Written version of my August 10 talk to the English for Graduate Studies Programs for Fulbright Scholars, through the English Language Institute at Syracuse University.

What does climate change have to do with the shape of the city? Climate change is one of the defining challenges of this era – perhaps the defining challenge – and as such, it’s a good bet that it will touch or is touching every aspect of life. That includes how we live in cities, and what kinds of environments cities create for people. Since that’s my area of focus as a researcher, this post examines that aspect of climate change. Climate change is so mammoth in its impact that from a single parcel of land, that occupied by the Syracuse Center of Excellence, we can see a number of landscape elements that are important to consider.
How people use land, including transportation, density, adn what happens to “used” land, is fundamental to understanding the drivers of climate change in the US, and why they are resistant to change. So if you’re interested in in climate change and why it’s happening and what to do about it, you should be interested in cities. Even if you live elsewhere, you should be interested in US cities with regard to climate change. We’re a disproportionate producer of greenhouse gases (GHG, but we’re also a leader in how cities are shaped and run. For good or ill, other people who are involved in the shaping and running of cities in other parts of the world look at American cities as models, much in the way that American cities were largely modeled upon European cities. 

Most of the world’s population lives in urban areas. Some of you may have heard about this: fairly recently we hit this milestone of global urbanization, where more than half of the world population lives in urban areas. This percentage is predicted to continue to rise to two-thirds of the world’s population by 2050. So in that way you could say cities are our future – all of our futures. Nearly 90% of that predicted increase of urbanized people is predicted to be in Asia and Africa, most especially India, China, and Nigeria. In the US we urbanized a long time ago, back in the 1920s. Currently US cities are home to just under 63% of the US population, but our cities comprise only 3.5% of our land area. Thus a key part of dealing with climate change is to handle how people live in cities. 

Photo: Looking west from the Center of Excellence

If we look westward from the Center of Excellence, we see a massive elevated highway. This is Interstate 81, which bisects Syracuse from north to south. Since 81 was built after the city was already established, it was built over a number of neighborhoods, displacing people, their homes, and their businesses. Syracuse right now is in the midst of a debate about the future of this highway, since it has reached the end of its designed life span. 

Interstate 81 exemplifies two key characteristics of American cities: the organization of the city around the private car, and sprawl. “Sprawl” here means that American cities tend not to have a defined clearly visible boundary between the city and the countryside or rural areas outside the city. Instead it’s a diffused boundary, as lower density development spills into the countryside and takes up a lot of land. These characteristics are intertwined with transportation. Transportation, it turns out, is also incredibly important to climate change. Transportation accounts for about one-quarter of greenhouse gas emissions both in the US and globally. This is a lot, but it’s even more when you consider that in the US it’s the number two source of greenhouse gas emissions after electricity generation, so it’s not just that it’s a huge chunk – it’s the second largest one. Here in Syracuse it’s actually even more of our total energy consumption, about 36%, so it’s more than one-third of Syracuse’s total energy consumption. Globally, there there there is predicted growth in the amount of greenhouse gas emissions due to transportation, mostly due to rapid growth in car use, especially in developing urbanizing countries like China. So transportation is key to climate change strategies. Here in the US, we lead the world in urban passenger transportation carbon dioxide emissions. Our carbon dioxide emissions due to transportation are actually projected to fall by 2050 in part due to redensification, or the trend of people moving back into city cores.

In 2013, President Obama put forward a climate action plan, with the basic proposal of reducing greenhouse gas emissions 26 – 28% below 2005 Levels by 2020. Compare those numbers: 26-28% to 25%, and you’ll see that transportation could account for almost the entire reduction on its own. So if we all stay right where we are, and no goods or products move from place to place – that is, if all transportation ceases – we’ve got the necessary reduction solved! Since we obviously can’t do that, we need to do transportation better. How do we do this? It’s simple: we drive less. Or we drive using clean fuels that don’t create GHG emissions. 

So what’s the problem? Let’s look again at Interstate 81. This is part of the American interstate highway system, which was constructed after World War II. It is a national system, including all 50 states (even Hawaii!) and all major cities. The situation Syracuse has of the elevated freeway going right through the center of the city, displacing neighborhoods and bisecting the city, is common. The original rationale for the interstate highway system was to aid national defense, modeled on Germany’s Autobahn (but with speed limits). However the impact that it has really was to promote suburbanization, which is building at the outside of of cities. The flip side of that is disinvestment in urban areas, like what you see around you in Syracuse. So the interstate highways moved people and money out of the cities and into the surrounding area. These consequences were in part unintentional and in part intentional consequences, because there were also a number of federal and state policies that favored suburban development for decades. These policies, with the interstate highways, set up a common dynamic where people with the economic power to choose live in the suburbs but work in city centers. Transportation between those two areas is therefore key to that way of life. The same dynamic has also created a number of challenges for urban areas in terms of being pleasant and attractive places to live. 

Interstate highways like 81 also work against more sustainable transportation directly. Elevated highways form a physical and psychological barrier to ground-level transportation in all forms. Imagine yourself walking down the street. From here, you can walk straight to downtown Syracuse. It’s about a mile, or 1.6 kilometers, an easy walk, flat, with a sidewalk the whole way. It’s easy to find your way to downtown, but people do not walk and do not ride bicycles because they don’t want to ride or walk under 81. You can see it’s forbidding. There’s no physical barrier here where we are looking, but it’s inhospitable. That has to do with the way that we as humans perceive environments around us, with what we prefer and what we don’t prefer. These perceptions make this feel dangerous to us, even if it’s not. Interstates like 81 also work against sustainable transportation by lowering property values around them. Simply put, people would rather live, work, recreate, and invest in properties that are not right next to the structure. It’s ugly. The traffic is really loud. There’s also issues with air pollution from all those cars, which leads to health problems like asthma and environmental lead (from the bad old days when gasoline included lead). 

As you can see, there’s quite a list of problems with this interstate and creating sustainable transportation. We know the sustainable transportation is very important to fighting climate change, so why not just get rid of the interstate? We don’t, because we already have the ring of suburbs around Syracuse, and all those people living in the suburbs and working in the city.  If you eliminate the interstate, how do you get from the suburbs to the city core? This highlights an important point about land development and land use patterns: they have a lot of inertia once established, because it costs so much to change the physical landscape and it’s a lot of work. Our next stop looks at that process of changing the landscape and how some kinds of construction are better than others with regard to climate change.

Photo: Looking south from the Center of Excellence

This construction site is what’s referred to as infill construction or brownfield redevelopment. “Infill” simply means that you are filling in an empty space within existing development. “Brownfield” means that there was a building on this site before. It’s often assumed to mean that the site is contaminated, although that’s not necessarily the case. Brownfields also include sites that are indeed contaminated, including with frightening things like dioxin. 

In any case, brownfield redevelopment like this is more sustainable than the alternative, which is building outside city areas. Why is it more sustainable? There’s less need for transportation, and remember, transportation is about a quarter of greenhouse gas emissions. If you live and work in buildings that are adjacent to each other, you just walk next door and there’s no greenhouse gas emissions. There’s also less need for new infrastructure, which is not as obvious. Infrastructure includes things like utilities and roads. When you build outside a city, you need to extend utilities – natural gas, electricity, water, sewerage – to the new development. You have to have a road to get there. In contrast, if you build on a site like this one, all those utilities are already here. Clearly the road is already here. You save all  that concrete, all that pipe, all that wire and cable and conduit. All of that has an ecological footprint – it’s all manufactured somewhere, so using less of it is more sustainable. Infill or brownfield redevelopment also preserves more land outside cities for natural areas, which can sequester carbon or mitigate some impacts of climate change like urban heat island. Brownfield redevelopment may also be more sustainable because it frequently involves buildings and site work that are more compact, using fewer resources. 

Despite all this, much construction in the US is the opposite of infill/brownfield redevelopment: greenfield development. Greenfield development means building on new land, kind of a ridiculous idea, because of course there is no “new” land. All land was used for something else before. In this case, it’s usually agricultural land or natural vegetation like forests. Greenfield development is seen as far easier, cheaper, and often more desirable than building on lots within the city. It tends to be more predictable, and unpredictable delays in construction are costly. Urban sites tend to have surprise environmental issues, when you dig into the soil and discover it is contaminated with something. There can also be delays when historical artifacts are uncovered, since construction has to halt while the artifacts are evaluated for historic significance. There’s also the more basic requirement of the need to work around and preserve existing structures, in contrast to building in an open field. On this site, there’s several valuable elements immediately adjacent to the construction: the wall of the Center of Excellence, the pavement around it, the trees along the street, even the street itself.

Because greenfield development is more popular, there are a number of federal and state grants and various incentives to redevelop brownfields. However they tend to focus on very large brownfield sites like old factories, landfills, or shipyards, and omit small sites like gas stations and dry cleaners. This site adjacent to CoE actually included an old gas station. Finally there is a consumer preference in the US for suburban or exurban housing. People in the business of developing land are aware of those preferences and they cater to them. We tend to think that new is always better, perhaps due to some bias in American culture toward seeing ourselves as breaking new ground and taming the wilderness. Our final stop on our walk around the CoE site looks at what happens to sites like this when they’re not redeveloped.

Photo: Looking north from the Center of Excellence

Looking at this view is somewhat tricky, because the element I want to discuss here is actually what’s not there: the land just across the street. People who study cities refer to this as vacant or underused land. This is one of the outcomes of what we talked about previously, including transportation, lack of investment in urban areas, and the difficulty of infill or brownfield redevelopment. Sites like the one across the street are not really used for anything. They tend to sit like this for a long time. These same dynamics also produce abandoned buildings, and abandoned buildings tend to become sites like this in our litigious society. It’s far easier for people to hurt themselves in an abandoned building then it is on a vacant site. People also tend to tear down buildings because they see it as as being cleared for a new use or to be more attractive to new investors. It makes “used” urban land a little bit more like that greenfield. If you look carefully, you’ll see that the vacant parcel across the street has a bit of asphalt on it, and that asphalt has some yellow stripes. If you look at an aerial photo of the site, you can see that those stripes are parking spaces. Underused urban parcels often are nominally used as parking lots, even if no one parks there. There’s some possibility of income from parking in urban areas. More than anything, however, this parking lot is merely a placeholder. It’s what this land will be until it becomes something else.

Vacant and underused land like this site indicate that infill development isn’t happening. They also increase the perception of urban neighborhoods as undesirable, dangerous places, full of contaminated land and other health hazards. If this was a valuable parcel, wouldn’t someone be living on it, or build a business on it, or turn it into a park? Regardless of the facts, the perception of parcels like this one can be quite negative, and in turn they influence the perception of the entire urban neighborhood. People on foot or on a bike may be reluctant to pass vacant lots like this one, especially at night, so they also act to suppress more sustainable modes of transportation.

In these three views from one parcel of land, we’ve seen a number of major factors in why land use in the US is a driver of climate change. We’ve also seen some reasons why our use of land resists change to more sustainable practices. Climate change is such a gigantic challenge that it’s sometimes difficult to grasp – it is, after all, *global* warming. It helps to realize that some important aspects of it are not exotic or huge in scale – that they are actually just across the street.

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Facts and sources:

  • U.S. Cities are Home to 62.7 Percent of the U.S. Population, but Comprise Just 3.5 Percent of Land Area. Source 
  • 54% of global population lives in urban areas; predicted to rise to 66% by 2050. Source
  • Nearly 90% of predicted increase in Asia and Africa, most especially India, China and Nigeria.  Source
  • More about “shrinking” postindustrial cities: The Shrinking Cities project
  • Transportation, driven by rapid growth in car use, has been the fastest growing source of CO2 in the world; US leads the world in urban passenger transportation CO2 emissions, and predicted decline due to re-densification. Source
  • Transportation is second-largest sources of greenhouse gas emissions in US, at about 25%. Source
  • Transportation produces roughly 23 percent of the global CO2 emissions from fuel combustion; increase in car use in developing countries means major growth. Source
  • Syracuse: transportation is 36% of total energy consumption. Source
  • US government policy’s history of promoting suburban growth over urban investment, including interstate highway system and redlining – excellent source for further reading is this classic (a book!): Jackson, K. T. (1985). The Crabgrass Frontier: The Suburbanization of the United States. New York, NY, Oxford University Press.​
  • Infill vs. greenfield land development and climate change: Basic information, with links to many, many more in-depth sources here.