ice in the Arctic Ocean this year continued to melt during the polar
winter -- the first time this has been observed in modern history.
climate scientist at Victoria University, James Renwick, says the
increase was caused by record global temperatures, unusually warm air
currents, and the surface of the Arctic Ocean being warmer than
y clear that changes in the Arctic are much more sensitive to
greenhouse gas increase. This year we'll be seeing a bit more of a
spike I suspect, but the overall trend is very much upwards. The
globe has warmed about a degree overall in the last century and the
Arctic has warmed more than two degrees."
variability", in the form of turbulent seas and strong winds
around Antarctica and the southern ocean, mean that is will take much
longer for climate change to have an effect south of the Antarctic
circle, Mr Renwick says.
Arctic sea ice is much thinner than it was 30 or 40 years ago, he
says. This makes it much easier to melt away again once the sun comes
back after the winter blackout.
sea ice has decreased dramatically over the last few
decades. Photo: James Renwick
are several months of darkness over the Arctic ocean, so you will
always get sea ice coming back in the winter, but we will reach a
point in the not too distant future where the ice will completely
melt away in the summer."
Renwick says the phenomenon is a further sign Earth's climate is
becoming more unpredictable and it is already having a roll-on
amount of snow over Siberia and northern Canada has decreased very
rapidly over the last few decades, so that will help to melt the ice
on Greenland and melt the glaciers in Alaska and so on," he