But sceptics are using a flood of leaked e-mails from a British University -- dubbed "Climategate" -- to question the findings.

You can read the Copenhagen Diagnosis here, by 26 researchers worldwide.  It says a thaw of summer sea ice around the North Pole, for instance, has far outpaced projections in a report by the U.N.'s Intergovernmental Panel on Climate Change (IPCC) two years ago. They say world emissions must peak by 2020 to avoid the worst of climate change.

They say that sea levels could rise by perhaps a metre, at worst 2 -- a figure also mentioned recently by U.N. Secretary General Ban Ki-moon -- and far above scenarios in 2007 by the IPCC. More than 190 nations will meet in Copenhagen from Dec. 7-18 to try to agree a new pact to combat global warming.

But the leak of thousands of hacked documents from the University of East Anglia has added fuel to the debate because they include snide comments about climate sceptics and exchanges about how to present the data to make the global warming look convincing.

Phil Jones, head of the Climatic Research Unit at the university, is quoted today as saying that he "absolutely" stands by his findings and says the suggestion that there was a conspiracy to alter evidence was "complete rubbish".

I've had a several e-mails from people who doubt humans are to blame for global warming saying that "Climategate" indicates that the Copenhagen Diagnosis is a new example of alarmism. Will this be a new pattern before Copenhagen?

Experts say the leaks from the University don't affect conclusions by scientists who found in the 2007 IPCC report that it was more than 90 percent sure that human activities, led by burning fossil fuels, were to blame for warming over the past 50 years. Governments -- including the United States when President George W. Bush was in office -- also signed off on those findings.

But the U.S. Senate has not agreed carbon-capping legislation and the leaks are hardly a good argument to persuade waverers to join other industrialised nations in capping carbon emissions.

*by 2100! thanks for pointing out!

(Picture: Icebergs float in the calm waters of a fjord, south of Tasiilaq in eastern Greenland August 4, 2009. REUTERS/Bob Strong)

GPS markers usually pinpoint a spot on the earth's surface to help everything from map-making to navigation.

This one (left) spectacularly didn't.

In fact, it wandered hundreds of miles (km) this year on an iceberg, blown by winds or carried by ocean currents in huge pirouettes off the coast of Antarctica.

When glaciologist David Vaughan (above) of the British Antarctic Survey stuck the pole holding the GPS (global positioning system) tracking device into the Wilkins Ice Shelf in Antarctica in January, the ice felt solid as rock.

Stuart McDill of Reuters TV and I had landed with him in a small plane mounted with skis on a 40-km-long floating ice bridge which had been in place probably for thousands and thousands of years. But it was weakening and about to snap in what Vaughan said was a sign of global warming.

We didn't stay long.

The GPS marker was meant to transmit its position to satellites to help monitor movements in the ice shelf -- up to about 250 metres thick -- to measure the strains before it finally cracked up. The ice bridge shattered in April and collapsed into a swarm of icebergs.

But surprisingly, the GPS kept on going for months -- broadcasting its position as a lone metal spike that may have puzzled passing penguins or the odd whale. The diagram above shows where it began (near top right by Charcot Island and then southwest until its last transmission on Aug. 30. No one knows its fate - maybe the batteries gave out or its iceberg cracked up.

The GPS did far better than planned. Vaughan had been convinced that the GPS, set up for Michiel van den Broeke of Utrecht University and colleagues, was not going to work at all. After he set it up, it went "beep beep beep" to signal that it was OK but then fell silent.

We all thought it had failed; we didn't know that it was programmed to beep only briefly to show that it worked -- too many beeps would have drained the batteries.

(Picture: REUTERS/Alister Doyle, diagram: Roderik van de Wal, Utrecht University, Matthias Braun, Bonn University) 

So is there a risk -- if negotiators are not smart -- that the new U.N. accord to fight global warming will stall like the long-running Doha round on freeing world trade, launched in 2001?

India's Environment Minister Jairam Ramesh, for instance, said on Oct. 10 that negotiators should aim for a realistic agreement in Copenhagen from Dec. 7-18 that was not too ambitious. He said there was a risk of repeating the "mistake of the Doha round", saying that "the basic problem of the Doha round was 'all or nothing'."

And British Finance Minister Alistair Darling said on Oct. 21 that he wanted to ensure that the climate talks do not keep dragging on like the Doha round.

The WWF environmental group says there's a lack of leadership in the run-up to Copenhagen, with a rise in whispered suggestions that the talks might fail.

One week of formal climate negotiations remains before Copenhagen, in Barcelona from Nov. 2-6, after almost two years of meetings.

"The world doesn't want Copenhagen to come to mean another Doha," said Kim Carstensen, head of WWF's Global Climate Initiative.

Talks on the existing Kyoto Protocol for curbing emissions, agreed in Japan in December 1997 also often looked bleak in the run-up, especially after the U.S. Senate voted that year by 95-0 against some of the basic principles of an accord. 

WWF accused industrialised nations of trying to lower expectations for a deal "as they continue to dodge the hard decisions on slashing their emissions and funding the transition to a low carbon economy."

So will Copenhagen echo Doha?

((Picture: Top: Smoke rises out of a cement plant in Baokang, Hubei province September 12, 2009. REUTERS/Stringer. Right: A Qatari security policeman guards the WTO conference centre during the 2001 conference in Doha. REUTERS/Nayef Hashlamoun))

responsibletravel.com said it was dropping carbon offsets from its website, bucking an industry trend of recent years.

Ever more airlines and travel groups offer customers the option of paying a bit more to plant trees in Africa, for instance, or to help build a wind farm in India to soak up greenhouse gases equal to those emitted by their vacations.

"We believe that the travel industry's priority must be to reduce carbon emissions, rather than to offset," said Justin Francis, managing director of the British-based firm.

"Carbon offsets distract tourists from the need to reduce their emissions. They create a 'medieval pardon' for us to carry on behaving in the same way (or worse)," he said.

The company said: "In 2002 we were the first travel agent to offer carbon offsetting, in 2009 we believe we are one of the first to stop offering offsets to customers."

The firm said it agreed with environmental group Friends of the Earth that offsets were a "dangerous distraction".  "Ultimately we need to reduce our carbon emissions. We can do this by flying less -- travelling by train or taking holidays closer to home for example, and by making carbon reductions in other areas of our lifestyles too, alongside travel," it said.

Criticising travel -- rather than selling letting people buy indulgences for a high-carbon lifestyle -- sounds like shooting yourself in the foot if you are selling holidays.

Or is this a smart decision?

The prize will be handed over in Oslo on Dec. 10, the anniversary of the 1896 death of the award's founder Alfred Nobel, and the U.N. talks will run in Copenhagen from Dec. 7-18. It takes about an hour to fly between the two Scandinavian capitals.

And the Norwegian Nobel Committee heaped praise on Obama, including his climate policies, in its citation.

"Thanks to Obama's initiative, the USA is now playing a more constructive role in meeting the great climatic challenges the world is confronting," the secretive five-member committee said.

 Some Norwegian politicians said they hoped the award would stiffen Obama's resolve to push the U.S. Senate to pass early legislation to cut greenhouse gas emissions in the years to 2020.

Former U.S. President George W. Bush dropped efforts to get the Senate to ratify the U.N.'s Kyoto Protocol, a pact adopted by all other industrialised nations for curbing greenhouse gas emissions until 2012. Obama wants the United States to have a bigger role in a new global treaty to be agreed in Copenhagen.

Environmental group Greenpeace said Obama should visit Copenhagen.

"In accepting the award in Oslo on 10th December President Obama has an incredible opportunity, and responsibility, to then travel to the UN Copenhagen Climate Summit to help avert climate chaos and conflict," Greenpeace's International Executive Director Gerd Leipold said in a statement.

And Denmark's Climate Minister Connie Hedegaard also expressed hopes that Obama would come to Copenhagen: "It's hard to imagine that he will be receiving the Nobel Peace Prize in Oslo on Dec. 10th and then come empty-handed to Copenhagen a week later." 

And what a difference a week makes -- the award of one of the world's top accolades in Oslo is a stunning turnaround just a week after Obama went to Copenhagen and suffered a defeat by unsuccessfully lobbying for Chicago to get the 2016 Olympic Games.

But a problem is that the first week of the Copenhagen talks will be run only by senior government bureaucrats -- environment ministers from around the world are due to turn up only from Dec. 16 to decide on a new pact to succeed the Kyoto Protocol. 

So, to have the most impact on the negotiations, should Obama go for a few days' vacation skiing in Scandinavia after collecting the Nobel Prize before travelling to Copenhagen?

(Picture credits: top - U.S. President Barack Obama (R) and first lady Michelle Obama arrive for an event to look at the stars with local middle school students and astronomers from across the country on the South Lawn at the White House in Washington, October 7, 2009. REUTERS/Jim Young. Right: The Nobel Peace Prize medal awarded to South African Archbishop Desmond Tutu)

Or is it too early after environmental prizes in both 2004 and 2007?

The five-member Nobel panel likes to make topical awards to try to influence the world -- a prize announcement on Oct. 9 linked to climate change could hardly be better timed since 190 nations will meet in Copenhagen in December to agree a new pact for fighting global warming.

And the Nobel prize will be formally handed over at a ceremony in Oslo on Dec. 10 -- the anniversary of the death of founder Alfred Nobel -- giving any winner a global loudspeaker during the the Dec. 7-18 meeting in Copenhagen.

But any would-be green laureate has a big problem -- former U.S. Vice-President Al Gore and the U.N. Climate Panel shared the 2007 prize and Kenyan environmentalist Wangari Maathai won in 2004 for her campaign to plant trees across Africa.

Three prizes so fast might well be one too many.

Bookmakers don't rate green candidates very highly this year -- one has Chinese dissident Hu Jia at 5-1 followed by Zimbabwe's Prime Minister Morgan Tsvangirai at 11/2. Greenpeace is an outsider at 40/1.

And the environment is still a controversial new area for the committee -- some critics said that it had nothing to do with peace when Maathai won.

Geir Lundestad, the director of the Norwegian Nobel Institute, defends the green choices and says there's no rotation of themes for peace -- disarmament one year, human rights the next, etc.

"When the ice melts in the Arctic, new territorial issues arise. When the waters rise in Bangladesh, hundreds of thousands of people flee to India, creating difficulties. And when the desert spreads in the Sahara it leads to new difficult issues," he said.

"There will be many different roads to peace and there is no rotation (of themes), as there is no rotation as far as geography is concerned," he told Reuters.

Even if there is no green prize from a record field of 205 candidates in 2009, maybe concern about the environment could indirectly influence the choice in other ways?

Lundestad said several years ago that the committee should speak out sooner rather than later this century about the lack of democracy in China  -- so far it hasn't done so. But the committee might not want to irritate Beijing, for instance by awarding the prize a prize to a dissident, just when China is offering to do more to rein in its greenhouse gas emissions.

((Pictures - top: A large iceberg is seen on the edge of a morning fog over Frobisher Bay, Nunavut in the Canadian Arctic August 21, 2009. The picture was taken from a Canadian Forces Aurora patrol aircraft flying south of Iqaluit and taking part in military manoeuvers in the Canadian north. REUTERS/Andy Clark. Right: The Nobel Peace Prize medal awarded to South African Archbishop Desmond Tutu's Soweto in 1984, recovered a few days after thieves broke into his home in June 2007. REUTERS/Stringer))

British and American English speakers often differ about whether to pronounce it "Copen'hay'gen" or "Copen'haa'gen". And interviews for the Reuters Global Climate and Alternative Energy summit this week are bringing varieties in between.

But what do Danes reckon? I called up an expert:

"We'd normally say "Copen'hay'gen in English," said Ida Ebbensgaard," spokeswoman for Danish Environment Minister Connie Hedegaard who will host the Dec. 7-18 meeting.

Or maybe delegates from the 190 nations can try saying the word in Danish -- "København" (...pronounced something like "Sjobenhaavn").

  (Photo: Denmark's Little Mermaid statue)

The announcement by the U.S. Environmental Protection Administration that it has found chemical contaminants in domestic well water near natural gas-drilling rigs raises more questions about the safety of a method of gas extraction called hydraulic fracturing. For a story, click here.)

The EPA’s finding, based on tests in rural Pavillion, Wyoming, marks the first time the federal agency has tested water in response to growing complaints from around the U.S. that gas drilling is polluting groundwater with toxic substances.

Canadian energy giant EnCana, which operates almost 250 gas rigs in the area, notes that the industry is just one possible source of the contamination, a point echoed by the EPA itself, which has been at pains to point out that it has reached no conclusion about the source of the chemicals.

The agency will conduct more tests to determine how the substances got into 11 of 39 wells tested during March and May this year.

But the test results, first released to local residents on Aug. 11, are a boost to opponents of hydraulic fracturing or “fracking” who have been struggling to prove their case because the oil and gas industry doesn’t have to disclose what it puts in its drilling fluids, thanks to an exemption passed during the Bush administration to a federal clean water law.

Energy companies contend that the chemicals used in “fracking” -- which are forced deep underground along with water and sand -- are heavily diluted, encased in layers of steel and concrete, and injected so far below drinking-water aquifers that there’s no significant chance of an escape.

Congress, goaded by public disquiet about gas drilling, is considering a bill that would require drillers to disclose what they are putting in the ground, and remove the loophole that has allowed them to argue that publicizing the composition of drilling fluids would put them at a competitive disadvantage.

But it may be tough to resist pressure to maximize the flow of a clean-burning fuel that the Obama administration sees as key to U.S. energy policy.

Farmers are often portrayed as the villains, slashing and burning trees to clear land for crops and wrecking forests from the Amazon to Indonesia (...not to mention Europe, where people cleared most forests thousands of years ago).

But a report today by the World Agroforestry Centre indicates that farms aren't such enemies of trees as usually thought - it says tree canopies cover at least 10 percent of almost half the world's farmland.  That is a gigantic area the size of China, or Canada. (For a story, click here).

Ten percent doesn't sound much but one common definition of a "forest" by the U.N.s' Food and Agriculture Organisation is an area where tree canopies cover at least 10 percent. It excludes farmland or urban areas (-- otherwise your local supermarket car park might qualify if it's got a few trees dotted around the tarmac).

Farmers sometimes keep trees as a backup if their main crops fail -- with their deeper roots, trees producing fruit or nuts, for instance, can withstand droughts or floods better than many crops. Farmers also keep trees for uses such as a source of building materials, medicines or shade.

So trees are more common on farms than thought -- and a home to a wider variety of insects or animals than a swathe of grassland, maize or wheat. They may also be a bigger store of the greenhouse gas carbon dioxide than expected, with a role in limiting global warming.

So have farmers got too bad a rap for deforestation?

(Pictures: top: Cows graze under a solitary maple tree on a hill near the central Bohemian town of Votice 63 km (40 miles) south of Prague, July 18, 2009. REUTERS/Petr Josek. Centre left: Pedestrians walk over an empty parking lot in Beijing's central buisiness district August 20, 2007. REUTERS/Reinhard Krause. Bottom right: Cattle graze in a deforested jungle near Maraba, in Brazil's central state of Para May 3, 2009. Soon thousands of cows will be chewing pasture on the freshly cleared land in Brazil's Amazon state of Para, just a tiny part of Brazil's 200-million-strong commercial cattle herd, the world's biggest. REUTERS/Paulo Whitaker)

As an example, he says that works out as a lump 39 kms long, 10 wide and 1 km thick. Or I reckon it could be a blockbuster ice cube with sides 7.3 kms long -- that would smother most of  a large city such as Paris (top left -- you can see the Eiffel Tower in the middle).

David's numbers give an idea of the scale of the thaw under way -- seas have been rising at about 3 millimetres a year in recent years in a trend that almost all climate scientists blame on global warming caused by human activities. That's equivalent to a rate of 30 cms a century.

And it's also a lot faster than a rise of 1.8 mm a year from the 1960s, according to the U.N. Climate Panel. The thaw is one of the spurs to action under plans for a new U.N. treaty to fight global warming due to be agreed in Copenhagen in December.

Some scientists reckon seas could rise by one metre this century. Most of the rise projected by 2100, however, is likely because water expands as it gets warmer, rather than because of a thaw of glaciers or of ice sheets smothering Greenland or Antarctica.

One bit of good news on the ice front is that it looks as if sea ice in the Arctic will not shrink to a new record low this summer, after 2007 marked the smallest since satellite records began in the 1970s (and probably a lot longer than that).

Ice shrinks to its annual low in September before freezing out again: so far the ice is still far bigger than in 2007 at the same time although it is also far smaller than the 1979-2000 average, according to the U.S. National Snow and Ice Data Center. And ice floating on the sea doesn't really contribute to raising sea levels -- it's effectively part of the water already.

(Picture: undated satellite image of the Eiffel Tower and the surrounding area in Paris, France. REUTERS/DigitalGlobe TZ)