(AP) -- A leaked Danish document at the U.N. climate conference provoked angry criticism Tuesday from developing countries who feared it would shift more of the burden to curb greenhouse gases on poorer countries.
Negotiators, meanwhile, displayed charts of data that said the current decade is on track to be the hottest on record for planet Earth.
At the heart of Tuesday's clash - stemming from draft texts attributed to Denmark and China - is the determination by the more impoverished states to bear a lesser burden than wealthy, more industrialized countries in the effort to slow global warming.
Diplomats from developing countries and climate activists also complained the Danish hosts had pre-empted the negotiations with their draft proposal, prepared before the two-week conference began.
"The behind-the-scenes negotiation tactics under the Danish presidency have been focusing on pleasing the rich and powerful countries rather than serving the majority of states who are demanding a fair and ambitious solution," said Kim Carstensen, head of the climate initiative for the environmental group WWF.
The Danish draft proposal circulating at the 192-nation conference chips away at the wall between what developed and developing nations can be expected to do to reduce emissions of greenhouse gases. The Danish proposal would allow rich countries to cut fewer emissions while poorer nations would face tougher limits on greenhouse gases and more conditions on money available to adapt.
A sketchy counterproposal attributed to China would extend the 1997 Kyoto Protocol, which required 37 industrial nations to reduce emissions of carbon dioxide and other gases blamed for global warming by an average 5 percent by 2012, compared with 1990 levels.
The Chinese text would incorporate specific new, deeper targets for the industrialized world for a further five to eight years. Developing countries, on the other hand, including China, would be covered by a separate agreement that envisions their taking actions to control emissions, but not in the same legally binding way. No targets would be specified for them.
Poorer nations believe the two-track approach would best preserve the principle of "common but differentiated responsibilities" recognized by the Kyoto Protocol.
Such draft ideas are usual grist early in such long, difficult international talks. These two proposals were not yet even recorded as official conference documents.
"It has no validity," key European Union negotiator Artur Runge-Metzger said, speaking specifically of the Danish proposal. "It's only a piece of paper. The only texts that have validity here are those which people negotiated."
Earlier Tuesday, the U.N.'s weather agency boosted the sense of urgency surrounding the conference with data showing this decade is on track to be the hottest since records began in 1850, with 2009 the fifth-warmest year ever. The second warmest decade was the 1990s.
Only the United States and Canada experienced cooler conditions than average, the World Meteorological Organization said, though Alaska had the second-warmest July on record. In central Africa and southern Asia, this will probably be the warmest year, but overall, 2009 will "be about the fifth-warmest year on record," said Michel Jarraud, secretary-general of the Swiss-based agency.
The last few decades are the warmest period in at least 400 years and probably 1,000 years, based on evidence from tree rings, retreating glaciers and other scientific methods to track climate before record-keeping, according to a 2006 report by the U.S. National Academy of Sciences.
Although temperatures have fluctuated, the causes were natural. The difference now is that they are being driven up by human activity, that modern civilization has many more coastal cities and needs to feed far more people, and that scientists believe humans can head off such dangerous warming.
Without a global deal stopping climate change, the planet's average temperatures will rise by more than 2 degrees Celsius (3.6 degrees F) "well before the end of the century," Jarraud said.
"What we want is to provide the best possible data for negotiators," said Jarraud, who called the WMO data evidence "this is indeed globally the warmest period for more than 2,000 years."
The current decade has been marked by dramatic effects of warming.
In 2007-2009, the summer melt reduced the Arctic Ocean ice cap to its smallest extent ever recorded. In the 2007-2009 International Polar Year, researchers found that Antarctica is warming more than previously believed. Almost all glaciers worldwide are retreating.
Destructive species such as jellyfish and bark-eating beetles are moving northward out of normal ranges, and seas expanding from warmth and glacier melt are encroaching on low-lying island states.
Rajendra Pachauri, chairman of the Intergovernmental Panel on Climate Change, and his colleagues defended climate research amid an uproar over a cache of e-mails stolen from a British university that global warming skeptics say show scientists conspired to hide evidence that doesn't fit their theories.
Panel members noted Tuesday that their authoritative reports, representing the work of some 2,500 international climate experts, included specific papers referenced in the e-mails, such as research into tree rings in Siberia that were discussed at length and had accompanying figures.
"Our processes are so robust, and the manner in which we function is so inclusive, that there is absolutely no question" about the integrity of research, Pachauri said. "They were clearly private communications. And if they express a level of passion all of us are guilty of at times, I think we should leave it well enough alone."
He said the IPCC has begun looking into the matter, but stopped short of launching a full investigation. "From what we've done so far, on a preliminary basis, we are completely satisfied that the IPCC procedures have not in any way excluded any material that's been peer-reviewed."
Carbon dioxide concentrations are expected to peak next year at a record high above 390 parts per million, up from 315 ppm when the first such measurements were taken a half-century ago.
"We are really on the higher end, at the pessimistic part of these ranges," Jarraud said. "So if nothing is done, we are going for much more than 2 degrees."
Swiss climatologist Thomas Stocker of the University of Bern noted that carbon dioxide levels are "higher than ever in the last 800,000 years," based on comparisons with ancient pockets of carbon dioxide trapped in polar ice core samples.
He said the C02 atmospheric concentrations have risen at a rate at least 10 times faster than ever before seen in paleoclimatic history.
The WMO also noted an extreme heat wave in India in May and a heat wave in northern China in June. It said parts of China experienced their warmest year on record, and that Australia so far has had its third-warmest year. Extremely warm weather was also more frequent and intense in southern South America.
According to the U.S. space agency NASA, the other warmest years since 1850 have been 2005, 1998, 2007 and 2006. NASA says the differences in readings among these years are so small as to be statistically insignificant.
The U.N. agency reported that the global combined sea surface and land surface temperature for the January-October 2009 period is estimated at 0.44 degrees C (0.79 degrees F) above the 1961-1990 annual average of 14.00 degrees C (57.2 degrees F), with a margin of error of plus or minus 0.11 degrees C. Final data will be released early in 2010.
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