Starting Monday, the nations of the world are meeting for two weeks in Poland to continue negotiations over the most ambitious climate-protection treaty the world has ever seen.

The forum of the 192-member U.N. Framework Convention on Climate Change in Poznan, Poland, comes halfway along a two-year process launched by the global community in Bali, Indonesia, in 2007. Officials hope it will culminate in an ambitious global climate-protection deal at the final summit, in Copenhagen, Denmark, at the end of next year, to succeed the Kyoto Protocol that expires in 2012.

"We shoulder the responsibility to prevent changes that could lastingly disturb the symbiosis between humankind and nature," Polish Prime Minister Donald Tusk said at the opening of the meeting.

Experts agree that by 2050 the global community will have to cut its carbon dioxide emissions at least by half compared with 1990 levels to limit the temperature increase to roughly 2 degrees Celsius. Failure to take action would cause irreparable damage to the planet's climate system, experts claim. Any increase greater than 2 or even 3 degrees Celsius would have catastrophic consequences for global security.

"Huge droughts and floods, cyclones with increasingly more destructive power, tropical disease pandemics, a dramatic decline of biodiversity -- all these can cause social or even armed conflicts and migration of populations at an unprecedented scale," warned Maciej Nowicki, Poland's environment minister.

Pre-conference debate has been overshadowed by the global financial crisis. Several nations of the European Union, once the leader regarding climate protection, have warned that the bloc's emission-reduction goals may prove too costly. An EU summit next week, just when the UNFCCC meeting reaches its climax, will decide the bloc's real commitment.

Yvo de Boer, the United Nations' top climate official, said the financial crisis should not distract from the fight against climate change. He called on delegates to "increasingly focus on how the climate change regime could become self-financing and to link climate change policies to economic recovery."

The conference also will pit the world's richest nations against developing nations including China and India.

While these quickly growing nations call on the West to help finance them to make their economies grow more sustainably, Washington, which has not ratified the Kyoto Protocol, in the past has called on India and China to agree to emissions reductions before it was willing to make concessions herself.

This strategy may change soon. Observers are hopeful that incoming U.S. President Barack Obama will change rhetoric and action when it comes to climate protection. During his campaign, he pledged to reduce U.S. emissions to 1990 levels by 2020 and by 80 percent by 2050, in the process spending $150 billion over 10 years to boost renewable energy generation.

While the current administration will send its conservative delegation to Poznan, several Obama advisers will be present, including Sen. John Kerry, D-Mass., the incoming head of the Senate Foreign Relations Committee.

Conference delegates will work with an 82-page document containing proposals for action submitted over the past year.

Observers hope the delegates will be able to compress this into a blueprint to pave the way for negotiations with the world's leading emitters over concrete ways to reduce emissions leading up to the Copenhagen summit. The Poznan summit is also expected to make progress on stopping the loss of the world's forests.

Angela Ledford-Anderson, director of the international global warming program with the Pew Environment Group, said time is short for real, binding agreements to be hammered out at Poznan and then Copenhagen.

"There's a real need to get as far and be as specific as they can before Copenhagen, but the most important things are the broad outlines of the agreement -- how they're going to mitigate (emissions), how they're going to adapt to climate change, what is the range of financing available," she told BBC News. "It might be more important for them to get the architecture in place; and once they've agreed on that, they could spend the next year coming up with the targets."