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Deep Green: Are Cities Sustainable?

Background - November 16, 2009
A reporter from Dubai phoned last week and asked, "Can Dubai become a sustainable city?" and specifically, "Could the tourism industry be sustainable?" In the age of global warming and declining fossil fuels, the entire airline industry is probably not sustainable. Dubai, of course, is not even remotely sustainable.

Rex Weyler

Dubai is a city built with oil cash, but the global economic recession brought construction schemes to a sudden halt. Many entrepreneurs fled the city, abandoning some 3,000 cars, found with keys in the ignition and maxed-out credit cards in the glove compartments.

Between 2002-2008, the United Arab Emirates (UAE) and its partners invested $600 billion US dollars in Dubai, creating the world's tallest building and largest shopping mall, man-made islands, and an indoor ski hill. Dubai has a beach 'designed' by Versace with chilled sand. Meanwhile, sections of the city have no sewage system, so sewage is collected by truck convoys and driven into the desert, where it seeps back through the sand - and reappears on the Versace beaches.

On the artificial islands, 20 million dollar villa properties sit empty, without power or sewer systems. Developers will eventually have to protect the faux-island real estate from the rising seas caused by global warming. So, no, Dubai is not sustainable, but neither is any other city.

The sustainable cities are small, modest, usually poor, semi-rural centres, closely linked to local food and energy sources. One of the most ecological western consumer cities is Lingköping, Sweden. In the 1980s, Lingköping's seven political parties agreed to pursue a non-partisan 'Environment Path'. They replaced oil and coal heat with electricity from municipal waste and reduced city CO2 emissions by 40 per cent. The city offers free recycling, public transportation that runs on electricity and waste-biogas, bicycle paths, and reduced taxes due to income from the public waste-energy utility.

Even so, Dubai, Lingköping and all cities rely on goods, services, energy, and resources from around the world, delivered by fuel-guzzling transport. We hear a lot these days about 'sustainable cities', but let's look at the reality.

Cities in history

Hunting and gathering is a sustainable lifestyle. We know this because all animals live this way, and humans lived this way for several million years. Early human fire-making hunters caused local extinctions and disturbed natural habitats, but the real problems with sustainability began with urban concentration.

Four thousand years ago, Sumerian cities on the Euphrates river plains required intensive agriculture and irrigation, causing erosion and salt accumulation. Sumerian texts describe barren soils and 'earth turned white'. The communities migrated north along the river seeking new fertile soils, leaving abandoned cities to disappear under the sand.

By 500 BC deforestation and soil erosion had left most cities gasping for food and resources. In 460 BC, as the population of Athens swelled with war refugees, filth piled up, and a plague (probably typhus) killed over a third of the population. Cities everywhere began to experience similar plagues, and the human population growth rate began to decline for the first time in history.

Forty thousand years earlier, in Cro-Magnon communities, human population growth remained extremely slow, a few thousandths-of-one per cent each year. But this rate climbed steadily, and by 500 BC the growth rate reached 100 times higher, over a tenth of one per cent - about 0.13% -a year. However, cities became population drains, and by about 200 AD, the population rate had dropped below zero, and total human population decreased for the first time in history.

This growth rate did not recover to the 500 BC level for two thousand years, until about 1750 AD. During those two millennia, cities - centres of filth, disease, toxic smoke, and conflict - killed off more people than they produced. Lewis Mumford explains in The City in History that small, rural Mediaeval towns remained relatively clean and functional, but between 1200 and 1500 AD, large cities became centres of death and human population dropped incessantly. Meanwhile, burgeoning empires required ever more resources from distant lands.

The forests of Europe had been devastated by 1550, which provoked the use of coal fuel and an industrial boom in Europe. Burning coal increased urban air pollution, causing more death and disease. In 1661, John Evelyn described sections of London as 'suburbs of Hell'.

Smoke inhalation, typhus and cholera killed urban citizens everywhere. In the 20th century, with the additional toxic effect of leaded gasoline exhaust, thousands perished from 'killer fog' in London, and US cities including Pittsburgh, Chicago and St. Louis. Four thousand died in London in December 1952 and hundreds died in Los Angeles in 1954. But modern industrial empires, like their ancient predecessors, still sought more resources from greater distances.

The biophysical city

Dr. William Rees at the University of British Columbia, who developed the 'ecological footprint' analysis, points out that most cities require the environmental services from a land base 300 to 1000 times the city area. Rees points out that a city is a 'biophysical entity' that includes the complex of land, water, atmosphere, resources, and waste sinks required to support the human population.

Rich consumer cities of Europe and North America require the most ecological space, but all modern cities carry an ecological debt to nature. I live in Vancouver, Canada, which prides itself as being a fairly 'green' city with bike paths and urban gardens, but even so, Vancouver requires a global biophysical area about 390 times the city itself.

In the study Ecosystem Appropriation by Cities published by the Royal Swedish Academy of Sciences, Carl Folke and colleagues estimate that the 29 largest Baltic cities - including Copenhagen, Stockholm, Oslo and Helsinki - appropriate for their resource consumption and waste an area of forest, agricultural, marine, and wetland ecosystems over 560 times the area of the cities themselves. New York requires a total eco-footprint almost 1000 times the city's geographic area. Tokyo requires twice the entire domestic bio-capacity of Japan.

The Folke study shows that the 744 largest cities worldwide require more CO2 sequestration than the entire world's forests could provide. "If the goal is sustainable human settlements," write the authors, "the increasingly limited capacity of ecosystems to sustain urban areas has to be explicitly accounted for in city planning and development."

Meanwhile, human activity continues to degrade the ecosystems that keep cities alive. Each year, we loose about 13 million hectares of forests and 6 million hectares of arable land, while adding some 75 million new humans - the combined populations of Mexico City, Mumbai, Seoul and Sao Paulo.

"These data show that, in material terms, 'sustainable city' is an oxymoron," says Rees. "Modern cities are entropic black holes sweeping up the productivity of a vastly larger and increasingly global resource hinterland and spewing an equivalent quantity of waste back into it."

Reduce consumption

Dubai may be one of the more obvious examples of reckless urban consumption, but it is not alone. Most modern cities remain vulnerable to distant food supplies, degraded cropland, declining fossil fuel resources and climate change impact, including rising seas and human migrations.

"To act consistently with our best science may well require a planned economic contraction," says Rees. He believes the wealthy nations "should plan to reduce their ecological footprints by almost 80 per cent" to consume only an equitable share of global biocapacity.

Peter Victor, in the book Managing without Growth, believes this is possible; that human society can dump its untenable economic ideas about growing consumption. The only way out of our dilemma - ecosystem 'overshoot' - is to consume less stuff. There is no magic technology that will allow us to continue consuming at current rates, much less at growing rates. But Victor, Rees and others believe we can live higher quality lives with less consumption, particularly if we turn urban density into an advantage.

Here are some things we need to do to make cities less destructive and more sustainable. Many modest, small rural communities already do these things, which is why they are already more sustainable:

  • Reduce per capita demand for land and water resources (consume less stuff).
  • Reduce fossil energy consumption, and all energy consumption.
  • Preserve farmland and grow local food for local consumption.
  • Share: create co-housing, public transport, and food cooperatives.
  • Be satisfied with second hand clothes and furniture, and make simplicity, modesty, justice, and ecology your fashion statement.
  • Improve urban infrastructure, water, sewage systems, and recycling.
  • Gain efficiencies with neighbourhood scale technologies, such as heat pumps, electricity co-generation, district heating/cooling, using industrial waste heat systems.
  • Create low throughput and closed loop industries, in which waste energy is captured and waste materials become feedstocks for other uses.
  • Eliminate planned obsolescence in product design; build things that last.

We have to rethink cities as complete ecosystems that fully account for their consumption. "The aggregate effect," says Rees, "would be global sustainability."

 - RexWeyler

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