The US president, George Bush, made a surprise concession on climate change at the weekend in the run-up to the G8 summit at Gleneagles, writes Ewen MacAskill.
The sherpas - officials who negotiate the detail of communiques in advance - completed two days of discussion at Lancaster House in London, within hearing distance of the Live8 concert in Hyde Park, on Saturday.
Until now, Mr Bush has adopted an intransigent position, insisting there is no scientific basis to conclude that there is such a phenomenon as climate change.
This is contrary to the advice of scientists around the world - not least those in the US's own academy of scientists, who have been in the lead in much of the research.
But one of the diplomats involved in the negotiations confirmed today that the US sherpa has moved and accepted a draft text in which the existence of the problem is recognised. The US sherpa also accepted the need for collective action.
The French president, Jacques Chirac, had been threatening to create trouble at the summit if Mr Bush refused to accept that there was a scientific basis. The concession at the weekend appears to be enough to satisfy the French and prevent a clash.
It appeared to be at odds with Mr Bush's interview, to be broadcast tonight, in which his tone was less conciliatory. But that is explained by the time lag – the interview was recorded last week, before the sherpas' meeting.
Mr Bush is reflecting a gradual change in mood in the US. Around 18 US states have taken steps to deal with carbon emissions, major companies are also taking action, and the US senate last week passed a resolution on climate change.
However, the president's concession - although welcomed by the other G8 countries and significant given his past opposition - is still limited. Mr Bush, unlike all the other G8 leaders, has refused to ratify the 1997 Kyoto treaty, which sets caps on carbon emissions. As far as the White House is concerned, that treaty is dead.
Tony Blair had been hoping to try to negotiate a compromise in which the US could do a deal with emerging countries such as China and India, both of whom will be represented at Gleneagles, outside the Kyoto treaty. But that now seems unlikely.
And the collective action the US is talking about is far from ambitious. The focus is on encouraging new and alternative technology and encouraging the private sector to adopt good practices.
The US concession at the weekend is important because it is a start - but it is still a long way from what scientists and environmentalists have been calling for.
Ewen MacAskill is the Guardian's diplomatic editor
