Perilous Times and Climate Change
Arctic ice rapidly melted by climate change
* David Hambling
* The Guardian, Friday 5 November 2010
Melting ice in the Arctic. Melting ice in the Arctic. Photograph: Getty
A dramatic manifestation of climate change is the reduction of ice
cover in the Arctic. The extent of the ice has always varied with the
seasons and from year to year, creating a challenge for cartographers.
Early navigators speculated about the existence of the Northwest
Passage, a permanently ice-free route around the North American coast
leading to the Pacific.
The explorers were helped by the Inuit, who have found ways of telling
where water and land are without the aid of satellite mapping. This is
a useful survival skill in regions that freeze over or thaw out
unpredictably. One of their key indictors is "ice blink", seen as a
white line on the horizon. This is the reflection of ice on the
underside of low clouds, showing there is an ice field beyond. Its
counterpart is "water sky", in which the clouds are marked by dark
streaks, showing that there is sea water underneath.
Even with this assistance the quest for the Northwest Passage was
fruitless. In 1795, after two centuries of searching it was determined
that no continuous channel existed. The route between Atlantic and
Pacific can be traversed, but the journey takes years as vessels get
frozen in place for months at a time.
However, thinning ice has meant that in 2008 the first commercial
vessel made its way along the coast. As the ice recedes, the
navigators' dream may come true and the Northwest Passage may become a
reality at last.