Planned ‘greenbelts’ that buttress cities were essential to the Victorian Garden City movement and later to New Deal community experiments. They give urban areas form and territorial control, while showing where nature and agriculture end and human-designed settlement begins. This project considers the diffusion of 19th and 20th century greenbelts, using examples from the United Kingdom, United States, and Australia. These projects, with hints of utopian thinking, were also immersed in Malthusian ideas of selecting an ‘ideal’ population both in number and composition. The project analyzes how greenbelts were a preserve away from increasingly congested cities, but the original intention and form of the communities were subverted by mass suburbanization. Today, greenbelts have once again been hailed as a local level means to fight climate change but given their history they could potentially function as a tool of exclusion and a way for wealthier cities to hoard environmental resources.