1 Los Angeles is an unlikely city. Built over a major seismic fault, on the edge of one of the world's most inhospitable deserts, the city has developed like the extension of a Hollywood movie set, a sprawling urban fantasy which many people feel should not really exist. Scientists have estimated that the land and water in the area could naturally support 200,000 people, not the 15 million that live there.
2 Since the 1880s, Los Angeles has been transformed from a sleepy cattle town with a population of 4,000, to a seething metropolis that now accounts for nearly one per cent of global greenhouse emissions. It is the car culture par excellence, with nine million cars contributing to the ubiquitous smog and air pollution and 40 per cent of the population suffering from respiratory problems due to vehicle emissions. Surprisingly, LA is now becoming the forum for some of the most progressive environmental thought in the USA.
3 The city is full of contradictions. Often regarded as the apotheosis of consumerism and material extravagance, it is seen as the essence of anti-nature. Paradoxically, people often move to Los Angeles because of nature; attracted by its climate, the snow-capped mountains, the ocean and the beaches. The movie industry came here because of the clarity of the light, the 270 days of sunshine per year and the diversity of location close by.
4 The fantasy has always depended on one fundamental resource - water. No metropolis on the planet has looked farther afield for its supply than LA has, and the fact that there are "no more rivers to bring to the desert" is a cause of much concern. The natural water table was exhausted after four decades in the 1890s. In 1913, when the controversial Los Angeles Aqueduct was first opened, diverting water over 350 kilometres from Owens Valley, chief engineer William Mulholland proclaimed that it would supply Hollywood's lawns and swimming pools for ever.
5 Within ten years, the