This year's winter sea-ice extent around Antarctica has fallen to the third lowest since satellite observation began. Climate scientists warn that the decline is no longer a distant threat but a present crisis.
On 14 September Antarctic sea ice reached its maximum extent of 17.59 million square kilometres, about 1 million square kilometres below the long-term average, an area the size of two Spains. Researchers say the four lowest sea-ice records in the satellite era have all come in the past four years.
Dr Walt Meier, senior scientist at the University of Colorado's National Snow and Ice Data Center, said it takes some time to confirm the maximum because Antarctic ice formation varies, but with the extent falling steadily since 14 September scientists are sure this year's peak has passed.
In the normal seasonal cycle, Antarctic sea ice melts to below 2 million square kilometres in summer and refreezes to more than 17 million in winter. In recent years, however, new records have been set in both seasons.
Dr Ariaan Purich, a Southern Ocean specialist at Monash University in Melbourne, said four consecutive years of record lows show the normal rhythm of the global climate system has changed; it is not an isolated event but a sign that the ice's behaviour has changed for good.
Source: Dinajpur TV
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