BEIJING - China's President Hu Jintao may lay down a carbon intensity target for his country at a top level United Nations summit on Tuesday, experts said, as he seeks to show Beijing's commitment to fighting climate change.

A pledge from the world's biggest emitter to cut the amount of greenhouse gasses produced for each dollar of national income -- while short of an absolute cap on output -- would counter critics of Beijing who says it is taking too little action.

It could also pressure other major emitters to kickstart stalled talks on a new framework to tackle global warming, and give the Chinese negotiating team a strong bottom line going into the key negotiations in Copenhagen this December.

A senior Chinese official has already promised an important speech laying out the next policies, measures and actions that China is going to take, and in private bureaucrats say the speech will contain at least one numerical target.

Beijing has declined to give further details, but analysts, academics and campaigners say a carbon intensity goal would be in line both with domestic policies, and with a government commitment to keep economic development as its top priority even while it tackles major issues like climate change.

We understand that President Hu will lay out a carbon intensity goal, said Yang Ailun, Climate and Energy Campaign Manager at Greenpeace in China.

It is technically impossible and unfair to get developing countries to agree to binding caps but at the same time we need a sign they are taking action to avoid business as usual and in this sense carbon intensity could be a good compromise.

ALREADY ON THE BOOKS

A carbon target is earmarked for inclusion in China's still unpublished blueprint for development between 2011 and 2015.

The National Statistics Bureau is already working on how to calculate carbon emissions, because they have been told they will certainly be in the next five year plan, said one source close to the Bureau, who asked not to be named because economic plans are considered sensitive state information in China.

Beijing's worries about energy security and massive pollution had already prompted the introduction of an energy intensity target from 2006, but a carbon target will also speed up a planned boost in renewables like wind and hydropower.

Energy efficiency does not distinguish renewables from the other sources of energy, said Yang Fuqiang, director of the global climate change solutions program at WWF.

If we have carbon intensity goals, we can develop more renewables and more nuclear.

But despite its roots in a domestic political agenda, if Hu unveils a carbon intensity target at the United Nations, his choice of timing and location has a resounding political message.

We want to give the world a strong, clear signal, especially ahead of the Copenhagen summit, that we are sincere and committed, said Zhang Haibin, a professor of environmental politics at Peking University and advisor to the government.

This would demonstrate to the world that China has a very strong political will to continue cutting emissions.

TRADING, SECTORAL APPEAL

A carbon target would be hard for China's critics in the United States to dismiss out of hand, because former President George W. Bush set a carbon intensity goal for his country after rejecting the Kyoto Protocol.

It would appeal to those in the financial industry who hope to see China set up a carbon trading scheme, as the goal would boost Beijing's ability to measure output of the gasses, which is key to any market in credits to emit.

The target could also dovetail with plans touted by some players in the European Union to establish sectoral carbon crediting, to extend the carbon market after 2012.

Under this system companies in sectors like steel and power that beat a certain emission or energy intensity benchmark would qualify for carbon offset credits which would be tradable in Europe's emissions trading scheme.

Advocates of the scheme says it gives developing countries an financially viable way to contain emissions growth, although if economies expand too fast even massive improvements in efficiency might not be enough to contain dangerous emissions rises.

(Additional reporting by Gerard Wynn in London; Editing by David Fox)

Climate change China