The UN's climate change summit is in chaos.

Leaders of some the world's richest countries are scrambling today to put a positive spin on the UN's climate change summit.

World leaders emerged with a climate agreement last night which they claimed was a “first step” in tackling global warming – but which campaigners criticised as “a toothless declaration” which would fail to avert catastrophe.

UK officials claimed to be “hopeful” that a climate deal could be reached tonight, but an agreement announced between the US and major developing economies was condemned by environmentalists as “a toothless declaration” which would not tackle global warming.

President Barack Obama tonight announced a “meaningful and unprecedented breakthrough” on a global effort to curb climate change.

A senior official in US President Barack Obama’s administration said tonight that America, China, India and South Africa have reached a “meaningful agreement” on climate change at the Copenhagen summit.

US President Barack Obama raced from one impromptu meeting to another and made an animated plea for compromise at the climate change summit in Copenhagen today, making plain his frustration over the difficulty of pushing world leaders to settle on a plan to combat global warming.

There is still “a lot of work to be done” to secure any international deal on climate change, Britain's Gordon Brown said tonight as talks between world leaders in Copenhagen remained deadlocked.

World leaders are edging towards a climate change deal in Copenhagen - but a new draft agreement has allegedly dropped a deadline of 2010 for reaching a legally binding treaty.

The US has offered no new targets to cut greenhouse gas emissions, despite being the world's second biggest carbon emitter.

US President Barack Obama joins world leaders in Copenhagen today in a final push to secure a new deal on climate change amid growing optimism that an agreement can be reached.

Climate change delegates were today privately admitting hope was running out for a comprehensive deal today, even as world leaders began flooding into Copenhagen.

Taoiseach Brian Cowen will travel to Copenhagen today for the final two days of the UN Climate Change Summit.

British Prime Minister Gordon Brown and UN Secretary General Ban Ki-Moon tonight raised hopes that a deal could be done to provide long-term finance for developing countries to fight global warming.

Baton-wielding riot police clashed with hundreds of demonstrators who tried to storm the Copenhagen climate conference today.

More than 100 climate activists were arrested trying to break into the Copenhagen conference today.

A showdown between the world’s two largest polluters loomed over the Copenhagen climate talks talks today as China accused the United States and other rich nations of backtracking on a deal to fight global warming.

The Pope today called for urgent action to protect the environment, saying that climate change and natural catastrophes threaten basic human rights such as life, food and health.

China, the world’s biggest polluter, today accused developed countries of backtracking on their duty to fight climate change.

The atmosphere both inside and outside the UN climate conference has become more tense after talks were suspended for most of yesterday's session, and police detained up to 200 protesters on Copenhagen's streets.

Protesters have scaled Sydney Opera House and unfurled a banner on the iconic building urging world leaders to strike a treaty to combat climate change.

Developing countries today agreed to resume climate change negotiations in Copenhagen after a half-day suspension.

UN climate talks were thrown into chaos today as developing countries blocked negotiations and demanded that rich nations increase their efforts for reducing greenhouse gas emissions.

The international climate talks stepped up a gear today hoping to reach a deal with only five days left.

Environment Minister John Gormley was today among ministers from 48 countries arriving

Cuba’s President Raul Castro declared the global climate summit in Copenhagen a failure from the start and urged left-wing Latin American leaders to devise their own plan on how to cope with climate change.