The chance that developing countries would accept firm emissions-cutting targets receded on Friday, as U.N.-led talks to launch negotiations on a climate pact to succeed the Kyoto Protocol inched forwards.

About a dozen trade ministers meet in Bali at the weekend and finance ministers from Monday, their first-ever visit to the annual U.N. climate meeting normally attended by environment ministers, to help spur a booming global green economy.

Nothing's been ruled out, said Yvo de Boer, head of the U.N. Climate Change Secretariat at the December 3-14 talks being held at a luxury beach resort in Bali, Indonesia.

Binding commitments for developing countries are not off the table but are crawling towards the edge, he said of the possibility that developing nations would agree to join many rich nations in capping greenhouse gas emissions.

The Bali talks attended by 190 countries aim to agree a roadmap to work out a broader, more ambitious climate deal to succeed the Kyoto Protocol by 2009, spurred by U.N. reports warning of more heatwaves, droughts and rising seas.

Delegates must find words equally palatable to rich countries such as the United States and Japan, which want developing nations to fight climate change harder, and the likes of China and India, which want access to cleaner technologies.

De Boer said most rich nations seemed to agree it was too early to expect developing nations to cap emissions. China's emissions of greenhouse gases per capita, for instance, are about 4 tons against 20 tons per American.

Trade ministers meet this weekend on the sidelines of the conference, and will discuss a EU-U.S. proposal to cut tariffs on environmentally friendly technologies.

We think it's a good proposal, said the European Commission's head of climate change. They will certainly have a good discussion about that.

Artur Runge-Metzger highlighted global warming already wreaking havoc across Europe, citing two major heatwaves this summer that pushed temperatures to 46 degrees Celsius (115 Fahrenheit), killing hundreds of people and sparking wildfires across Greece.

It's a real major disruption to the lives of European citizens, he said.

STAR TREK

De Boer said a huge shift in world financing was needed, referring to a U.N. report in August project that net annual investments of $200-$210 billion by 2030 were needed to curb emissions, in areas from renewable energies to nuclear power.

He likened a shift in world financing to a bold mission into space in the U.S. TV series Star Trek, saying investments will have to go to places they have never gone before.

Kyoto binds 36 industrialized nations to cut emissions of greenhouse gases, mainly from burning fossil fuels, by 5 percent below 1990 levels by 2008-12. The United States opposes Kyoto, saying it would cost jobs and unfairly omits 2012 targets for developing nations.

Children from Europe, Australia and the Pacific handed a report showing that children from 17 countries had walked the equivalent of 36 times around the world by cutting out trips that would normally involve use of a car or public transport.

Little steps can lead to big results, said Ulrike Janssen, director of the Climate Alliance of children from Austria to Samoa. About 130,000 children walked a total of 1.5 million km (900,000 miles), it said.

Outside the conference centre, about two dozen representatives of indigenous groups staged a protest, wearing gags, saying they had been barred from entering the conference centre for a scheduled meeting.

Indigenous groups worry they will be marginalized by a scheme under discussion in Bali to allow poor countries to earn money by selling carbon credits to preserve their rainforests.

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(Additional reporting by Alister Doyle and David Fogarty; editing by David Fogarty)