The US National Snow and Ice Data Center said the minimum extent of 4.13 million sq km was reached on 16 September. The figure shatters all previous satellite surveys, including the previous record low of 5.32 million sq km measured in 2005.
Even the fabled Arctic shipping route from the Atlantic to the Pacific, the Northwest Passage, which is normally ice-bound at some location throughout the year, is open and this year, ships have been able to complete an unimpeded navigation. A fringe benefit of climate volatility?
Sea ice has a bright surface which reflects 80% of the sunlight that strikes it back into space. However, as the ice melts during the summer, more of the dark ocean surface becomes exposed. Rather than reflecting sunlight, the ocean absorbs 90% of it, causing the waters to warm and increase the rate of melting. Scientists fear that this feedback mechanism will have major consequences for wildlife in the region, not least polar bears, which traverse ice floes in search of food. And on a global scale, the Earth would lose a major reflective surface and so absorb more solar energy, potentially accelerating climatic change across the world.
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