A landmark conference on tackling climate change opened in Copenhagen on Monday to warnings of apocalyptic danger for mankind if world leaders failed to seize the moment. The impact on humanity of man-made drought, flood, storms and rising seas were spelt out at the start of the 12-day meeting, which will climax with a summit attended by more than 110 heads of state or government. Danish Prime Minister Lars Loekke Rasmussen warned the world was looking to Copenhagen to safeguard the generations of tomorrow. '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,' he said. Opening ceremonies began with a short sci-fi film featuring children of the future facing a nightmare apocalypse of tempests and desert landscapes if world leaders failed to act today. 'Please help save the world,' said a terrified little girl at the end of the film. The negotiation marathon gathers members of the UN Framework Convention on Climate Change (UNFCCC), the fruit of the 1992 Rio summit. Its rollcall of 192 nations was joined this year by Iraq and Somalia, the conference heard. Delegates must craft a blueprint for tackling manmade 'greenhouse' gases blamed for trapping solar heat and disrupting Earth's fragile climate system. They must also put together a funding mechanism able to channel hundreds of billions of dollars to poor nations most exposed to climate change. If all goes well, world leaders on December 18 will agree a political deal that sets down the course of action, including a roster of national pledges. Further negotiations are expected to take place in 2010 to fill in the details. A legally-binding treaty would take effect from the end of 2012. Analysts, though, point to the gulf between demands from developing countries and the willingness of rich countries to dig both into their pockets and into their carbon emissions. Connie Hedegaard, a Danish minister elected to chair the talks, said political will would 'never be stronger.' 'This is our chance. If we miss it, it could take years before we get a new and better one -- if ever.' US President Barack Obama is hoping to push through a new deal after the United States -- the world's biggest economy -- rejected the Kyoto Protocol under his predecessor, George W. Bush. Leading US negotiator Jonathan Pershing was cautious, saying Copenhagen was only a stepping stone. 'We don't see the process far enough advanced at this meeting to support a legal treaty,' he told reporters. 'We see it beginning with a political arrangement that would be operational, that would move elements and activities forward immediately, and that would then be followed by a negotiation of a legal arrangement.' Underpinning White House prudence is the fact that emissions-cutting legislation is still wending its way through Congress. In addition, Obama's critics have been emboldened by a scandal over hacked emails from British academics they say raises questions on the science behind climate change. The head of the UN's Nobel-winning panel of climate experts on Monday savaged the email intercepts as a suspected bid to undermine his organisation. 'Given the wide-ranging nature of (climate) change that is likely to be taken in hand, some naturally find it inconvenient to accept its inevitability,' Rajendra Pachauri, chairman of the Intergovernmental Panel on Climate Change (IPCC), told the conference. 'The recent incident of stealing the emails of scientists at the University of East Anglia shows that some would go to the extent of carrying out illegal acts, perhaps in an attempt to discredit the IPCC.' But Saudi Arabia's top climate negotiator said trust in climate science had been 'shaken' by the leaked emails. 'The level of trust is definitely shaken, especially now that we are about to conclude an agreement that ... is going to mean sacrifices for our economies,' Mohammed al-Sabban told delegates. Sabban, whose country is oil cartel OPEC's leading producer and exporter, called for an 'independent' international investigation, charging that the IPCC was unqualified to carry it out. The Copenhagen conference venue has been declared UN territory, with about 15,000 delegates, journalists and observers attending. More than half of all of Denmark's police force has been deployed to the capital and police warned they would act swiftly to quell any violent protests. 