Big U.N. environmental summit opens in Rio

RIO DE JANEIRO — Leaders from around the globe gathered Wednesday to open three days of talks at the United Nations conference on sustainable development, where a sober, unambitious mood prevailed as negotiators produced what critics called a watered-down document that makes few advances on protecting the environment.

Negotiators worked for months to hammer out a document that many hoped would lay out clear goals on how nations could promote sustainable development — making economic advances without eating up the globe's resources.

But with time running out, contentious issues like technology transfers from rich to poor nations and new financing for developing countries were set aside. Diplomats agreed on what all call a mere beginning, a step toward a roadmap on how to embrace sustainable development at the conference dubbed "Rio+20" — coming two decades after the landmark 1992 Earth Summit put sustainable development on the globe's agenda.

U.N. Secretary General Bank Ki-moon acknowledged the world has made little progress on environmental issues since the first Rio meeting in 1992, but said leaders are working to reverse that at the Rio+20 summit.