It is possible to make cities more environmentally friendly, as a number of local initiatives demonstrate. The German city of Freiburg, traditionally a supporter of green measures, typifies a more ecological approach to city living: 13,000 of its residents live in sustainable districts, the best known being Vauban, created on the site of a former military base. The development is characterized, among other things, by low energy consumption; it relies on solar power and has car-free zones designed to promote travel on foot, by bicycle, or by public transport. Other examples are found in Curitiba, in Brazil, and Malmö, in Sweden, where the emphasis is on recycling, rain-water collection, and the development of green spaces—including rooftops—and genuinely mixed communities.
Buildings play an important role in the energy stakes: they are responsible for approximately 40% of Europe’s energy consumption and a percentage of greenhouse gas emissions. Most of these can be avoided: well-designed buildings consume so little energy that they can rely entirely on renewable energy sources—a phenomenon known as “passive” housing.
Today, a great many cities are taking steps to tackle climate change and promote sustainable development. They have grouped together around a number of initiatives such as the C40 Climate Leadership Group (C40 for short), an association of forty of the world’s largest cities committed to tackling global warming, and the International Council for Local Environmental Initiatives (ICLEI).
Nevertheless, comprehensive initiatives are isolated cases and are conceived on a modest scale. Cost is not generally the determining factor: governments frequently offer subsidies and, in any case, the longer-term savings rapidly compensate for the initial outlay. The main problem is that urban development is a slow process. It is easier to create a sustainable district from nothing than to convert existing homes and an existing urban space. This is why the most ambitious projects—and those that get the most media coverage—are the current new developments such as Dongtan, in China, and Masdar, Abu Dhabi.