As two weeks of talks in Bonn drew to a close, the chair of a negotiating group, Margaret Mukahanana-Sangarwe, published her proposal for a new compromise text.
While it mentions all issues relevant to keeping Earth from overheating - from cutting greenhouse gases to financial aid and technology exchanges from rich to poor countries - it also leaves all the major sticking points unresolved.
Bolivian Ambassador Pablo Solon said the new text favors developed countries and incorporated too much of the so-called Copenhagen Accord, a political declaration brokered by President Barack Obama at the troubled U.N. conference in the Danish capital last December.
"This is not a basis for negotiations," he said. "We are in the middle of a very complicated situation."
While U.N. experts and other key players postponed official comments while the proposal was being analyzed, environmental groups 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.
It also remained unclear if the document would be accepted as an official negotiating text for further talks leading up to the U.N. climate summit in Cancun, Mexico, at the end of this year.
The text says, for example, that industrialized countries should aim to cut greenhouse gases 25 to 40 percent by 2020 - which scientists say is necessary to slow down 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 were also worried that references to the 1997 Kyoto Protocol - the international climate change agreement setting targets for industrialized countries to cut their emissions greenhouse gases - 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. U.N. officials say a comprehensive deal is unlikely even this year.
Scientists say the world needs to cut the growth of greenhouse gas emissions quickly to limit global warming to 2 degrees Celsius (3.6 degrees Fahrenheit) or less as compared to preindustrial times. Otherwise the world will have to face rising seas as well as severe droughts, flooding and heavy storms due to global warming.