US researchers have warned that with the Arctic sea ice melting during the summer to its third lowest level on record, global warming could leave the region ice free by September 2030.
Last week, at the end of the spring and summer "melt season" in Arctic, sea ice covered 1.84 million square miles, the University of Colorado's National Snow and Ice Data Centre said in an annual report.
"This is only the third time in the satellite record that ice extent has fallen below five million square kilometres (1.93 million square miles), and all those occurrences have been within the past four years," said the report.
Meanwhile, a separate report by the National Oceanic and Atmospheric Administration (NOAA) released in August said Arctic sea ice coverage was down sharply, covering an average of 2.3 million square miles, or 22 per cent below the average extent from 1979 to 2000.
"The coverage for the month ending August was the second lowest for Arctic sea ice since records began in 1979. Only 2007 saw a smaller area of the northern sea covered in ice in August," The Telegraph quoted NOAA report, as saying.
National Snow and Ice Data Center (NSIDC) Director Mark Serreze said climate-change sceptics might seize the fact that Arctic sea ice did not hit a record-low extent this year, but said they would be barking up the wrong tree if they claimed the shrinkage had been stopped.
"Only the third lowest? It didn't set a new record? Well, right. It didn't set a new record but we're still headed down. We're not looking at any kind of recovery here. The Arctic, like the globe as a whole, is warming up and warming up quickly, and we're starting to see the sea ice respond to that," said Serreze.
"Arctic ice was disappearing by 11 per cent per decade. Our thinking is that by 2030 or so, if you went out to the Arctic on the first of September, you probably won't see any ice at all. It will look like a blue ocean, we're losing it that quickly," he added.