* China to step up actions to slow climate change
* Warns rich nations: "unfair" demands threaten U.N. deal
By Alister Doyle, Environment Correspondent
BONN, Germany, June 2 (Reuters) - China promised on Tuesday to step up actions to fight climate change and cautioned that "unfair" new demands by rich nations could sabotage a new U.N. treaty due to be agreed in December.
"We will continue to focus on the improvement of energy efficiency, expansion of the use of renewable energy, more use of nuclear power and on reforestation," China's climate ambassador Yu Qingtai told Reuters of long-term plans beyond 2010.
And he said China was already doing a lot.
"We are pretty certain that our track record would not pale against anybody else in the world," he said on the sidelines of June 1-12 U.N. climate talks among 181 nations in Bonn.
He said China, for instance, was seeking to raise efficiency by cutting the amount of energy burnt per unit of economic output by 4 percent a year.
Washington says that China, which by most estimates has overtaken the United States as the top emitter of greenhouse gases, must do more to fight climate change under a U.N. pact due to be agreed in December in Copenhagen.
But Yu accused rich nations of introducing proposals that go beyond a roadmap for U.N. negotiations agreed in Bali in 2007.
"Copenhagen is only six months away -- instead of introducing new concepts, controversial concepts, unfair concepts, the world would be better served if we could focus on what is already agreed upon in the Bali roadmap," he said.
"If you start (questioning agreed principles), that can only meant that countries are not serious about future international cooperation. They are trying to create problems to sabotage the whole process," he said.
SINGAPORE Many developed nations, for instance, want a new yardstick that would redefine the existing group of 130 developing nations and demand more actions by the wealthier developing countries in slowing global warming.
Countries in the group of developing nations at the U.N. talks such as Singapore or the United Arab Emirates are wealthier per capita than many countries which have to cut emissions under the existing Kyoto Protocol.
"That would definitely not succeed," Yu said of an effort to redefine developing nations.
He said a 1992 U.N. Climate Convention made a basic split between nations that have caused climate change since the Industrial Revolution 200 years ago and victims -- including those that have recently become rich or major emitters.
Yu said that China's rejection of a new sliding scale did not mean however that all developing countries were able to do the same to slow climate change, such as more droughts, floods and rising seas. Under a separate principle, national circumstances vary. "We are aware that, as a country of 1.3 billion people, as a country that has enjoyed an impressive growth rate, we can do a lot more than a least developed country with a couple of million population," he said.
He said rich nations should focus on keeping pledges to curb greenhouse gases rather than place new demands on the poor. China wants the rich to cut emissions by at least 40 percent below 1990 levels by 2020 -- far deeper than cuts on offer.
A study by the Potsdam Institute for Climate Impact Research on Monday showed that promises by the rich so far amount to cuts of between 8 and 14 percent by 2020.
Asked if 40 percent was realistic when many nations say it would cripple their recession-racked economies, Yu said, "If there is political will...they can certainly do better than 8 or 14 percent. It is basically a question of political will." -- For Reuters latest environment blogs click on: blogs.reuters.com/environment/ (Editing by Louise Ireland)