The
area covered by Arctic sea ice reached it lowest point this week since
the start of satellite observations in 1972, German researchers
announced on Saturday.
On September 8th, the North Pole's
icy skull cap shrank to 4.24 million square kilometres (1.637 million
square miles), about half-a-percent under the previous record low set in
September 2007, according to the University of Bremen's Institute of
Environmental Physics.
The Arctic's dwindling summer sea
ice is described by scientists as both a measure and a driver of global
warming, with negative impacts on a local and planetary scale.
It is also further evidence of a strong human imprint on climate patterns in recent decades, the researchers said.
"The sea ice retreat can no more be explained with the natural
variability from one year to the next, caused by weather influence,"
Georg Heygster, head of the Institute's Physical Analysis of Remote
Sensing Images unit, said in a statement."Climate models show, rather, that the reduction is related to the man-made global warming which, due to the albedo effect, is particularly pronounced in the Arctic."
Albedo increases when an area once
covered by reflective snow or ice -- which bounces much of the Sun's
radiative force back into space -- is replaced by deep blue sea, which
absorbs the heat instead.
Temperatures in the Arctic region have risen more than twice as fast as the global average over the last half century.
The Arctic ice cover has also
become significantly thinner in recent decades, though it is not
possible to measure the shrinkage in thickness as precisely as for
surface area, the statement said.
The US National Snow and Ice Data
Center, which likewise tracks Arctic ice cover on a daily basis, has not
announced a record low ice cover. Data posted on its website only
covered the period through September 6.
