Critics slam new climate change proposal in Bonn

Still, the United Nations said progress was made at the two-week meeting in Bonn.

"This all in all is a big step forward making much more possible in Cancun," said U.N. climate chief Yvo de Boer, referring to the next major climate summit in Mexico at the end of the year.

In Bonn, negotiators from 185 countries tried to revive efforts for a global treaty to fight climate change after the disappointing U.N. summit in Copenhagen in December.

Summing up the talks, the chair of a negotiating group, Margaret Mukahanana-Sangarwe, presented a compromise text on all major issues of a climate treaty which was meant to bridge some of the differences between rich and poor nations and to become the basis for further negotiations.

However, delegates from countries including the United States, China, India, Brazil and Pakistan rejected the text in a floor debate.

Bolivian Ambassador Pablo Solon told reporters the document favors developed countries and incorporates too much of the so-called Copenhagen Accord, a political declaration brokered by President Barack Obama in the Danish capital.

"This is not a basis for negotiations," Solon said. "We are in the middle of a very complicated situation."

Environmental groups also were not impressed.

"This text has moved very little," Wendel Trio of Greenpeace told reporters.

On content, we don't see the progress we need," said Antje von Broock of Friends of the Earth.

Nonetheless, outgoing U.N. climate chief de Boer said at his last news conference that the two-week session had advanced chances for a climate deal. "This session has made important progress," said de Boer, who will step down July 1.

He specifically mentioned nearing compromise on technical issues concerning climate funding, adaptation, technology transfers, and deforestation. However, he also said more ambition is needed in actually cutting greenhouse gas emissions.

"The two-degree-world is in danger," de Boer said, referring to the goal to limit global warming to 2 degrees Celsius (3.6 degrees Fahrenheit) as compared to preindustrial times.

The new text mentions industrialized countries should aim to cut greenhouse gases 25 to 40 percent by 2020 - which scientists say is necessary to slow global warming. But the document does not set a year when that comparison should start. Scientists say the base line should be 1990, while the United States has argued for 2005.

Solon said poorer nations also were worried that references to the 1997 Kyoto Protocol - the international climate change agreement setting emission targets for industrialized countries - were eliminated.

Intense negotiations on the new climate treaty have been going on for three years.

In 2007, a U.N. conference in Bali decided the deal should be finalized in 2009, but the effort failed in Copenhagen. De Boer has said a comprehensive deal is unlikely even this year, but the "architecture" for the treaty could be agreed on.

Scientists say the world needs to stop growth of greenhouse gas emissions quickly to prevent dramatic consequences of global warming, such as rising seas, severe droughts, flooding and heavy storms