The human race faces oblivion if it fails to confront global warming, Secretary-General Ban Ki-moon warned yesterday at the UN climate conference.

Delegates debated a document that strengthened calls for deeper cuts in greenhouse gas emissions by rich nations.

Ban, who is presiding over the final days of a conference aimed at setting a deadline for talks on a pact to replace the Kyoto Protocol in 2012, urged quick action as negotiators haggled over wording that would be acceptable to all.

However, a revised text, which included guidelines for industrialised countries to cut their emissions overall by 2020 by between one-quarter and 40%, was sure to anger the United States, which opposes specific targets.

Ban said the time to act was now. "The situation is so desperately serious that any delay could push us past the tipping point, beyond which the ecological, financial and human costs would increase dramatically," he told delegates.

"We are at a crossroad," he added. "One path leads to a comprehensive climate change agreement, the other to oblivion. The choice is clear."

Talks at the conference, now in its second week, stepped up with the arrival of Ban and Australia's new premier, Kevin Rudd, who signed on to the Kyoto Protocol last week. Former US Vice President Al Gore was to arrive today after picking up his Nobel Peace Prize for sounding the alarm over global warming.

The latest document contained a new mention of "quantified national emission limitation and reduction commitments" for industrialised countries.

The draft was certain to be the object of hard negotiations. The United States has supported only voluntary emissions targets.

The US is the only big industrialised nation to reject the Kyoto Protocol - which was signed in Japan 10 years ago yesterday - and has opposed mentions of targets or emissions cuts guidelines in the Bali document.

The EU, developing countries and environmentalists have rallied in favour of including general goals in the Bali declaration.-AP