"We need to get the world public to focus on the fact that climate change is not something down the line but is happening now, and that we have to work together to combat it," Annan told a news conference just before the ceremonial launch.

Annan, a Ghanaian who left the top UN job at the end of last year, said the forum aimed to convene top decision-makers from around the globe to its first annual meeting in Geneva in June 2008 to advance policy discussions on climate.

"We must all understand that this is a global issue, and that we all need to come together ... that one cannot be saved at the expense of another," he said. Climate change "is going to be a constant in all human efforts," he added.

Rajendra Pachauri, head of the UN's Intergovernmental Panel on Climate Change (IPCC) which last week shared the 2007 Nobel Peace Prize with former US Vice President Al Gore, said the forum would help to foster collaboration on the issue.

"There are vulnerable communities across the world that will need help to adapt," said the Indian scientist, who is also on the board of Annan's forum.

Former UN humanitarian relief coordinator Jan Egeland of Norway, another board member, said five times as many people were dying around the globe from natural disasters linked to climate change than from wars and other conflicts.