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Energy: Curbing urban greed

Nature volume 481, pages 142143 (12 January 2012) | Download Citation

An overview of resource-guzzling US cities has lessons for us all, finds David Orr.

The Very Hungry City: Urban Energy Efficiency and the Economic Fate of Cities


Yale University Press: 2012. 384 pp. $28, £25 9780300162318

Austin Troy concludes The Very Hungry City by writing: “Good cities are good places to live. But they take work.” In the United States, that is both the promise and the problem. With few exceptions, such as Washington DC, US cities grew by happenstance, contrivance and often by connivance. The same is increasingly true of megacities worldwide. Growth without planning — as Troy shows in his trek through conurbations from Los Angeles to Copenhagen to Masdar City in Abu Dhabi — has huge implications for energy use and the natural resources that support it.

Overbuilt Phoenix, Arizona, faces a dry future. Image: A. MACLEAN/GETTY

Troy, an environmental economist, gives us a sure-handed, cogent treatment of urban challenges, focusing on 'urban energy metabolism' — a city's pattern of energy use determined by its location, culture, history and size. Most US cities need massive energy inputs per capita compared with many of their European, Chinese or developing-world counterparts. The price they pay is a vulnerability to scarcity, rising costs and environmental decay. Troy traces energy use through water consumption, transport, construction, the heating and cooling of homes, and the creation of workable communities, and includes sidebars on energy choices from renewables, natural gas and coal to nuclear power, oil and biofuels.

He describes a drearily familiar pattern that has accelerated since the mid-twentieth century. With little planning or foresight, inner cities are forsaken for suburbs, from which people flee to yet more distant 'exurbs' — a pattern of urban greed that consumes land, infrastructure, people and energy. The United States is littered with extreme examples: on the one hand is Detroit, Michigan, a proud industrial city of around 2 million people in 1950 that is now reduced to a beleaguered population of 700,000 circled by affluent suburbs; on the other is glittering, overbuilt Phoenix, Arizona, facing a future of extreme heat and dessication.

Elsewhere, notably in the US Sun Belt, 'zombie' urban subdivisions built far from city centres drive up energy and resource use. Even urban success stories elsewhere, such as Stockholm, face the challenges of energy and resources that come with continued growth.

How did we get to this point? Americans have traditionally regarded cities as places where you make money fast and move on. The combination of greed and devil-take-the-hindmost economic theories led to the abandonment of whole sectors of urban economies when people found their mobile capital could earn them a bit more somewhere else. Racism also played a large part. Banks refused to invest in minority-dominated inner cities, resulting in segregated poverty and crime. And then there is the car, an indiscriminate wrecker of urban fabric, air quality and climate stability.

As a result of all this, the United States still does not have a coherent urban policy. That has cost the country dear — not least in terms of the human cost of wars fought over the oil needed to subsidize inefficient urban growth.

Underpriced and oversubsidized fossil fuels made energy cheap, but that era is stumbling to an end. Accelerating climate destabilization, peak oil extraction, water shortages and rapidly growing urban populations are looming global challenges. More than half the people in the world live in cities, and it is here that humanity's future will be decided — albeit in a global economy with a diminishing margin for waste and policy mistakes.

Yet we can curb the urban energy appetite. Troy covers a growing list of successes — stories of improved energy and resource efficiency, better technology, collective solutions and foresight. For example, semiconductor manufacturer Intel is pumping three-quarters of the water it uses in its New Mexico facility back into local aquifers. The city of Los Angeles is belatedly resuscitating its once-extensive urban light-rail system. Vermont has deployed a highly successful statewide energy-efficiency programme.

Policy tools such as location-efficient mortgages — which encourage people to buy houses in areas that have abundant public transport — can help to recalibrate economic incentives with energy and climate realities. Congestion-charge schemes such as that in London are reducing traffic in dense urban areas, and time-of-day charges for electricity cut energy use. Even the Empire State Building in New York has been refurbished to lower its energy use by 38%, hinting at potential changes for older buildings everywhere.

Energy-efficient developments are proving to be popular and economically viable. Denver, Colorado, for instance, has revitalized derelict properties in the lower downtown area. Portland in Oregon set up a growth boundary for the city in 1973, deflecting investment downtown with dramatic results. And creative urban designers such as Peter Calthorpe — a pioneer of community models that integrate principles such as environmental sustainability and mixed-use building — continue to push the boundaries. The keys to making smart development the default setting and not an anomaly are creative, long-term public policies and investment strategies that stress energy efficiency and the deployment of renewable energy.

We may even be seeing the start of a global urban renaissance in places such as Masdar City. Once finished, it will house 50,000 people and get all of its energy from sunlight and other renewable sources. But this does not mean abandoning existing urban settlements. Many older European cities are prosperous, attractive and increasingly sustainable because they have preserved a coherent core and developed a robust urban infrastructure for bikes and light-rail systems. In short, cities in many other countries are doing a great deal better than those in the United States.

There are two models of our urban future. One is a dystopian nightmare of crowded, decaying, violent cities. Troy presents the other: a vision of lean, efficient, human-scaled, sustainable cities fed by efficiency, better design and renewable energy.

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  1. David Orr is the Paul Sears Distinguished Professor of Environmental Studies at Oberlin College, Oberlin, Ohio 44074, USA.

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Correspondence to David Orr.

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