Green belts are among the oldest and most widely used policies for controlling sprawl. During the twentieth century they have been employed to contain the explosive growth of cities as varied as Tokyo, Seoul and Melbourne with a variety of results. Increasingly, policy-makers, researchers and even environmentalists have pointed to the failings of a green belt approach, favouring more pragmatic or more linear green space concepts such as eco-belts and greenways. As yet, no research has attempted to gather these experiences together, to guide future reforms and consider whether a green belt is a useful policy for the twenty-first century.By bringing together and comparing the experiences of green belt reform across Europe, North America, Asia, Australia and New Zealand, this book adds to the understanding of how a green belt can be effected in theory and how practitioners have adapted or reformed the green belt in practice. A team of leading researchers and practitioners examine how contemporary debates, on sustainability, ecology and political reform intersect with the implementation of green belts globally and the discipline of planning. The book provides a series of case studies to enable researchers and policy-makers alike to reach conclusions on the usefulness of green belts, the challenges that exist in implementing them and the impact of their alternatives.