A crucial UN climate summit opened here today amid calls for "early action" to combat the threat and with the hope that emission reductions promised by key countries had put the world closer to a global warming control pact.
"This is our chance. If we miss it, it could take years before we got a new and better one. If we ever do," conference president Connie Hedegaard said adding, key to an agreement is finding a way to channel public and private funds to poor countries to help them fight the effects of climate change.
At the beginning of the meet, a short film was screened showing children of the future facing an apocalypse if world leaders failed to act today.
"There will be hundreds of millions of refugees," R K Pachauri, the head of the UN Intergovernmental Panel on Climate Change, said in the clip.
Addressing the delegates from 192 countries, Pachauri stressed that years of dedicated work by the scientific community showed that "the evidence is now overwhelming that the world would benefit greatly from early action and that delay would only lead to costs in economic and human terms that would become progressively high".
He also slammed the so-called 'climategate', or the theft of some emails from experts at a British university, which were seized on by climate sceptics as evidence that scientists distorted data to dramatise the threat of global warming.
Danish Prime Minister Lars Loekke Rasmussen told the opening ceremony that the world is looking to the conference to safeguard the future of the mankind.
"For the next two weeks, Copenhagen will be Hopenhagen. By the end, we must be able to deliver back to the world what was granted us here today: hope for a better future."
Along with 15,000 delegates, more than 100 world leaders including US President Barack Obama, Prime Minister Manmohan Singh and Chinese premier Wen Jiabao will attend the 12-day summit for which security has been beefed up.
Yvo de Boer, UNFCCC executive secretary, said there was unprecedented political momentum to clinch an ambitious deal but countries needed to negotiate harder.
"Time is up," de Boer said. "Over the next two weeks nations have to deliver".
The first week of the conference will focus on the text of a draft treaty. Major decisions may await arrival of the environment ministers next week and the heads of state in the final days of the meet, which ends on December 18.
As the first commitment period for greenhouse gas emissions reductions, regulated by the Kyoto Protocol, would expire in 2012, the international community would endeavour to map out a plan for binding emissions cuts for the second commitment period from 2012 to 2020 at Copenhagen.
Delegates must craft a blueprint for tackling manmade "greenhouse" gases and put together a funding mechanism for helping poor nations fight climate change.
