Actual observations of September Arctic sea ice,
in red, show a more severe decline than any of
the 18 computer models, averaged in a dashed line,
reported by IPCC in the 2007 reports.
NSIDC
The frozen cap covering the Arctic Ocean has been disappearing much faster than predicted by the world’s top climate models — pushing the late-summer meltdown up to 30 years ahead of forecasts used for recent IPCC reports, according to a new analysis by scientists at the National Snow and Ice Data Center and the National Center for Atmospheric Research.
The extent of sea ice observed each September — the time of year when it shrinks to its smallest coverage — has been significantly lower than what has been predicted by the 18 different supercomputing models deployed by the Intergovernmental Panel on Climate Change.
The Arctic, long considered the harbinger of global warming, may be far more sensitive to greenhouse gas “forcing” than scientists realize.
“This suggests that current model projections may in fact provide a conservative estimate of future Arctic change, and that the summer Arctic sea ice may disappear considerably earlier than IPCC projections,” said lead author Julienne Stroeve, in a NSIDC news story.
The new analysis arrives amid more alarming sea ice news. After producing the second smallest ice extent for March on record, the Arctic meltdown sped up in April.