green cities

With half the world's population now living (in many cases, just surviving) in urban areas, this would be a good time to consider the role of the natural environment in cities.

And I mean really consider it, not just plant a few trees down the boulevard. (Not that I'm knocking urban forests, but even street trees need careful planning.) Big cities have big impacts. Perhaps it's a good thing that in Africa, smaller cities are growing faster than big ones, because with bigger cities struggling to cope with the influx, smaller ones often have better housing standards and living conditions.

This [growth of smaller cities] doesn't have to be a bad thing. Urbanisation can make it easier for governments to provide schooling and healthcare for its citizens, the report points out, and sound city planning can help reduce a country's overall environmental degradation. While many smaller cities struggle with scant financial resources, they also tend to have greater flexibility in planning, space and decisionmaking.

The UN's recent State of World Population 2007 predicts that "for the foreseeable future, the smaller cities will predominate".

Big or small, "sound city planning" is not something that comes naturally. Some have even suggested that it's not planners or engineers or architects who design cities. It's bankers. And bankers don't give two hoots about sustainability, so somebody else has got to put things right. Here are some thoughts.

Cities need fewer cars. Even if vehicles were all nonpolluting, a recent study pointed out that in Indiana (USA) parking spaces outnumber drivers 3-to-1. Parking, roads, driveways - all that infrastructure devoted to to motorised vehicles is not just unnecessary, it harms communities and adds to the urban heat island.

Urban heat is usually fought with the brute force of airconditioning, which is an intensive user of electricity (generating carbon emissions) and doesn't actually reduce heat, it just moves it outside. Far better to use trees and other vegetation to reduce the buildup of heat in the first place.

Better building design can even further reduce the need to artificially cool (and heat, and illuminate) buildings. Put your architect on notice: if he doesn't reduce your building's energy needs, fire him. It's not that difficult.

Green roofs are slowly gaining ground, and for good reason. Not only do they reduce solar heat gain, they reduce the building's heat loss in cold winters, can provide a green space for people to use, can be used to grow food, increase biodiversity, attract birds and butterflies, clean the air and reduce stormwater runoff.

Reducing or delaying the flow of rainwater into storm drains can help reduce the amount of money spent on drains, and reduce flooding during heavy storms. There are lots of ways to do this, but some municipal engineers don't take it seriously. They should, because they will not only save money, but also provide green spaces on the ground for social and sports activities and all the benefits offered by green roofs.

Cities need more walkers, cyclists, joggers, runners, amblers, rope skippers, sitters, hopscotch players, perambulators, rollerbladers, hikers, strollers and aimless wanderers with nothing better to do than enjoy life.

Comments

[Kristina Richardson]

Everyone can make a difference! If you are passionate about stopping global warming and the environment you should check out this website http://www.nvisioncfl.com . Changing to CFLs is a great way for individual people to really make a difference! You should also check out this site http://www.youtube.com/user/helpourworld for more ideas on how to help our world!

[Rory]

Sure, Kristina, every bit counts. Incandescent bulbs should be a thing of the past. But how about getting nvision to move on to LED lighting?

[Henri Laurie]

"And bankers don't give two hoots about sustainability, so somebody else has got to put things right. Here are some thoughts."

Perhaps we should recognise that sustainable growth is simply impossible---the two terms are mutually exclusive. To be sustainalble, periods of growth have to be matched by periods of decline.

I have come to believe that human beings will see the truth of this only when catastrophe forces us.

In other words, we WILL HAVE a huge population crunch somewhere in the future (I have no idea whether 5 years, 500 years or 50000 years). If we get through that with enough knowledge preserved then perhaps we will swop our current model of growth without sustainability with a model of sustainability without growth.

But that really is the choice. The sooner we accept it, the less the severe the population crunch need be.