All aspects of urban life — whether the sprawling North American cities, the megacities of the global south or even the typical buildings within them — depend on enormous resource consumption. In 2000 the global population was four times greater than in 1900 and used 16 times the resources. Every year the amount of fossil fuels burnt took a million years to produce. Half the world’s population now live in cities, covering two per cent of the Earth’s surface but responsible for three quarters of the resources consumed. How contemporary cities function is a major cause of climate change, but as the bulk are in coastal areas they will also be directly affected by the consequences of sea level rise. Urban citizens use four times the energy that rural dwellers consume, so as the proportion of the world’s population living in cities reaches and exceeds 50 per cent the problem will increase. Coupled with the rising cost of energy, that makes redesigning cities essential.
Diagrammatically, cities could move from linear consumers of resources and producers of waste, to a circular metabolic model which recycles its own waste. In practical terms, fuel cell buses and trams offer new opportunities for transport systems; the Bedzed development offers a model for low energy housing, and at a citywide level, 20 per cent of Copenhagen’s electricity comes from offshore wind farms. The key to redesigning existing cities and designing new ones lies in a combination of political initiative and technological innovation. Germany, where 160,000 people work in renewable energy industries, promotes photo-voltaic technology by buying electricity generated by cells on a domestic roof for four times the price of conventional power – which also has the advantage of involving individuals in effective action.
Only such a combination of political initiative and technological innovation will transform the way cities are designed and operate, and what happens in the rapidly urbanising and industrialising China is crucial. Despite its reputation, pointed out Girardet, there are positive examples such as Dongtan outside Shanghai on which he is a consultant with Arup’s as urban designers. As the world’s first ‘eco-city’ it shows how it might be possible to spread the ecological footprint around the city rather than across the globe, and by introducing urban agriculture, focusing on local loops of production, consumption and recycling.