BALI, Indonesia – Delegates and scientists from around the world opened the biggest-ever climate change conference yesterday, urging rapid progress in building a new international pact by 2009 to combat global warming – or risk economic and environmental disaster.

Some 10,000 conferees, activists and journalists from nearly 190 countries gathered on the resort island of Bali for two weeks of U.N.-led talks that follow a series of scientific reports this year concluding that the world has the technology to slow global warming, but must act immediately.

The Bali meeting will be the first major climate change conference since former Vice President Al Gore – due to arrive next week – and a U.N. scientific council won the Nobel Peace Prize in October for their environmental work, fueling the growing sense of urgency as ice-caps melt, oceans rise and extreme weather increases.

“The eyes of the world are upon you. There is a huge responsibility for Bali to deliver,” said Yvo de Boer, the executive secretary of the conference. “The world now expects a quantum leap forward.”

The immediate aim of the Bali conference will be to launch negotiations toward a pact to replace the Kyoto Protocol on global warming when it expires at the end of 2012, and set an agenda for the talks and a deadline. The U.N. says such an agreement should be concluded by 2009 in order to have a system in place in time.

A main thrust will be to draw the United States, the world’s largest emitter of greenhouse gases blamed for global warming, into the process. Washington did not ratify the Kyoto Protocol, arguing that mandatory cuts in emissions would harm the economy and calling into question the veracity of global warming science.

“One of the stumbling blocks so far has been the fear of economic hardship,” said Indonesian Environment Minister Rachmat Witoelar, the host of the Bali meeting. “Though the cost will be significant … it’s insignificant compared to the damage that uncontrolled climate change will wreak.”