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CHARLOTTE WESTNEY
A noise map of London could help city planners to plot roads and buildings, scientists and policy-makers meeting at London's sustainability summit heard earlier this year.
Proposed developments can be fed into a computer model to see how they might alter their acoustic environment. Jenny Stocker and her colleagues of Cambridge Environmental Research Consultants (CERC) have built the model as a pilot; a £30-million (US$47-million) noise map of Britain is now planned.
The pilot is based simply on traffic-flow recordings and sound samples from a variety of locations. The country-wide model is likely to incorporate details of the interplay between buildings, trees, road width and surface, wind speed and direction, and noise from trains and airports.
"The aim is to look at the bad areas and see what can be done to improve them" without dispersing the noise to other areas, says Stocker. The model gives long-term averages of the noise levels that particular streets can expect, but it may not highlight occasional hot-spots of high noise, she warns. For these, regular measurements on the ground will be needed.
Stocker's model is a prime example of the kind of work that was discussed at London's Environment And Future (LEAF), a post-Johannesburg gathering of researchers, legislators and activists bent on ensuring that one of the world's largest cities contributes to a greener, more humane future for the planet.
City limits
"The problems that affect London affect many other cities in the world" but each city has individual troubles based on its economy, climate and surrounding areas, says conference chairman Julian Hunt, a climate modeller at University College London.
"The best [local] science is exactly what we need if we are to produce solutions to the world's pressing environmental problems."
Central to improving sustainability is measuring it. So also up for discussion is SPeAR, the Sustainable Project Appraisal Routine. This computer tool "illustrates complex information in a easily understandable way", says developer Lorna Walker of UK-based consultancy Arup Environmental.
SPeAR allows project stakeholders to visualize urban quality as a shape based on indicators of environment, social, economic and natural resources, such as access to green spaces and transport links to places of employment. "If you design good quality urban areas, they get looked after better," Walker says.
So far SPeAR has been used on small-scale developments, such as the refurbishment of the Jaguar factory in Halewood, near Liverpool, UK. Here it helped policy-makers to balance the project's low environmental and natural-resource scores against the positive impacts of the company letting its employees work on community projects while the factory was being refurbished.
Arup is currently developing 'corporate SPeAR' to assess companies, and 'city SPeAR' to give whole cities a sustainable shape. By using the same indicators in each case, SPeAR can compare sustainability before and after policy implementations. SPeAR could even rank different cities, although Walker admits that this could cause "huge arguments".
Bigger picture
But there can be problems globally when you only look locally, warns Tim Brown of the National Society for Clean Air and Environmental Protection, based in Brighton, UK. There can be problems globally when you only look locally for Clean Air
The confusing number of new technologies for cars - fuel cells, hydrogen and natural gas - is a case in point, he says.
Hydrogen is great locally because the only emission is water. But currently there are not enough renewable energy sources to make the hydrogen, so most of it would have to come from natural gas. This is bad globally as it produces carbon dioxide. Bio-fuels from plants also sound great but involve changes in land use and biodiversity.
LEAF delegates also discussed initiatives such as low-emission zones. This is an idea that London's local authorities are considering, allowing only 'clean' vehicles into certain areas, as a way to meet EU air-quality objectives for 2005.
© Nature News Service / Macmillan Magazines Ltd 2003
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