OSLO, Dec. 10  He has said it again and again, with increasing urgency, to anyone who will listen. And on Monday, former Vice President Al Gore used the occasion of his 2007 Nobel Peace Prize lecture here to tell the world in powerful, stark language: Climate change is a “real, rising, imminent and universal” threat to the future of the Earth.

Saying that “our world is spinning out of kilter” and that “the very web of life on which we depend is being ripped and frayed,” Mr. Gore warned that “we, the human species, are confronting a planetary emergency  a threat to the survival of our civilization that is gathering ominous and destructive potential even as we gather here.” But, he added, “there is hopeful news as well: we have the ability to solve this crisis and avoid the worst  not all  of its consequences, if we act boldly, decisively and quickly.”

The ceremony marking the 2007 prize, given to Mr. Gore and to the Intergovernmental Panel on Climate Change, comes as representatives of the world’s governments are meeting on the Indonesian island of Bali to negotiate a new international agreement on reducing greenhouse gas emissions. The new treaty would replace the Kyoto protocol, which expires in 2012.

At the ceremony in the city hall in Oslo, Mr. Gore called on the negotiators to establish a universal global cap on emissions and to ratify and enact a new treaty by the beginning of 2010, two years early. And he singled out the United States and China  the world’s largest emitters of carbon dioxide  for failing to meet their obligations in mitigating emissions. They should “stop using each other’s behavior as an excuse for stalemate,” he said.