But she also admits that Britain itself has much to do to meet the "self-inflicted wounds of our more ambitious domestic target", a 20% cut in greenhouse gases by 2020.

In an interview with the Guardian ahead of the British-chaired G8 summit in July which seeks to promote climate change and Africa as the great challenges of the decade, Tony Blair's veteran environment secretary says that the US is "doing more than people give them credit for in terms of new technology investment such as carbon sequestration.

"But the question is 'is that enough?' And the general feeling in the world community is that no, it is not doing enough. If the Americans think the Kyoto process is not a good process, do you just stand back and say you don't want to be part of that? Or do you say you don't want a process like that again?"

Mrs Beckett noted with typical acerbity that the US critique of the Kyoto accords on climate change has not been consistent.

Initially it argued that it was unfair not to have developing nations involved, then that it was unfair to force them to take part.

She said it would be "wise" for Washington to come up with its own ideas on the way forward.

"The developing nations want to be helped so they make decisions that are less damaging to the world. I do not think the dialogue in the world community is going to stand still if the US does not get involved."

It is also urgent. "The aim is to stabilise emissions, but to do that they have to peak and fall quite sharply, and most people agree that peak comes in 2020.

"So when people say it is a matter for our children, that is not right. The impact may hit our children, but the choices have to be made by this generation."

There is more awareness in Europe. But even in the United States multinational businesses as well as states and big cities are getting their act together.

General Electric is planning to cut emissions. Nine north-east states are copying Europe's infant carbon trading system, scorned by Washington, for which there are high hopes.

Mrs Beckett is also keen to stress the link between climate change and the plight of Africa.

"Dire poverty and climate degradation feed off each other. In Africa, the impact of climate change is devastating. The predicted average temperature rise in the centre of Africa is 4C (8F) and it is thought for every degree rise countries would lose 4% of GDP.

"Many areas of currently cultivated land would become infertile," she said in her Whitehall HQ in Smith Square.

Margaret Beckett is a political survivor, the sort of person who would climb out of the crater after an asteroid strike.

Now 62, the MP for Derby South was first a junior Labour education minister in 1976. As Today programme interviewers can testify, the last Callaghan protegee apart from John Prescott is still a toughie, one of Blair's safe pairs of hands.

With a clutch of global conferences to attend this year (she admits to using the Queen's Flight sometimes, but only because scheduled flights do not always ensure that a minister can be there when it matters, at the start and finish), she was keen to stay in post.

"I was hoping to be back here and I asked to be back here, but once someone starts doing cabinet reshuffles you never know where it will end up."

The domestic agenda is daunting. The government climate change review designed to get Britain back on track may be delayed until later in the year as opposed to the previous plan to publish this summer.

"I have always said it is better to get it right than publish before we are ready. We are facing some tough choices." Dismissive of claims that Labour has rested on the green laurels of John Major's government, she insists that 75% of progress so far is Labour's.

"Though it is true our emissions have gone up, if we had not had the measures in place in the original climate change programme in 2000 it would have gone up by a further 5% on top of the 2% that has occurred," she told the Guardian.

One urgent task is to see if 50% of the targeted savings can be got from renewables and efficiency measures for which the funds have only just come available.

Mrs Beckett is also a fan of wind power, a technology whose time, the cabinet's only scientist believes, has come.

"I am prejudiced because I actually think windmills are elegant.

"Also, you look round the English countryside and people are cooing over the remains of windmills we had in this country in the past.

"They were invasive new technology when they were first distributed around the countryside.

"I saw something the other day which said that in the 18th century there were something like 90,000 windmills," says Mrs Beckett.