The Volvo Environment Prize for 2004 was awarded to two outstanding urban development experts – David Satterthwaite and Jaime Lerner – each working on a different theme, and to a team of two exceptional scientists collaborating on a third theme – Luisa Molina and Mario Molina. Their work on these three closely linked urbanization themes has provided models for defining, understanding and addressing the rapidly growing and increasingly complex problems of the urban environment in developing countries.