The approximately 2 million square miles of ice coverage left on that date was still much higher than last year’s record low.
In September 2012, the collapse of sea ice broke all records when the polar ice cap melted to only 1.3 million square miles. This year’s minimum was also considerably lower than the average set over the past 30 years.
Climate models have consistently projected that there will be large variations in summer ice extent from year to year. But some climate change skeptics claim the “rebound” of the Arctic sea ice is proof that the prevailing scientific view of a warming planet is wrong.
“What matters is that the 10 lowest (sea ice) extents recorded have happened during the last 10 years,” said Walt Meier, a glaciologist with NASA's Goddard Space Flight Center in Greenbelt, Md. “The long-term trend is strongly downward.”
This summer’s reduced melt kept the Northwest Passage littered with more ice than since 2007. The Northern Sea Route north of Russia also did not open up, to the dismay of some shipping companies looking for a cheaper summertime route between Europe and Asia.
Meanwhile in the Southern Hemisphere, The Antarctic sea ice extent was approaching the annual maximum, reaching a record high for the date on Sept. 16. It’s about 3.9 percent higher than the 30-year average.
The southern expansion was due to stronger hemispheric winds brought on by climate change that shoves the ice together around Antarctica rather than letting it drift northward and melt, as was more typical decades ago.
This helps highlight why scientists are more concerned by the Arctic ice shrinkage than by the Antarctic ice expansion, the U.S. National Snow and Ice Data Center says.
Photo: Transport Canada