Urban agriculture, the growing of food and non-food plants, trees and livestock in urban and peri-urban areas, was largely abandoned last century, but it is enjoying a revival in the past few decades.16 In Moscow, for example, urban agricultural activity increased three-fold between 1970 and 1990. In Dar es Salaam it nearly quadrupled from 1968 to 1988, and in Romania it more than tripled (up 333%) from 1990 to 1996. In Argentina home gardening association members grew from 50,000 in 1990 to 550,000 in 1994. In metropolitan areas in the United States, food production increased from 30% in 1988 to 40% in 1996, and from 1994-1996 the number of farmer's markets selling locally-grown produce increased 40%. In great Bangkok 60% of the land is under cultivation. Urban agriculture facilitates the closing of the loop to food security. The demand for food by consumers and water and nutrients by producers reconnects resources and wastes in a safe, non-polluting and economic fashion.