By Roger Harrabin
Environment analyst, BBC News
The US Congress is making the running on climate
Climate negotiations are to begin in Bonn with pressure building for the US to deliver deeper emissions cuts.
Delegates are dealing with the reality that although they are wrangling with the Obama administration, US Congress will help determine the final outcome.
President Obama has left Congress to make the running, and the Waxman-Markey Bill is reportedly being watered down as it goes through early stages.
It would deliver a cut of 4% on 1990 levels - the Kyoto Protocol benchmark.
This is a fraction of the 25-40% cut demanded of developed nations by the Intergovernmental Panel on Climate Change (IPCC).
The negotiations in Bonn, Germany, are set to begin on Monday.
And it's even less than the 60% cut urged by some developing nations who say the science has become more alarming since the IPCC report was published.
The Obama administration maintains that it represents a good start considering that US emissions have risen steadily since the Kyoto Protocol was signed. President Bush wouldn't promise to stabilise emissions before 2025.
But even the proposed cut in Waxman-Markey may be diluted further as it gets buffeted through Congress.
Brice Lalonde, the French climate adviser - and cousin of US Senator John Kerry - told BBC News: "We are in a dilemma over the United States.
"On the one hand we wish Obama well because he is a welcome change from the obstruction of the previous administration - but on the other hand he simply has to do more.
"The problem is that the United States doesn't yet have the imagination to see they can do much more. Of course they can do much more because they have so much margin, because they waste so much."
Mr Lalonde will not be impressed that Congressmen have already stripped out some clauses on improving energy efficiency.
Su Wei, the Chinese climate negotiator, told BBC News: "There's a substantial change in the US policies. The position has changed from refusing to cut emissions to some kinds of cap being set on emissions of greenhouse gases.
In that sense, we think the US policy is in the right direction but much more effort is needed."
He was supported by the Indian negotiator Surya Sethi, who told BBC News: "In simple terms they need to do more. If they believe the science - and that's what they are telling us - they need to do more."
When asked what would happen if, due to political constraints, the US could not offer deeper cuts, he said: "Then we will have to suffer the consequences."
Developing nations are also demanding huge amounts of cash from the US to buy them clean technology. The Waxman-Markey Bill will raise cash through carbon trading but it's unlikely to be enough to satisfy demands.
One ray of hope for the climate process is the strong diplomatic link forged between the US and China on the issue.
The Obama Administration needs a tangible sign of a concession from the Chinese in order to help make emissions cuts more palatable to the American public and Congress.
The campaign group WWF said the negotiating texts presented by the UN in Bonn do offer a solid basis for negotiation.
The three separate documents total 68 pages. They outline options on how to address major issues like emissions reductions, adaptation, technology, finance, carbon markets and reducing emissions from forests.
These will form the basis of talks towards an agreement in December, when negotiators meet in Copenhagen to agree on a global climate deal.
"We have a full menu of solutions on the table. Despite some gaps, the draft is a good starting point and allows reaching a level of ambition which has a chance to tackle one of the world's potentially most dangerous threats," said WWF's Kim Carstensen.
"Negotiators in Bonn can use the draft papers to develop an ambitious treaty. If they choose to water it down and go for the less ambitious options we will end up with a rotten deal".