By Elizabeth Blunt
BBC News, Buenos Aires
Environmentalists have attacked US claims that America is doing as much to curb global warming as any other nation that signed the Kyoto deal.
The US says it will do more on climate than many in Europe
They were reacting to statements by the US government delegation at the international meeting on climate change in the Argentine capital, Buenos Aires.
A speaker from the US section of Greenpeace accused the government for censoring the work of its scientists.
Jessica Coven said the US was using the science to delay the need to act.
Ms Coven also said the US government's much-vaunted technical innovation was largely misdirected.
"They're looking at hydrogen fuel cells that won't be available for widespread use for 20 to 30 years and the hydrogen for the president's initiative often comes from fossil fuel sources, especially coal," she said.
"All it does is move the emissions from the tailpipes of cars to the smokestacks of power plants."
Passers-by in Buenos Aires were treated to the curious sight of US President George W Bush apparently dancing in the rain outside the city's main conference centre.
In fact, it was a masked Greenpeace campaigner under an artificial downpour.
But the environmentalists are out in force here, meeting every statement from the American delegation with a riposte of their own.
Dancing "President Bush" proved to be a hit in Buenos Aires
The American presence in Argentina's capital is large and varied, reflecting the wide range of views within the US itself.
The states mostly on the eastern seaboard, which are taking their own action on carbon emissions, will be hosting an event during the meeting.
And there is also a fair number of American businessmen, some of whom are clearly tempted by the money to be made in emissions trading and in international projects.
Ms Coven says they may have the best chance of changing Mr Bush's policies.
"[President Bush] does care about business and right now we do see a mood in the business community where they realise they're missing a massive market opportunity," she said.
"So the business community is looking quite closely at this and I think it will start putting a lot more pressure on the president to rejoin the international community."
This argument will run throughout the conference, but it feels like a dialogue of the deaf - each side apparently convinced by its own arguments and with little chance of either side changing its mind.