genetically enhanced and those who are not. Gattaca is pretty clearly unconcerned with the details as opposed to the implications of its premise, and that makes it easier to gloss over whatever issues it has. It’s less clear that Code 46 is this self aware, but at least on a second viewing, I was willing to give it the benefit of the doubt. Be warned, there are spoilers below.
Kim Stanley Robinson gave a fun talk at Google a couple of years ago in which he brought up the possibility of large, slow, wind powered live-aboard bulk freighters, among other ideas. I was reminded of it by this post from Alex Steffen. Especially for commodities like coal, grains and ore — non-perishable goods that get carried in bulk carriers — what matters is the net flux of materials and the predictability of supply. More (or larger) slow ships can deliver the same flux as fewer high speed ones. International contracts for these goods can span decades. If fuel prices became a significant portion of their overall cost, it would be worthwhile to make this kind of ships-for-fuel substitution. However, it turns out that fuel is a vanishingly small proportion of the overall cost of most internationally traded goods.
Our neighbors in Pasadena moved back to Thailand, and packed their entire household into a single half-sized shipping container. The cost to get it from their home in SoCal to their home outside Bangkok was $2000. Their combined airfare was probably a larger fraction of the cost of moving across the Pacific. You can get a full-sized shipping container moved from point A to point B, anywhere within the global shipping network, for several thousand dollars. If your cargo is worth significantly more than that, then you don’t have to worry about Peak Oil destroying your business. For a typical container carrying $500,000 worth of goods, the shipping costs (not all of which are related to fuel!) represent about 1% of the final costs of the goods. If fuel prices were to go up by a factor of ten, the shipping costs would still only represent 10% of the overall cost. This would have an effect on business, to be sure, but it would not cause global trade to collapse.
A good piece from The New Yorker on what makes dense urban areas intrinsically better for the environment than suburbia or back-to-the-land fantasies. More people closer together need less transportation to go about their daily lives. High density buildings need less energy to stay comfortable inside because they have less surface area for the enclosed useful space. More resources can be effectively shared when lots of people are close together. The author, David Owen, has a whole book on the topic, entitled Green Metropolis: Why Living Smaller, Living Closer, and Driving Less Are the Keys to Sustainability. Cities have their problems, but often they aren’t the result of density directly. Poor air quality in cities, for instance, is almost entirely the fault of motor vehicles.
Another thing that cities do is make revolution possible. Which is interesting to think about, given that more than half the humans now live in cities, many of them in relatively poor, relatively un-free conditions.