Green belt

A green belt or greenbelt is a policy, and land-use zone designation used in land-use planning to retain areas of largely undeveloped, wild, or agricultural land surrounding or neighboring urban areas. Similar concepts are greenways or green wedges, which have a linear character and may run through an urban area instead of around it. In essence, a green belt is an invisible line designating a border around a certain area, preventing development of the area and allowing wildlife to return and be established.

The more general term in the United States is green space or greenspace, which may be a very small area such as a park.

In those countries which have them, the stated objectives of green belt policy are to:

The green belt has many benefits for people:

The effectiveness of green belts differs depending on location and country. They can often be eroded by urban rural fringe uses and sometimes, development 'jumps' over the green belt area, resulting in the creation of "satellite towns" which, although separated from the city by the green belt, function more like suburbs than independent communities.

In the 7th century, Muhammad established a green belt around Medina. He did this by prohibiting any further removal of trees in a 12-mile-long strip around the city. In 1580 Elizabeth I of England banned new buildings in a 3-mile wide belt around the City of London in an attempt to stop the spread of plague. However, this was not widely enforced and it was possible to buy dispensations which reduced the effectiveness of the proclamation.

In modern times, the term emerged from continental Europe where broad boulevards were increasingly used to separate new development from the centers of historic towns; most notably the Ringstraße in Vienna. Green belt policy was then pioneered in the United Kingdom confronted with ongoing rural flight. The term itself was first used in relation to the growth of London by Octavia Hill in 1875. Various proposals were put forward from 1890 onwards but the first to garner widespread support was put forward by the London Society in its "Development Plan of Greater London" 1919. Alongside the CPRE they lobbied for a continuous belt (of up to two miles wide) to prevent urban sprawl, beyond which new development could occur.

There are fourteen green belt areas in the UK covering 16,716 km² or 12.4% of England, and 164 km² of Scotland; for a detailed discussion of these, see Green belt (UK). Other notable examples are the Ottawa Greenbelt and Golden Horseshoe Greenbelt in Ontario, Canada. Ottawa's 20,350-hectare (78.6 sq mi) instance is managed by the National Capital Commission (NCC).