By Environment Correspondent Alister Doyle

OSLO (Reuters) - Fifteen years ago, fears about man-made climate change were enough to bind most of the industrialized world into a treaty that was flawed but at least seemed to cement the principle that greenhouse gases must be cut.

Yet now - with levels of those gases much higher and climate change more evident in extreme weather - economic slowdown and arguments over who should pay have all but killed any chance of a meaningful extension to the expiring Kyoto Protocol.

Almost 200 nations meet in Doha, Qatar, from November 26 to December 7 to at least try. But Russia, Japan and Canada, major economies that signed the Kyoto Protocol in 1997, have already said they will not sign up to emissions cuts beyond December 31.

The huge developing economies of India and China, now the world's biggest emitter of gases such as carbon dioxide from fossil fuels that trap the sun's heat, were anyway not obliged to cut emissions under the Kyoto process.

But campaigners say failure to extend Kyoto will also hobble Doha's much harder challenge: to work on an entirely new treaty to cap emissions from all countries including developing nations, due to be agreed by 2015 and go into force in 2020.

Meanwhile, man-made climate change is ever more visible.

Arctic sea ice thawed in September to its lowest recorded level, and extreme heat waves and drought have hit the United States and Russia more often than would be expected from historical records, a World Bank report said last week.

Greenhouse gas levels hit a new record last year, despite a world economic slowdown.

Even if all countries fulfill existing commitments, the world will warm by more than 3 degrees Celsius (5.4 Fahrenheit) by 2100 - more than the 2 degrees that the countries of the world say should be the limit, and dwarfing the 0.8 degree rise seen since 1900.

HEATWAVES AND FLOODS

Rising sea levels and more floods, heatwaves, storms and droughts will be the result, the scientists of the U.N. climate panel say. Less predictable rainfall and higher temperatures are likely to disrupt food and water supplies for a rising population.

The probability that the change is man-made is now at least 90 percent, the panel says.

"It's abundantly clear every day that what's been committed to is far from what's needed, and you can't wait until 2020 to be increasing the level of ambition," said Jennifer Morgan of the World Resources Institute in Washington.

But Russia, Canada and Japan have said they will not make cuts under a Kyoto Two because they would be meaningless when emerging nations led by China and India have no targets.

Kyoto bound almost 40 developed nations to cut emissions by an average of at least 5.2 percent from 1990 levels by 2008-12, but also established carbon trading mechanisms, which Russia, Canada and Japan want to preserve.

The United States never ratified the Kyoto deal, arguing that it would cost U.S. jobs and that it should include emissions cuts for poorer nations.

If it is allowed to expire, the world will have no legally binding climate plan from 2013, merely national emissions cuts by countries including the European Union, Australia and Ukraine that account for just 12 to 14 percent of global emissions. Continued...