In 1992, William McDonough represented architects and the American Institute of Architects at the Rio Earth Summit, at which Agenda 21 and the Rio Declaration were signed. At that time, McDonough and Michael Braungart wrote the Hannover Principles (published in book form the next year), to be presented at the Hannover World Expo in 2000.
Learn about Agenda 21 here.
Learn about the Rio Declarationhere.
Learn about the Rio+20 Earth Summit here.
From the Earth Summit site:
The world is facing a mounting crisis. In recent years we have experienced a combination of a global financial crisis, a food crisis, volatile oil prices, accelerating ecosystem degradation and an increasing number of climate-induced extreme weather events. These multiple and inter-related crises call into question the ability of a growing human population to live peacefully and sustainably on this planet, and demand the urgent attention governments and citizens around the world. Earth Summit 2012 will be the fourth Summit of its kind and represents another milestone in ongoing international efforts to accelerate progress towards achieving sustainable development globally.