Alex Steffen: We Can’t Avert Climate Change Without Dense Cities

Alex Steffen goes by the title “planetary futurist,” which makes me realize I should probably spruce up my title to something that makes me sound like I should be wearing a cape, too. What he does is write about sustainable cities, on for seven years and more recently in his book, Carbon Zero.

He just gave a TED talk about how to make cities more sustainable. And while he’s primarily looking at climate impacts, he pretty conclusively dismissed the notion that the problem can be solved with clean fuels.

“We tend to seek simple answers,” he said. And so if we assume the problem is fossil fuels, he said, we also assume that “the answer must be to replace fossil fuels with clean sources of energy. And while we do need clean energy, I would put to you that by looking at climate change as a clean energy generation problem, we’re setting ourselves up not to solve it.”

With a rapidly urbanizing planet and eight billion people projected to live in or near cities by midcentury, Steffen asserts that it may just not be possible to generate enough energy to power all those cities – if those cities continue to look like the ones in the developed world today, anyway. The solution, he said, is density.

“There’s a direct relationship between how dense a city is and the amount of climate emissions its residents spew out into the air,” Steffen said. “Denser places tend to have lower emissions.”

Source: ##

You know the reason why: you don’t have to drive as much if everything you need is close by. Passenger travel accounts for more than 70 percent of U.S. transportation emissions. Steffen says that a city doesn’t need to increase density everywhere – just a few “hyperdense” hotspots will make a big difference, having a sort of “tentpole” effect that raises the density of the whole city.

“What we see when we get a lot of people together with the right conditions is a threshold effect, where people simply stop driving as much and increasingly, more and more, if people are surrounded by places that make them feel at home, people give up their cars altogether. And this is a huge, huge energy savings. Because what comes out of our tailpipe is really just the beginning of the story with climate emissions from cars. We have the manufacture of the car, the disposal of the car, all of the parking and freeways and so on. When you can get rid of all of them, because somebody doesn’t use any of them, really, you can cut transportation emissions as much as 90 percent. “

People are embracing a “walkshed life” where the idea of the  “dream home” has given way to the “dream neighborhood,” Steffen said.

17 thoughts on Alex Steffen: We Can’t Avert Climate Change Without Dense Cities

  1. Just so it’s clear, the stats above are (presumably) for the metropolitan regions, not the cities proper. If they were, San Francisco would be 66 people/hectare, and NYC would be 106, where Tokyo is above. Energy usage would presumably be different too.

    In fact, the highest density figure Wikipedia gives for Tokyo (“Tokyo Metropolis”) is 58.5 people/hectare, so I guess this graph is using a smaller part of Tokyo.

    Anyway, the moral of the story is that density statistics depend a lot on where you draw your boundaries.

  2. Like baklazhan below, I also pick a nit with labeling Bay Area stats as “San Francisco.”  Also, the stats above are pretty darn old — 1989.  Neither interfere with the validity of the point, that density reduces transportation energy consumption. Hong Kong is one amazing place in that regard.

    Hey, I want a cape that says “Planetary Futurist,” too.

  3. Even if it’s not the metropolitan region, Tokyo proper (“Tokyo Metropolis”) includes a lot more than just the traditional central 23-wards (it’s a really weird shape too), and some of the outlying areas are very not-dense.

    The density of the 23-ward area is about 15000 people/km^2 (150 people/hectare).

  4. I agree.  But the cities have to be made clean and sanitary.  Density bring people very close to each other, and there are health risks associated with that.  Health and sanitation systems must be improved to be efficient and more effective.

  5. So let’s sum up …. Pack multicultural populations people into cities in the millions, get rid of cars and you get rid of a lot of the pollution that is causing whatever climate change may be occurring.

    Half of the world’s industries are related to the transportation industry …. you know …. the mining for aluminum and steel for engines and transmissions, wheels, brakes, … the oil industry to produces al the plastic parts for dashes and bodies … the all the wiring and computer technology for the electrical and electronic systems …. the gas and oil industry for  the fuels and lubricants … all the sales jobs in-between … all the shipping industries to move all those parts and products and raw materials ….


    So pile up all those unemployed people in massive cities with nothing for them to do to be productive and pay taxes … buy food pay rent etc. and the world will look a lot like London England has looked the past few nights …. 

    Mad Maxx was a documentary.

    What an idiotic suggestion that we all just give up industrial high tech jobs and support massive urban population by selling coffee and croissants to each other.

  6. Further to … the excavation and road building jobs, all the businesses along roads and highways …  yes …. rats in a maze …. nothing to do …. like a holding tank for pointless protoplasm …. what the hell do you thing humanity is … a freaking ant colony?

  7. Hmm. I don’t think his argument necessarily indicates that giant cities are what’s needed. Amsterdam and Copenhagen are pretty small cities. I think density doesn’t necessarily imply a megapolis, but it does imply a certain set of conditions: transportation options that are both more energy and more *distance* efficient (these types of transpo systems too are major industries); social norms that support those choices; regional and national policies that disfavor sprawl; land use prices that disfavor sprawl; and industries more divided between urban and rural (so less in the suburban belts). 

    The industrial jobs that support the car-centered economy have been going away for years, unless you live in a place where production has moved (temporarily, y’all!) because wages there are lower for now. High tech workers favor cities or telecommuting.

  8. Because we have utterly not prepared for peak oil, a lower energy future awaits us all. Over the next two decades the cities and regions that produce GDP with the least energy input will be the most successful. Far flung suburbs will be abandoned; areas with high energy use for air conditioning will decrease drastically in population. Cities and regions that can get their work force to work each day in a low energy way will prosper. Countries and regions that were smart enough to create jobs by building out high speed rail will have a competitive transportation backbone. Those that spent their money maintaining extensive car-based infrastructure will see roads fall into disrepair or turned to gravel.

    Air travel is likely to become an elite activity and will only be between major metropolitan hubs. If we are smart, we will reserve the oil we have left for plastics and heavy farm machinery rather than squander it in 23% efficient internal combustion engines, but squandering seems to sum up our current way of life.

    Holding onto obsolete, inefficient technologies and denying the reality that faces us in the name of “preserving jobs” that are already dead men walking will get us nowhere. Cities, regions, and countries that adapt to circumstances will be the ones with jobs, decent housing and pleasant standards of living.  It is a peculiarly American prejudice that cities are necessarily full of poverty and squalor and are unpleasant to live in when the briefest visit to Paris, Hong Kong, New York, San Francisco, Amsterdam, or, yes, London, will show you that this is not true. The riots in London and other small cities in England are not due to urban living, they are due to inequalities of wealth and the government there placing the priorities of banks and bankers over the common people. Yes, this movie may be coming to a screen near us as well.

  9. My intuition is that higher density leads to lower energy use, but I don’t think this chart does a very good job of making the case.

    First, it does not control for wealth or income.  Richer people tend to use more of everything.  These are all “first world” cities, so as a first order approximation it should be ok, but we can conclude there is a meaningful difference between New York and Perth without controlling for the relative incomes?  I don’t think so.

    Second, it does not account for the energy consumed getting goods from other places to the city in question.  A sprawling city located right next highly productive agricultural and industrial areas may use less energy than a dense city on an island that has to ship or fly everything in from far away.

  10. @12c004b3005a4c8761c0daa5de6fa27d:disqus , you need to chill out buddy.  Increasing density is a necessary step to decreasing our emissions and impact on the environment.  This is the future and it’s a part of progress, and I’m pretty sure it’s not going to happen in a day so you can stop freaking out about everyone losing their jobs.  Think about how people felt when technology evolved and machines/robots started taking over people’s jobs, yeah they freaked out but guess what, they went on to other things and we’re still fine today.  

  11. Density *can* be good, but is not universally good.  There are alot of unmentioned caveats to its benefits.  For instance, prior to increasing density.. infrastructure must be created that allows people to *easily* get around without cars.  Without infrastructure in place, you will just create more traffic, congestion, etc which will make pollution WORSE not better.  Density done wrong is bad, bad, bad… and this is what I see mostly in LA.. bad density.


  12. We’re actually at a crux right now anyway. Much of the automobile-centered infrastructure is nearing its end of life. Instead of spending trillions on something which isn’t sustainable in the long run anyway, it makes more sense to just let it decay. As roads to far flung exurbs disintegrate to the point of being useless, the communities they serve will be abandoned. No real loss there because most of this construction is cheap tract houses which will probably need extensive repair by the time the roads fail. Let nature have the land. It’ll take decades for sure to undo the mistakes of the past, no arguing that. We just need to change policy now to stop subsidizing a lifestyle which is doomed no matter what. Even if some form of ultra cheap, renewable energy appears, fact is spread out living is far too costly in terms of infrastructure per capita. It’s not even healthy for the inhabitants, given that obesity rates have tracked automobile use.  If the inhabitants had to pay the true cost, most couldn’t afford it. Those who wish to have lots of space, and no neighbors, should be prepared to go off-grid. We just can’t continue to have what is basically a lifestyle with urban amenities, but at the population density of farming communities. In the past, spread out, far flung settlements were always by definition self-sufficient. We need to return to that model.

  13. @2555783a6f62598b6aadd2d882a4830f:disqus :  maybe you’re onto something.  Perhaps we should also restrict people from living in non-temperate climates… like the North, Northeast, and Southwest… because all of those heating and cooling costs are also unsustainable.  We should force everyone to live in coastal California or Florida so no-one has to run the AC/heater.

    Plus, if you have good weather all year round, people won’t get fat because they can exercise all the time.

    Perhaps we should also restrict births.  Overpopulation creates more demand for land, food, infrastructure and energy.  There should be gov’t regulation on that, too.  We can take a play out of the Chinese playbook.

    You’re really onto something, Joe.

  14. True Freedom-lighten up.  I can’t stand it when people draw all sorts of illogical conclusions from one statement.  There isn’t a place on the planet where climate is good enough that you don’t need some form of climate control.  I would personally find California too hot, and would hate the lack of distinct seasons.

    And there’s a world of difference between forcing people to do something, versus making it less attractive by simply making them pay the true costs.  Without government-subsidized roads, the mortgage interest deduction, and general government transportation policy skewed towards the automobile, living spread out in suburbs or exurbs would cost far, far more than it does.  You would only be able to live in the suburbs if you were fairly well off because you would have to pay the true costs of all that expensive infrastructure which only serves relatively few people.  There’s no reason government should have subsidized suburbia any more than it should subsidize Trump Tower so the middle class can live there.  Spread out living is inherently much more expensive and energy intensive.  There’s no way around that.  It can only continue if government continues to take ever increasing amounts of money from cities to subsidize suburbia.  I personally can’t think of any moral or logical reason to continue this same policy which has put us in the mess we’re in.  Besides, spread out living isn’t even healthy for the inhabitants.  Obesity rates have tracked automobile usage for a long time.  And then there’s the geopolitical consequences of a way of life heavily dependent upon cheap energy.

    Like I said-you want low density, then be prepared to pay much more for it and/or to be as self-sufficient as possible.  If I asked you to bankroll a lifestyle I couldn’t afford you would be the first to complain.  Well, it works both ways.  It’ll cost less in the long run to just let the suburbs/exurbs and the roads serving them decay, than it will to continue to prop them up when long-term they’re dooomed anyway.  And this isn’t even because of climate change.  Rather, it’s because of the sheer expense of building roads/sewers/power lines serving fewer people per capita.  You just *can’t* have urban amenities at the density of farming communtieis without things getting frightfully expensive.

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