The expanding Antarctic sea ice, which has long confounded the climate change movement, can be explained in large part by “natural climate fluctuations,” according to a new study.
The research led by the National Center for Atmospheric Research found that the negative phase of the Interdecadal Pacific Oscillation (IPO), which produces cooler-than-average sea surface temperatures in the tropical eastern Pacific Ocean, “has created favorable conditions for additional Antarctic sea ice growth since 2000.”
“The climate we experience during any given decade is some combination of naturally occurring variability and the planet’s response to increasing greenhouse gases,” Gerald Meehl, a scientist for the research center, said Monday in a statement. “It’s never all one or the other, but the combination, that is important to understand.”
The growth of sea ice at Antarctica has been a bone of contention within the man-made global warming debate since the continent began adding ice in 2000.
As the climate change publication InsideClimate News put it: “That paradox has puzzled scientists for years and given climate-change deniers fodder to dispute global warming.”
One prominent “denier,” the Cato Institute’s Chip Knappenberger, said Tuesday the results should “come as a surprise to no one that natural variability is playing a strong role in Antarctic sea ice extent trends (i.e., recent growth).”
“It is wrong to suggest that growth there suggests that global warming is not happening,” said Mr. Knappenberger, assistant director of Cato’s Center for the Study of Science. “Mostly, we have merely brought it up to point out the fact that global warming alarmists were only telling part of the story by focusing on what was going on in the Arctic.”
The federally funded study, published in the journal Nature Geoscience, offers an explanation for what the National Center for Atmospheric Research (NCAR) described in a press release as a “longstanding mystery,” namely, “Why is Antarctic sea ice expanding when climate change is causing the world to warm?”
At the opposite end of the globe, the Arctic sea ice has experienced a decline during the same period, which prompted a Greenpeace Canada scientist to declare in June 2013 that “Artic sea ice will vanish in 2013.”
While that hasn’t happened, the NASA-affiliated National Snow and Data Ice Center reported in March that Arctic sea ice peaked in 2016 at 5.067 million square miles, which set a record low winter maximum since satellites began keeping records in 1979.
The authors of the Antarctica study “also suggest that sea ice may begin to shrink as the IPO switches to a positive phase.”
Earlier this year, a study led by researchers at the Jet Propulsion Laboratory at the California Institute of Technology explained the difference in a “frontal ice zone protecting and enhancing Antarctic sea ice.”
Those findings, released in May and published in the August edition of the journal Remote Sensing of Environment, found that the Antarctic sea ice growth was “consistent with the geophysical characteristics in the southern polar region that starkly contrast to those in the Arctic.”
Another study, released May 30 in Nature Geoscience, found that “ocean currents explain why the seawater has stayed at roughly the same temperature while most of the rest of the planet has warmed,” according to the University of Washington.
“When we hear the term ’global warming,’ we think of warming everywhere at the same rate,” Kyle Armour, UW assistant professor of oceanography and atmospheric sciences, said in a statement. “We are moving away from this idea of global warming and more toward the idea of regional patterns of warming, which are strongly shaped by ocean currents.”
The latest research, conducted by a team of scientists with the NCAR and Australian Bureau of Meteorology, was funded by the Department of Energy and the National Science Foundation.
• Valerie Richardson can be reached at vrichardson@washingtontimes.com.
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