Largely unnoticed, a silent drama has been unfolding over the past weeks in the Arctic. The long-term consequences will far outstrip those of the international debt crisis or the demise of the Libyan dictatorship, the news stories now commanding media attention. The drama – more accurately, a tragedy – playing out in the North is the rapid disappearance of the polar ice cap, the Arctic Ocean’s defining feature.
In September, the sea-ice cover on the Arctic Ocean melted all the way back to the record-low level recorded in September 2007. At 4.4 million square kilometers, it was the smallest ice cover since satellite observations began 40 years ago, with 40% less ice than in the 1970’s and 1980’s.
Back in 2007, the record low stunned climate scientists, who considered it an outlier in an otherwise much slower decline in sea-ice cover. We blamed unusual wind conditions in the Arctic that year. But satellite data since then have proven us wrong. This year, we reached the same low level without exceptional wind conditions. It is now clear that we are not just seeing a steady decline of sea-ice cover, but a rapidly accelerating decline.
If this continues, we will probably see an ice-free North Pole within the next 10-20 years. Yes, that sounds shocking. But there is good reason to fear that the rate of decline will indeed continue to rise, and that satellite images of a blue polar ocean will grace the covers of news magazines sooner rather than later.
The reason is that the ice is also getting thinner. [....]
Sem comentários:
Enviar um comentário