3rd April, 2010
The amount of sea ice covering the Arctic dramatically increased last month, reaching levels not seen at this time of year for nearly a decade.
Returning ice – after years of declining cover – has astonished climate scientists who blamed unusually cold weather over the Bering Sea.
Researchers said they recorded the most ice in March since 2001 – and that the cover is approaching long-term average levels for the first time in ten years.
The scientists who released the data stressed that last month’s rise was part of yearly variations in ice cover and could not be taken as a sign that global warming is coming to an end.
But sceptics argued that the findings undermined ‘alarmist’ claims that the North Pole could be free of summer ice by 2013.
The unusual trend last month is revealed in figures published by the U.S. National Snow and Ice Data Centre in Colorado.
In a typical year, Arctic ice cover peaks in mid-March and starts to fall as milder weather arrives.
But this year, levels continued to grow in the second half of March. Dr Mark Serreze, of the NSlDC, said parts of the Arctic were going through an unusually cold spring – but that other areas were warmer than normal.
He added: ‘What this doesn’t show is any indication that global warming is over. If you look at the Arctic as a whole we might get to average amounts of sea ice for the time of year. But the ice is thin and quite vulnerable and it can melt very quickly.’
The best measure of the health of the Arctic was not only the amount of cover, but also the thickness of ice, he said.
But Dr David Whitehouse, of the Global Warming Policy Foundation think-tank, said: ‘The recent observations make the 2007 projections that the region would be ice free by 2013 look very unrealistic.’