Peter Madden, chief executive of Forum for the Future, writes a monthly column for Gristmill on sustainability in the U.K. and Europe.

Every year more and more people live in cities. Globally, we became a majority urban world for the first time last year, while here in the U.K., nine out of 10 of us live in towns and cities.

Cities are clearly important for sustainability. Although the romantic green notion of us all living on small holdings with a goat, a vineyard, and a vegetable patch is seductive, the future is much more likely to be dominated by megacities such as Mumbai, Shanghai, and Sao Paulo. We will have to learn to make such cities liveable and sustainable.

Concentrating people in urban centers does make it easier to provide some social and environmental services. But the big cities also have a huge environmental footprint. London, for example, has an ecological footprint 293 times its geographical area.

Cities are also important as centres of dynamism. They are where social, cultural, and economic innovation and change happens. Yet despite the undoubted importance of cities, most of the environment movement in the U.K. is still predominantly rural- and wildlife-oriented. They defend and protect stuff most ordinary people will never see. The greens haven’t been very good at doing green cities.

Our big cities, on the other hand, haven’t done a very good job of being sustainable either. Lots of our leading cities are making green claims. Manchester is determined to become “the Greenest City in Britain by 2010,” Leicester calls itself “the environment city,” Bristol wants to become a “Green Capital,” and London is aiming for nothing less than the status of “most sustainable city in the world.” But behind such claims there is very little objective measurement of what it means to be sustainable. We certainly don’t have anywhere that really stands out as an example of overall good practice.

So, we at Forum for the Future decided to get stuck into the debate on sustainable urbanism. We researched and published a table ranking our 20 biggest cities.

Our first question was what to measure. Some researchers have looked at ecological footprint, with no sense of what the city is actually like for its citizens. Others focused on quality of life, but ignored the wider environmental impact. So we used thirteen indicators grouped in three sets of criteria:

  • Environmental Impact of the city — the impact of the city on the wider environment in terms of resource use and pollution;
  • Quality of Life for residents — what the city is like to live in for all its citizens; and
  • Future Proofing — how well the city is preparing itself for a sustainable future. We added the last category specifically to recognize those cities that are starting from a difficult base in terms of their social or industrial legacy, but are moving in the right direction.

So, who won? For those of you who know the U.K., Brighton and Hove came on top, with Edinburgh second. Liverpool, unfortunately was at the bottom. (The full report is available here [PDF].)

There were a couple of clear messages from the study. Unsurprisingly, the wealthier cities tend to do better in the index. These cities may have more resources to devote to sustainability issues. And affluence might explain why voters here are more concerned about green issues: the average vote for the Green Party in the 2005 General Election was 7 percent across the top three cities, and only 1 percent across the bottom three.

Service-based cities also do well. Again, this is not surprising. The top cities tend to be ones which are building their future in the service industries, and do not have to deal with such a difficult industrial legacy. Of these service industries, tourism would appear to be particularly influential. Both Brighton (a seaside resort) and Edinburgh earn a lot of their income from tourism, and it makes sense therefore for them to invest in a high-quality physical and green environment.

I think that the strongest message was that, overall, our cities still have a long way to go on the journey to sustainability. For example, while we can congratulate Brighton and Hove on coming first, it still has a very high environmental footprint in terms of its impact across the wider world.

We will be running this index every year as part of a new program of work on green cities. We hope that it will make our cities better places to live, with a lower overall impact on the environment. We also hope it will encourage some healthy competition amongst our big cities to see who is greenest.

In some ways, the United States is ahead of us on the green cities agenda. This is partly to do with the fact that you have more power devolved down to the state and city level than we do. It may also be because under the Bush administration, cities got on and did things for themselves. I was in San Francisco recently, and was very impressed with what they are doing on recycling, public transportation, and green buildings.

I suspect, however, that your cities would score less well on their overall environmental footprint. But I may be wrong. If any of you can point to strong examples of sustainable urbanism, we would love to hear about them.