Urban agriculture can result in environmental, social and economic benefits. There are three primary environmental benefits from organic urban agricul­ture – preserving biodiversity, tackling waste and reducing the amount of energy used to produce and distribute food.

Modern industrial farming techniques in the countryside have had a devastating effect on bio­diversity. The combination of fertiliser and pesticide use with habitat destruction means that urban envi­ronments are now often more species-rich in fauna and flora than their rural counterparts (Nicholson – Lord, 1987).

Added to this has been the effect of a few large supermarket chains dominating food retailing. For example the United Nations Food and Agriculture Organisation cite Belgium, France and the United Kingdom as ‘extreme examples’ where only 10 per cent of retail units account for more than 80 per cent

of food distribution (Food and Agriculture Organisation, 2002). Supermarkets’ reliance on economies of scale and repeatable quality standards inevitably favours larger suppliers and the use of chemicals in preference to environmentally benign agricultural methods. In contrast, urban food pro­duction, particularly current forms such as urban farms and community gardens, tends to be charac­terised by the use of organic methods and the local sale of produce.

Urban agriculture also offers the potential to use organic waste for composting, thereby reducing the need for land-fill (see Chapter 12).

Food is being transported further than ever before, often by air between countries on opposite sides of the world, whilst local crop varieties are replaced by a few commercial types popular with supermarkets (Cook and Rodgers, 1996). This pattern of growing ‘food miles’ is far from sustainable, its by-product being increasing air pollution, notably of major greenhouse gases such as carbon dioxide, increas­ing road congestion and noise, and increasing stress. Urban food production supplying local outlets offers an alternative to this pattern (see Chapter 5).

The consequences of this are evident in the reduced numbers of varieties of particular fruit and vegeta­bles available in most supermarkets; reactions against this include the Italian ‘Slow food movement’ which promotes the use of fresh local produce and the associated culture of convivial eating.

At the same time, many people in poorer urban parts of European cities are living in areas that are effec­tively becoming retail deserts (see Chapter 6). Such factors underline the unsustainability of current trends in food retailing and production. Despite this, the whole issue of food security and food supply with its attendant environmental, social, economic and health knock-on effects is one which very few munici­pal or national authorities have addressed.