By Duncan Bartlett
Business reporter, BBC News
Polar bears are moving further north in search of food, says an explorer
Nowhere on earth provides more dramatic evidence of the earth's changing climate than the Arctic. The sea ice is receding. Glaciers are melting.
And even the coldest remotest parts of the region are becoming gradually warmer.
Arctic explorer Pen Hadlow says: "I will always remember seeing a mother polar bear with a young cub just three miles from the North Pole in the middle of April.
"Why would she take it that far north? The answer is that there's a good supply of food in the form of seals.
"The polar bears presence at the North Pole is a classic biological indicator of increased areas of open water at that time of the year, enabling the seals to breath and move further north."
The changing climate does not just affect the polar bears and the seals. It has also made the Arctic more acceptable to human beings.
A spectacular example came in August 2007 when a Russian team used submarines to plant a flag on the waters underneath the North Pole itself.
It won them praise from their government but provoked the rest of the world to ask why they had done it.
Norway's foreign minister Jonas Gahr Store says it was a provocative and unnecessary act.
"I think it was a PR stunt. It has no legal legitimacy whatsoever. Up in the Arctic, there will be waters that are beyond any country's territory and that makes them - according to the law of the sea - mankind's heritage."
But even if the North Pole is beyond Russia's legitimate territory, there are signs the Russians are already prepared to greatly increase oil and gas production in the Arctic.
They are now planning to access the Shtokman field in the Barents sea, one of the world's largest natural gas fields.
It is not just the Russians who have realised the new accessibility of the Arctic caused by global warming could bring them benefits.
Other northern states such have seen the opportunities too.
Accessibility to the Arctic due to global warming may bring more industry
Greenland's foreign affairs spokesperson Tove Sovndahl Pederson says: "Greenland is extremely mineral rich and we have some deposits that so far have been difficult to access because of the ice but now that we see the Greenland ice sheet is receding, these minerals are becoming more accessible and we are very excited about this because it will make an important contribution to our economy."
But there is concern that further oil and gas exploration in the Northern Arctic could lead to catastrophic pollution.
So far, there is no system in place to clear up oil spillages from ice. This worries explorer Pen Hadlow.
"There is a terrible irony that the very thing that is driving climate change and the recession of the sea ice, that is the combustion of oil and natural gas and coal, is the very thing that they are looking to extract from the sea bed and therefore further exacerbate the issue of global climate change and further sea ice melting."
For the time being, huge logistical obstacles deter nations from turning the Arctic into a commercial mining zone.
But as precious resources like oil, gas and minerals grow scarcer and more expensive, the ice fields of the far North will attract ever greater interest from those who dream of making money.