All scientists believe that the temperature of the earth is increasing due to the effect of global warming. There could be an debate regarding the cause and effect of global warming. Most of the scientists and policy makers agree to the point that it is due to human activities, still there is small number who say that there is also dominating natural cause. The bad impact of global warming has been told by in many sectors. It causes the melting of Himalayan snow which provides drinking water to downstream population. And the melted water raise the water level of the sea causing millions of people displaced. Global average temperature is increased by about 0.6C in the 20th Century. Sea levels have risen 10-20cm - thought to be caused mainly by the expansion of warming oceans. If nothing is done to reduce emissions(green house gases), current climate models predict a global temperature increase of 1.4-5.8°C by 2100. Climate change is another bad effect of global warming.
The effect of warming in North pole has been monitored these years very carefully. It has been found that the rate of shrinkage of ice on the north pole-arctic region is faster than that it was expected before. US scientists have confirmed that Arctic sea ice shrank to the smallest to the smallest area on record this year. You can see the shrinkage of ice on the picture below. The red line represents the 30 year average ice in the area.
Due to this faster shrinkage of ice, countries surrounding the arctic region have started to claim that part of the region lies in their territory. There are disputes involving all of the five - the United States, Canada, Russia, Norway and Denmark.
The US and Canada argue over rights in the North West Passage, Norway and Russia over the Barents Sea, Canada and Denmark are competing over a small island off Greenland, the Russian parliament is refusing to ratify an agreement with the US over the Bering Sea and Denmark is seeking to trump everyone by claiming the North Pole itself.
But why? do you know it?
According to US geological society, about one fourth of the worlds oil depository lies in this area and ice is still main barrier to get it. So, they hope that with less ice in the area, they will be able to dig oil wells.Russian explorers have planted their country's flag on the seabed 4,200m (14,000ft) below the North Pole to further Moscow's claims to the Arctic. Danish researchers had set sail for the North Pole to collect geological data last month, on a mission similar to Russia's trip.The month-long Danish expedition will study the Lomonosov Ridge. Russia believes the underwater feature is linked to its territory. Canada has announced plans for six naval patrol vessels and a deep-water port in the north to assert its claim to territorial waters in the Arctic.
And, according to ESA(the European Space Agency), the most direct shipping route from Europe to Asia is fully clear of ice for the first time since records began.
If you want to know much more about this here is a useful link.