London - The Arctic ice pack has dramatically expanded – despite years of doom-laden predictions that it was melting away for good.
British scientists discovered that it grew by more than 40 percent in 2013 thanks to cooler than expected temperatures.
The findings by experts at University College London suggest the polar cap is more resilient than first thought and is able to quickly bounce back. Despite several warm summers there is still about a third more ice in the region than there was five years ago.
Scientists said they were shocked at the speed of recovery in such a short time.
The resurgence shows how much care needs to be taken when assessing claims about climate. For years an industry has grown up around global warming – based on pressimistic forecasts from scientists and politicians that the ice caps would have disappeared by now.
A major report last year by the Intergovermental Panel on Climate Change gave a grim assessment, saying Arctic sea ice had decreased since 1979 at a rate of 3.5 to 4.1 percent per decade.
Three years ago Professor Peter Wadhams of Cambridge University forecasted that the Arctic would be ice free by 2015 – or 2016 at the latest. The US Navy predicted last year that melting sea ice would mean the Arctic would be navigable during summer months by 2030 for the first time. And strong claims that the caps would disappear by 2014 have been made by US politician Al Gore and vice president John Kerry. Those assessments now seem unlikely on current findings.
And at the other end of the planet, Nasa reported that sea ice at the Antarctic was at its greatest extent since records began in 1979.
The UCL researchers found that Arctic ice had melted by 14 percent between 2010 and 2012. But it then increased in volume by 41 percent two years ago when the Arctic summer had some of the coolest temperatures since the late 1990s
Last autumn, the ice only melted by six percent, meaning it is still considerably thicker than in 2010.
Overall there were five percent fewer days when the temperature was consistently above freezing in 2013 than in 2012 – causing the remarkable expansion.
Study leader Rachel Tilling admitted: “We were quite surprised by the findings.”
She added: “Although models have suggested that the volume of Arctic sea ice is in long term decline, we know now that it can recover by a significant amount if the melting season is cut short.”
The Arctic is a significant habitat for wildlife, particularly polar bears, and is also believed to have huge significance for the world’s climate. Many scientists say melting could result in warmer oceans and an overall rise in global temperatures.
The experts at UCL and Leeds University used 88 million satellite readings to calculate the volume of sea ice across the Arctic. They also found that even though September 2012 was “the record minimum” extent of sea ice in the Arctic, there was thicker autumn ice around Greenland than in previous years. They said it proved that shrinking ice extent does not necessarily lead to a drop in the volume of ice.
However, scientists believe there is still roughly 40 percent less Arctic ice than in the 1970s when the polar cap was first assessed.
Co-author Andy Shepherd said: “We still expect temperatures to rise in the future, and so the events of 2013 will have simply wound the clock back a few years on the long-term pattern of decline.”
Ed Hawkins, Professor of Climate Science at the University of Reading, also said the long term prospects were bleak. But Benny Peiser, of the Global Warming Policy Foundation, said: “The good news about this study is it is not a one-way street, there are periods where the ice can recover.”