The Arctic could lose virtually all its summer sea ice by the year 2040 – 40 years earlier than previously thought – according to a study by leading climate scientists. A rapid acceleration in the loss of sea ice seen in recent years will be dwarfed by the massive melting, up to four times faster than previously, which could take place within 20 years, the scientists predict.
If nothing is done to curb man-made emissions of greenhouse gases the Arctic Basin, from Siberia and Greenland to Canada and Alaska, could be open water in summer within the lifetime of today’s children.
The findings, part of the fourth assessment of the International Panel on Climate Change (IPCC) due next year, are published today in the journal Geophysical Research Letters.
Marika Holland of the National Centre of Atmospheric Research in Boulder, Colorado, the report’s lead author, said: “We have already witnessed major losses in sea ice, but our research suggests that the decrease over the next few decades could be far more dramatic.
An ice-free Arctic would almost certainly lead to the demise of many indigenous people and their way of life, along with the extinction of the polar bear and other species that rely on the year-long sea ice for survival.
The loss of sea ice could also lead to more serious long-term climate change, such as the disruption of the North Atlantic current that brings mild winters to Britain, or a more rapid loss of the Greenland ice sheet.
Their forecast may, however, already be out of date and over-optimistic, argues Professor Chris Rapley, head of the British Antarctic Survey.
He said a recent study by the Global Carbon Project suggested that emissions were rising more than twice as fast as in 2000, which was likely to speed up ice-loss even further.
“The study may be an underestimate of when the Arctic summer ice might be all gone,” he said. “It could well be their assumptions are more optimistic than they might be.”