Much of today's environmental impacts originate in cities

The world has seen a dramatic shift to urban living. In 1900, only 10 per cent of the global population were urban dwellers; now it's more than 50 per cent. More than 95 per cent of the net increase in global population will be in cities in the developing world

Cities are both drivers of and responders to environmental changes in rapidly developing countries like China and India. Unprecedented growth in urban population over the past century has occurred in less than 3 per cent of the global terrestrial surface. But their impact has been global, with 78 per cent of carbon emissions, 60 per cent of residential water use and 76 per cent of wood used for industrial purposes