If architecture is 'design for living', one of its greatest challenges is how to live with the masses of waste we excrete. Four pioneers in green sanitation design outline solutions to a dilemma too often shunted down the pan.
Urban campaigner and architect Arif Hasan has been central to a sanitary revolution, transforming Orangi, Karachi, from informal settlement to thriving community. Using his technical know-how, residents built a sewage system, sparking vast social change. Now chair of Pakistan's urbanization task force, he discusses incorporating sustainable design into poor cities.
International trade is the underlying cause of 30% of threatened animal species extinctions, according to a modelling analysis of the impact of global supply chains and consumption patterns on biodiversity.