When It Comes to Sustainability, We’re Ranking Our Cities Wrong

Professor David Wachsmuth explains why sustainability rankings are inherently biased—and what we should do about it.

Courtesy Flickr User Several Seconds

A recent article published in Nature makes a bold claim: we’re analyzing our cities completely wrong. Professors David Wachsmuth, Aldana Cohen, and Hillary Angelo argue that, for too long, we have defined sustainability too narrowly, only looking at environmental impact on a neighborhood or city scale rather than a regional or global scale. As a result, we have measured our cities in ways that are inherently biased towards wealthy cities, and completely ignored the negative impacts our so-called “sustainable,” post-industrial cities have on the rest of the world. Metropolis editor Vanessa Quirk spoke with Professor Wachsmuth to learn more about the unintended knock-on effects of going “green,” the importance of consumption-based carbon counting, and why policy-makers should be more attentive to the effects of “environmental gentrification.”

Vanessa Quirk: In your article for Nature, there was a line that, for me, really summed up the crux of the argument—”Many sustainability gains are simply a regressive redistribution of amenities across places.” Can you expound upon it further?

David Wachsmuth: The idea is that so much of urban sustainability, planning, and policy in general has been aimed at relatively narrow spaces: building-code improvements to make individual buildings greener, or neighborhood-scale improvements like new bikeways, greenways—those kinds of things. There is a lot of evidence that those really make individual areas, buildings, and neighborhoods greener places to live. The problem is that our cities actually exist in larger regional, and even global systems. What happens when you make one neighborhood greener is that people value that “green” as an amenity. That means that there’s more demand for people to live in those areas. When you’re faced with a limited supply of housing and a limited supply of space in the city, that green neighborhood ends up being really highly sought after.

People who can’t afford to live there, who used to live there and can’t afford it anymore because the rents are going up, they get pushed down into other areas of the city and the region. The result is that improvements to specific neighborhoods basically boil down to concentrating a lot of good things in one place and effectively pushing people who can’t afford them out.

VQ: Is that what you refer to as “environmental gentrification”?

DW: Exactly. In order to prevent runaway climate change, we have to make a lot of changes to the way that societies and cities are designed, planned, and organized. That’s not on the scientific level, but just on the level of everyday life. A lot of the greening improvements that particular cities have are things that people in everyday life would enjoy: better bike paths, better transit access, cleaner neighborhoods. That is great. Everybody should be able to have access to nice parks. But there’s only so much money to get spent on these issues, and cities inevitably prioritize projects that are good for local economic development, and focus on downtown areas. Poor areas and more suburban areas lose out.

VQ: You can see that very clearly in New York City and the Citibike program. It still isn’t in Harlem or in Queens. It’s very much concentrated in economic centers and tourist areas.

DW: Exactly. The other side of the coin is that when you look at the cities that tend to be celebrated the most for their sustainability victories, like New York and San Francisco, these are cities that are very prosperous. They are what we refer to as post-industrial, as they don’t do a lot of manufacturing any more; they’re much more involved in finance, in service sectors, in technology areas. Part of the reason we argue that these cities look so good in sustainability terms is because we define “sustainability” much too narrowly.

Take the example of San Francisco. If you look at per capita carbon emissions, it looks pretty low. We know why that is—lots of people take transit, housing is pretty dense, etc. But as soon as you start taking into account the fact that these people who live in San Francisco are consuming an enormous amount of goods from elsewhere in the world, and doing an enormous amount of travel outside the city, the carbon footprint situation looks totally different. We have this model in our mind—as policy makers, as academics, as urban thinkers—of the post-industrial city as the most sustainable city. But that’s only really true if we ignore all the environmental impacts that cities have outside their borders.

VQ: That gets to your idea of consumption-based carbon counts. Would you mind defining that?

DW: The general way that we measure cities’ carbon footprints is by looking at all of the activities that occur within cities and finding out how much carbon is associated with them. For example, if we know that people drive this much in a given city, we know how much carbon is produced for every mile that someone drives. You add up all the things that happen in the city that produce carbon. That’s the standard way it’s done.

What we’re saying is there’s a much better way to do this. Not to count the amount of carbon that is produced within a city, but instead count the amount of carbon associated with all the consumption that occurs within the city.

For example, almost everybody these days has a smartphone in their pockets. The production of them takes an enormous amount of energy and therefore carbon emissions, but they’re basically produced in other parts of the world, mostly in China and the Far East. A normal count of carbon usage in San Francisco doesn’t account for all the computers or smartphones that people have. But if you assign the responsibility for that carbon to the people who are buying and using these products, then researchers have found that that more than doubles the amount of emissions associated with wealthy cities.

Normally we don’t count that, but we should. Because that’s part of the lifestyle in these post-industrial cities.

VQ: Right. It’s a more equitable way of looking at it. You’re assigning responsibility to the consumer and not just the producer, because obviously the producer only has things to produce if there is demand on the consumption side.

DW: When you think about it, part of the reason why wealthy cities are so wealthy is not that they removed themselves from global manufacturing, but that they occupy a very privileged position there. The banks are located in New York, the same banks that finance all the factories. It seems pretty unjust to say, “Look at how successful New York’s been at reducing carbon emissions” when New York is the center of all the global activity that pollutes other parts of the world.

New York has exported its pollution. That’s partly why we say that a lot of sustainability gains actually turn out to be “regressive redistributions.”

VQ: You say in the article that we need to control for income and lifestyle when measuring low-carbon benefits of density…

DW: Because otherwise, if you don’t do this, you’re always going to bias your measurement toward wealthy cities. Because wealthy cities have managed to climb up the value chain to do what we call the command and control functions. The corporate headquarters, the banks, the law firms—these are the activities that produce less local pollution.If you don’t take into account the fact that there’s a whole global network for the way goods and services are produced and consumed, you’re going to bias your measurements of who’s green in favor of wealthy cities.

I don’t think that there’s anything too malicious going on here. Part of the reason why we haven’t done such a good job at this is because it’s hard to do. It’s much more straightforward to count locally produced carbon emissions than to take into account the regional and the global context. The problem is that we need to do it, if we want to have a truly accurate picture of urban sustainability.

VQ: You also mentioned how cities are often more homogeneous because of sustainability practices, because of the environmental gentrification you were talking about earlier. Maybe we’re not only biased toward wealthy cities, but homogeneous cities as well?

DW: In a perfect world, all parts of our cities, our regions, and our countries would have equal access to environmental amenities. We’d have great parks everywhere, we’d have great changes everywhere. We don’t live in that world. We live in a world where these kinds of amenities are concentrated in specific areas, particularly in downtown neighborhoods. These are the ones where the most international travelers come through, and they have a lot of symbolic resonance.

The problem is that sustainability becomes another pathway along which displacement occurs, and therefore we get less diversity than we would have otherwise.

VQ: How should researchers be better at analyzing our cities and how should policymakers be better at enacting urban policy?

DW: The way I would think about this is to think about different actors and what constrains them. You can’t expect anybody in the city government to take too much time thinking about what’s happening outside the city. The business of a mayor is to run their city as best they can. We have to recognize that, so it would be unrealistic to say, “Look, the mayor of New York should be paying attention to what’s happening in China.” It would be nice, but that’s not going to happen. Policymakers, who are operating within relatively restricted jurisdictions, should focus more on the social equity side of sustainability issues.

For example, environmental gentrification is an issue that the New York City government, the San Francisco city government, and any other wealthy city government should have on its radar. It’s an issue that is occurring within municipal boundaries. Policymakers have been much too slow to recognize the environmental impacts that groups that we don’t think of as environmental actors are making. We think about housing movements that fight for good rent controls, for more affordable houses being constructed, for more public housing. These groups are actually making very serious environmental interventions. But they don’t use that language, so policymakers aren’t inclined to think of them as environmental groups.

We know one of the things that cities can do to really lessen the environmental impacts of city life is to build really good affordable housing. Policymakers certainly should be paying more attention to the social equity implications of sustainability policies—and also getting as many people around the table as possible to talk about environmental issues, including social groups who are fighting over issues like housing and transit. These are environmental issues, whether or not we use that language.

On the side of researchers, there are also the  international organizations and non-profits. These are actors who are a lot less constrained by the geography issue. Researchers absolutely should be making sure that they bust out of city boundaries when they’re studying and analyzing the impacts of environmental policy. We absolutely need to look at things on a regional scale. We know that things that happen downtown have knock-on effects that ripple through the entire suburban landscape as well.

International organizations, national governments, nonprofits, and other groups should be doing their best to connect policymakers across multiple boundaries. Even if the city governments can’t, the state and the national governments could be the ones to say, “Hey, you guys need to talk to each other.”

Municipalities rely on grants for a lot of their programs. Grants could be given preferentially for sustainability policies that are going to have some kind of regional analysis built in. In a nutshell, all the different actors should operate in the largest possible terms that they’re able to.

VQ: September is our cities issue and every year we rank cities according to their livability. We really struggled, as we do every year, with how to rank the important elements that really make a city “livable.” Have you gone about doing this? Ranking cities or at least analyzing cities according to best practices, according to a more regional framework, or carbon consumption or that kind of thing?

DW: The problem is that, and this is a pretty classic academic response, we just don’t have enough data to do this properly. If you wanted to just look at carbon accounting, which is such an important issue, there are only a few cities that have done proper consumption-based carbon counts. Until more cities have done that, comparing them is just not going to tell you that much.

The other problem is that you really do run into issues of boundaries and jurisdiction. If we’re comparing cities, we have to compare whole regions. You don’t just look at the city, because the city boundary is a historical accident. We look at the whole urban region that’s all functionally interconnected.

But the problem is that the way that these are defined really varies across place. Even just within the United States, the census bureau defines urban regions based on counties, but if you look at the southwest the counties are huge. But in the northeast they’re tiny. Even just within the U.S., where statistics are really good, it’s very hard to compare cities. If you look at it internationally, forget it. At the end of the day the problem is we don’t have the data to do a good job of comparing cities. Period.

That doesn’t stop us from comparing them, which means that it’s always going to be, whether we like it or not, subjective and partial. My job is not so much to do the rankings as it to say, “We need to get a lot better at how we measure what’s going on in cities if we want these rankings to have real meaning.”

VQ: You said there are only a couple of cities that have counted carbon according to consumption. Which are they?

DW: San Francisco’s done it. Seattle has. London has. Some researchers who aren’t even working directly for a city are looking at consumption carbon counting. There was one recently done in Shanghai.

I think we’re probably not far off from a lot more of these being done, because part of the issue has been the methodology. That problem’s more or less solved now. Now, it’s just a question of municipalities stepping up and saying, “Okay, we’ll start measuring our carbon this way.”

Another part of the problem is that some of the cities that have been quite progressive in terms of their climate policy probably stand to come out looking much worse, if they do a proper measurement. At the end of the day, the consumption-based accounting is going to reveal a lot more carbon associated with wealthy cities.

It’s a bit of a tough sell to say to policymakers because they may  look bad. Even so, San Francisco and Seattle, they’ve done this. It’s definitely not impossible.

VQ: It takes a self-reflective city.


VQ: It makes me think of Bjarke Ingels’ idea of “hedonistic sustainability.” This almost puts a critical eye on that; it’s almost like you’re saying, “Well, maybe on an individual level, that might be valid, but if you zoom out, you’ll look and see the side effects of this hedonism.”

DW: Ingels very correctly identified the fact that sustainability can be a very luxurious, pleasurable thing. That’s good. But the problem is that sustainability and environmental issues then become tied up in all the usual questions about inequality, about who has access to amenities and who doesn’t. At the end of the day we’re arguing that the environment is an amenity, and like other amenities, it’s being distributed in radically unequal ways. I don’t think he’s wrong, but if we believe what he’s saying, we should get a lot better at how the amenity of sustainability gets distributed among the people.

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