Ancient Greek philosophers guessed that there was a land far to the north, where the sun never set in summer or rose in winter. They named this land Arktikos - the Great Bear - after the constellation of stars that appears above the Arctic throughout the year. They named the other end of the Earth Anti-Arktikos - “opposite to Arktikos”. The two regions are very different.

The Antarctic is a continent of land and glacier, surrounded by ocean. But the Arctic is an ocean - partly frozen - that reaches down to parts of Asia, North America, Europe and Greenland. It is that part of the Earth where average July temperatures are 10 C or lower. Its borders are close to the “tree line” - the latitude above which trees do not grow - the start of the tundra. The lands above this line experience one day in summer when the Sun never sets and one day in winter when the Sun never rises. The Arctic, far from being a snowy waste, is a vast region of great diversity - in habitats, plants, animals, cultures and people.

No ice for igloos

The arctic is like a global barometer. Arctic ecosystems are extremely sensitive to climate change. For example, when the average global temperature was 5 C lower than now, Canada was covered by an ice sheet.

Potential future temperaturesare estimated to be 10 C higher during the next 50 to 100 years. The impact of this coming change can be seen already:

* Because the ice melts earlier in the year, polar bears and other arctic animals have less time to find food, are insufficiently nourished to reproduce, and so are threatened with extinction. l Local species, such as caribou, are disappearing - some fall through thinning ice.

* New species are migrating to the Arctic. Grizzly bears are moving north.

Salmon are found in fishing nets. A robin has arrived for which the Inuit have no name.

* The ice can be so thin that hunters fall through.

* Insufficient snowfall makes for hard-packed snow. It’s almost impossible to find the ice blocks needed for temporary igloos. As a result, some Inuit have given up the nomadic life style.

* Rising sea levels threaten coastal communities.

* Melting permafrost has impaired foundations and caused homes and roads to collapse.

* In Pangirtung, north of Iqaluit in Canada, it rained for the first time ever at Christmas 2002.

* Inuit children can enjoy a dip in the Arctic Ocean on a hot summer day.

For their grandparents, this would have been fatal.

Climate change is affecting them. But the Inuit are not a nation state, and so have no place at climate change talks like those on the Kyoto Protocol in Milan in 2003.

Polar regions are far more at risk from ozone depletion than any other part of the Earth. This is because the return of sunlight in the polar spring after months of darkness and cold temperatures offers ideal conditions for the breakdown of ozone. The result is an “ozone hole” over the poles. The hole over the Antarctic covers an area of 26 million sq km. The hole over the Arctic is smaller, but the Inuit lack around a quarter of the ozone protection they should have. As a result, the native people of the Arctic have the highest incidence of skin cancer in the world.

Poisoned by pollution

Traditionally, the people living in the Arctic Circle have been among the healthiest in the world. Their diet is a healthy one. Beluga whale meat, for example, has twice the protein and 10 times the iron of beef. Sea-foods contain fatty acids that protect from heart disease. Although this has become more common with the introduction of western diets, it is still almost unknown. But the Inuit are at the top of the Arctic food chain, and increasingly, pollution is carrying poison to the Arctic. Their foods contain mercury and lead - waste from communities far to the south of them.

Our society dumps large amounts of waste chemicals in the sea. These travel to cold climates where they endure for centuries. They include chlordane and DDT. These poisons become part of the diet of polar bears - and of the Inuit.

The “North Water” - the ocean off Qaanaaq - is called a polynya - a spot that is thawed all year round in an otherwise frozen sea. Mercury concentrations in Qaanaaq mothers are 12 times greater than the level that endangers their unborn babies. Once, explorers like Peary (the first to reach the North Pole), recognised the value of the local diet. Now local health officials are discouraging traditional foods - especially for pregnant and nursing mothers. Famously, the Inuit have many words for snow (munnguqtuq, for example, is compressed snow softening with the spring).

But they have no words for contaminant or for pollution. They have never experienced it before.