COPENHAGEN (AFP) – Police battled demonstrators outside the UN climate summit on Wednesday as leaders of developing nations let rip at wealthy counterparts, exposing the mighty obstacles facing a deal to tame global warming.

Police with dogs fired teargas and arrested around 260 marchers near the Bella Center, while inside the conference venue fears swelled that ministerial wrangling could wreck hopes for a deal. Related article: The political price of failure in Copenhagen.
Around 1,500 demonstrators tried to march on the closely guarded complex, where 194 nations are seeking to forge a strategy to head off the dangers from rising oceans, droughts, plagues and storms threatened by soaring temperatures.
Inside the conference centre, a man and a woman stormed on to the main stage after a speech by Senegal's President Abdoulaye Wade, repeatedly shouting “Climate justice now!” before being taken away by security guards.
Many delegates from developing countries applauded and away from the stage, world leaders arriving for Friday's grand summit of 120 chiefs, portrayed the negotiations in a sombre light.
British Prime Minister Gordon Brown acknowledged a deal would be “very difficult,” while his Australian counterpart Kevin Rudd said there was “no guarantee” of accord.
Friday's summit hopes to conclude a post-2012 strategy by setting down the outlines of an accord on curbing carbon emissions and craft a mechanism to provide billions of dollars for poorer countries in the firing line of climate change.
Scientists warn that many millions of people face going hungry, losing their homes and access to water within the next decade if nothing is done to stem the rise in greenhouse gas emissions.
But nine days of official and informal negotiations have failed to produce a breakthrough on any of the key issues.
In one of the first speeches by a head of state, Venezuelan President Hugo Chavez railed against what he called “the imperial dictatorship” of the West and said poorer nations would buck the diktats of the rich. Related article: China opposes 'carbon tariffs'.
“There's a group of countries who think they are better than U.S. in the South, in the Third World,” he said before taking a dig at U.S. counterpart Barack Obama for receiving the Nobel Peace Prize after announcing the dispatch of 30,000 more troops to Afghanistan.
Chavez said rich countries had rushed to spend heavily to save their banking system yet were Scrooge-like like when it came to averting a far greater peril.
“If the climate system was a bank, they would have already saved it,” he quipped.
Speaking on behalf of Africa, Ethiopian Prime Minister Meles Zenawi said the world's poorest continent would not agree a deal at any price.
“We are determined to make sure that in Copenhagen we will have an agreement that all of us, Africa included, are happy with or there will be no agreement for anyone,” said Meles.
Tiny Tuvalu, a Pacific archipelago of nine coral atolls which is one of the countries most at risk from rising sea levels, likened the state of negotiations to the Titanic.
“It's time... to launch the lifeboats, it's time to save this process,” its chief negotiator Ian Fry said.
Chinese chief negotiator Su Wei complained the process was “not transparent” and warned of “very grave consequences if we do not resolve this issue.”
With the conference moving towards its climax, Danish Prime Minister Lars Lokke Rasmussen took over as chairman, replacing Connie Hedegaard who will lead informal talks.
“People around the world are actually expecting something from us,” said Rasmussen, showing frustration at events.
European Union environment commissioner Stavros Dimas voiced concern.
“We are entering the last phase of the negotiations and we should stop the games,” he told AFP.
Some of the bitterest wrangling has been between the world's two biggest carbon emitters, China and the United States, which declared on Tuesday they would not shift on their emissions pledges, the thorniest problem of all.
Obama has offered to cut U.S. carbon emissions by 17 percent by 2020 over a 2005 benchmark, a figure that aligns with legislation put before the U.S. Congress.
It amounts to a reduction of around four percent compared with the more widely used reference year of 1990. The European Union has pledged to cut emissions by 20 percent on 1990 levels by 2020.
The Copenhagen summit has been mired with organizational problems with the number of people accredited outstripping capacity by around 30,000.
Thousands of activists from non-governmental organizations were forced to leave the venue on Wednesday to accommodate VIPs, fuelling anger among those who already feel their voices are not being heard.
Photo: Climate demonstrators march towards the Bella Centre where the UN climate summit is taking place on December 16, 2009 in Copenhagen, Denmark. (Getty Images photo) -