Keeping Track of our Changing Environment: From Rio to Rio+20 (1992-2012)
http://www.unep.org/GEO/pdfs/Keeping_Track.pdf
Commemorates the 20th anniversary of the Rio Earth Summit conference to address the state of the environment and sustainable development. Reviews developments at the 1992 and 2002 conferences, progress made over the years, and previews goals and objectives for the 2012 conference. From the United Nations Development Programme