Clinton Speaking at Rio+20 Summit U.S. Secretary of State Hillary Clinton has arrived in Brazil where she'll join leaders from 192 other nations at a big United Nations environmental conference. Clinton is scheduled to deliver remarks focusing on renewable energy and outlining the U.S. stance on sustainable development. The Rio+20 conference ends Friday after three days of high-level talks among delegations. A final document that was finished by negotiators just hours before the summit began is expected to be approved. Activists decry it as an unambitious statement making few advances on environmental protections beyond what was agreed upon at the original 1992 Earth Summit held in Rio. However, delegates roundly say that getting any agreement is a success, given the lack of appetite to tackle environment issues amid a global economic crisis.