Britain's Guardian newspaper reports that Cambridge University's Peter Wadhams, an expert on ice in the Arctic, fears that the Arctic Ocean will be essentially ice free in the late summer (August-September) as soon as four years given recent observations.
Wadhams has been growing increasingly concerned since at least 2007, when the extent of summer sea ice in the Arctic had fallen to a record low of 4.17 million square kilometers. It is now markedly less, just 3.6 million square kilometers.
While he acknowledges that this presents advantages for such things as sea transport, overall he calls the development a "global disaster" and calls for urgent action, including consideration of radical steps not limited to reducing greenhouse gas emissions.
"Climate change is no longer something we can aim to do something about in a few decades' time," he wrote in an email to The Guardian, adding that "we must not only urgently reduce CO2 emissions but must urgently examine other ways of slowing global warming, such as the various geoengineering ideas that have been put forward."