Edge of sustainability: why Rio+20 mustn't ignore people on city fringe

By 2030, 60% of the global population will live in towns and cities, particularly in Africa and Asia where the urban population is set to double in the next two decades. (..) Alongside rapid urban expansion comes the growth of peri-urban areas, bringing flows of people, commodities, capital, natural resources, waste and pollution, and conflicts over land and water. (..) Rio+20 must ensure the poor don't lose out from rapid urbanisation.