Polar sea ice reaches record low

It has been an unusual winter at the Earth’s poles. Sea ice is shrinking at an accelerating rate and its extent has fallen to a new record low.

The Arctic is registering an unusual winter this year. While temperatures hit a new record in November, it is now sea ice cover to have recorded its lowest extent at a time when it should be at its maximum extent.

Pine Island Glacier iceberg
An iceberg breaking off in the Pine Island Glacier © Nasa

In January 2017 the ice cover was 13.38 million square kilometres, the lowest extent in almost 40 years. “It is 260,000 square kilometres smaller than last year and 1.26 million square kilometres below the 1981–2010 average,” reports the National Snow and Ice Data Center (NSIDC). Since the 1970s, poles lost 3.2 per cent of sea ice extent each year, which means some 47,000 square kilometres per year.

Sea ice at poles is shrinking and warm temperatures are to blame

Researchers highlight how in January temperatures were 5 degrees higher than the 1981-2010 average in the Barents Sea, and up to 4 degrees higher in the Chukchi Sea and in the East Siberian Sea. On the other hand, in Northwest Russia and in some north-eastern areas of Greenland temperatures were 3 degrees lower than average. “This has been a most unusual winter,” said Julienne Stroeve of the National Snow and Ice Data Center. The researcher suggested that this could be linked to sea ice loss in summer and the consequent impossibility of accumulating ice during winter months.

Elisa Palazzi, researcher of the Institute of Atmospheric and Climate Science (ISAC) of Italy’s National Research Council (CNR), told LifeGate: “In October and November Arctic sea ice hit a record low. This is a problem because such a situation makes it difficult for new ice to form. And the ice that forms is thinner and thinner. The reduction of sea ice cover influences how much sunlight is absorbed, which heats up sea waters. It is a well-known feedback mechanism and a self-feeding cycle. The less ice there is, the larger the potential warming influence. That’s why the the poles are a sentinel of climate change”.

Antarctica is being affected too

Bad news also comes from Antarctica, where a massive iceberg of the Pine Island Glacier broke off, causing an ice loss 10 times the size of Manhattan. Ice melting is happening at an accelerating rate and ice extent in Antarctica is at its lowest since 1997, except in the Weddell Sea where ice is just below the average.

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