Their ancient way of life is in unprecedented peril. Their very land is melting beneath their feet.

Even the endless night of the Arctic winter, which should be one of nature's most immutable constants, may be changing.

It too appears to have fallen victim of the abrupt warming of the global climate which almost every one on earth - apart from the government of the United States - believes is exacerbated by the polluting industries of the modern world.

But now the 155,000 Inuit, also known as Eskimos, scattered along the northern rim of Canada, Greenland, Alaska and Siberia, say the climate change that threatens their existence is also a violation of their human rights, and that the US, responsible for 25 per cent of the planet's greenhouse gases, is largely responsible.

The human rights, say the Inuit are the most basic ones, the rights to life, health and property.

"We're an adaptable people, but adaptability has its limits," says Sheila Watt-Cloutier, the head of the Inuit Circumpolar Conference, the group recognised by the United Nations as representing the Inuit people.

"Something is bound to give, and it's starting to give in the Arctic, and we're sending that early warning signal to the rest of the world."

Yesterday, at the international climate change conference in Buenos Aires, the Inuit were to make their move by announcing they would demand a ruling from the the Inter-American Commission on Human Rights that as the prime source of greenhouse gas pollution, is in violation of the commission's own norms.

The prospects for success are unclear.

A Washington environmental lawyer here close to the case, says: "The question is, does what the US government is doing, or rather what it is not doing, constitutes a deprivation of human rights for the Inuit.

"You can argue that these deprivations are already occurring because of global warming, the loss of sea ice, the erosion of coastlines, and the loss of hunting grounds.

"That raises the issue of whether there is a causal link with the activities of the US, responsible for 25 per cent of the emissions held to blame for climate change."

The feasibility of anyone suing over global warming was raised this month by scientists who made a fresh analysis of the summer heatwave of 2003, when there was 20,000 extra deaths across Europe, many from heat-stroke and heart attacks.

In a study in the journal Nature, scientists from Oxford University and the Met Office's Hadley Centre estimated that such a heatwave is now four times more likely as a result of man-made influences on the climate.

They also calculated that these human influences - carbon dioxide emissions from the burning of fossil fuels - were to blame for 75 per cent of the increased risk of a repeat of such a heatwave.