A leading polar researcher has warned that the Arctic may be ice-free during the summer in 20 years' time, with most of the thinning of the ice taking place over the next 10 years. Professor Peter Wadhams of the Polar Ocean Physics Group at the University of Cambridge was speaking at a meeting which announced the results of the Catlin Arctic Survey, an expedition to the Arctic which took place earlier this year with the aim of measuring ice thickness. The polar explorers, led by Pen Hadow, found that ice floes were on average only 1.8m thick. Once the ridges between ice floes are included, the average thickness rises to 4.8m, but the results are still worrying.

"The Catlin Arctic Survey data supports the new consensus view - based on seasonal variation of ice extent and thickness, changes in temperatures, winds and especially ice composition - that the Arctic will be ice-free in summer within about 20 years, and that much of the decrease will be happening within 10 years," Wadhams told the BBC. The exact impact of an ice-free Arctic on the global climate system is unknown, but scientists know that the lack of ice may accelerate global warming, as less sunlight is reflected back into space, slow down the gulf stream, which is responsible for the relatively mild climate in North-Western Europe, and dramatically change the marine eco-system.

Earlier this year Plus collaborated with Arctic Survey Education to produce a set of teaching resources exploring the science behind the survey. The resources look at climate and sea ice models, GPS and cartography, how to predict future climate trends, and how to present statistical evidence. To find out more about maths and the Arctic, read the Plus article Maths and climate change: The melting Arctic, which is based on an interview with Peter Wadhams. You can find out more about Wadhams's latest announcement on the BBC website.