One need not look far to find a passionate argument that the compact city is the green city. Having more people in a smaller area results in less energy use for transportation purposes, lower greenhouse gas emissions, and greater efficiencies in the use of various resources. Cramming more people into a smaller space makes our cities more sustainable. Or does it?
A recent research study published in the spring issue of the Journal of the American Planning Association finds that – unlike today’s dominant narrative of the green city – urban form may actually have very little impact on energy use and other measures of sustainability! True or false? Read the summary article in Atlantic Cities.
Well, I’m not so sure and I’m not convinced. This research may be more interesting, more for what it does not say than what it says. I don’t believe the larger narrative about compact cities is arguing that SIMPLY by making urban form more compact that automobile use, energy use, and all the environmental degradation systematically increasing as a result of the modern economy will dramatically decrease.
How could that be the case when the key driver of these impacts (the economy) remains largely the same and intact across the urban typologies modelled? The context, that is the economy, it’s carbon-based, highly inefficient energy use, and the auto-dominant transportation system, remains essentially the same.
One big exception not mentioned in article should be noted: all of the impacts associated with “net’ greenfield development would be avoided in the compact urban forms compared to the dispersed. This will be important as we add 2B people, or 1 city of 1 million people per week for the next 40 years to accommodate the population increase (Will we effectively meet this challenge?).
I think the urban form argument is more in terms of potential for reducing impacts as we shift to fully functioning multi-modal transportation systems that are linked to land use patterns that allow satisfaction of most daily needs within the 10-minute neighborhood walk and the resulting auto-trip minimization this creates, along with a non-carbon, renewable energy based economy based on distributed, not centralized energy production. This pattern is possible only in compact urban form and a larger settlement pattern consisting of multiple compact settlement nodes effectively connected via the internet and the multi modal transportation system. Such a settlement pattern is not likely to function effectively in a low density, sprawling typology. In addition, the benefits are less about lower energy use and more about choosing to create desirable lifestyles and communities instead of structurally imposed hour or more daily commutes for everyone from the nursery school child to the parent.
With an increasingly hot, flat, and crowded planet, the nature of urban form will become determinant, in combination with technology, in creating livable, vibrant, vital, prosperous communities where population and congestion do not destroy the urban and social fabric and economic possibility. In increasingly crowded environments, the car, whether single or multiple occupancy, becomes incapable of moving the volumes needing moving. Traveling the long distances and complicated spatial patterns that are normal in today’s suburban day may not even be possible in a hot, flat, and crowded world if we get the settlement pattern wrong.
The urban planning fatal flaw in the research design in the article referenced above is that the independent variable (urban form) had little causal relationship with the associated variables of interest. Thus, variation in the independent variable did not explain variation in other variables, which likely varied more by exogenous population levels than per capita or per capita per square meter factors. In addition, Peter Calthorpe has characterized the present design of many Asian cities as dense sprawl built on a super block template that does not allow for the fine grained local development required for making good places nor providing walkable districts once regional transit destinations are reached. This pattern further reinforces dependence on automobiles or other mechanized modes of transport that only work well in low-density environments. It also crowds out any presumed green effect of “density” other than some amount of avoided greenfield development compared to low density sprawl.
The economic fatal flaw in the research design is presuming that sprawled settlement patterns somehow reflect near-enough perfectly competitive prices absent distorting externalities to legitimize the pattern as the competitive enough “preference” of the market. Unfortunately, 50 years of economic research has proved otherwise. If current prices fully reflected real resource costs, we’d be paying $12/gallon or more for gas, much higher electricity and water rates, much higher prices for vehicles, much higher prices for residential development that has been run at a net loss to local governments for 40 years and which has been subsidized through the fiscalization of land use (think local competition for big box retail), much higher prices for all development if the subsidized transportation costs were included, etc. One could go on.
Finally, people want communities, yet the market commodity available for purchase is simply a house in a subdivision produced by a developer of housing not a developer of fully functioning communities. Thus, all sorts of distorting behavior results (flights to suburbs for schools and security, not so much the “American dream house” as we would be led to believe, etc. Until we take back the goal we are seeking from the market, and then use the market as a powerful but often flawed institution for resource allocation in achieving goals, we will continue to create flawed places without understanding why. The flaws can only be magnified as we progress along the +2B population transect over the next 40 years. We have an opportunity to get it right if we understand, plan, and develop those future cities now. Further benefit can be harvested from developing associated strategies to reweave the urban fabric of existing cities and places. These are the challenges we face associated with urban form that the cited research misses.