Arctic Ice Confounds Models
Heralded far and wide as a harbinger of global climate change, this year's record Arctic ice melt has the uninformed climate alarmists celebrating and the more knowledgeable scratching their heads. You see, this summer's ice retreat was predicted by no computer model and few scientists even though it possible. While climate scientists ponder what is wrong with their theories nature has carried on—no fuss, no muss, no drama. Circulation patterns are shifting and living creatures from zooplankton to megafauna are taking the change in stride. What has flummoxed environmental scientists is the simple and now demonstrated fact that successful life forms have a common trait—they are adaptable, something many scientists are not.
That ice in the Arctic has been shrinking during the summer is not news. For the past five years the summer pack ice extent was smaller than previously documented in the 34 year satellite record. This year's massive melt off has occurred under relatively normal weather conditions, with only one strong summer storm to hasten the break-up of the pack ice. But instead of vindicating their computerized prognostications, this year’s record loss has scientists questioning their models. Here is how the quandary was reported in Nature:
Computer models that simulate how the ice will respond to a warming climate project that the Arctic will be seasonally ‘ice free’ (definitions of this vary) some time between 2040 and the end of the century. But the observed downward trend in sea-ice cover suggests that summer sea ice could disappear completely as early as 2030, something that none of the models used for the next report by the Intergovernmental Panel on Climate Change comes close to forecasting.
Some are linking the unexpected meltdown to the impact of ice thickness. “There’s a tremendous spread between observations and model projections,” says Mark Serreze, director of the NSIDC. “It might be that natural variability is larger than assumed, or perhaps models don’t get the change in ice thickness right.”
Uncertainty also remains over the strength of various natural “feedbacks,” including the observed and unexpected shifts in ocean and atmospheric circulation patterns. Researchers think that lack of fine detail about circulation patterns in the Arctic Ocean could be throwing off the models. The Nature news focus mentions a 2008 survey carried out in waters north of Canada. That survey revealed 20 formerly unobserved ocean eddies, ranging from 15 to 20 kilometers in diameter. Yves Gratton, an oceanographer and Arctic researcher at the National Institute of Scientific Research in Montreal, is quoted saying: “Whether these are new features, and what role they might play for ocean-mixing processes, we don’t know yet.”
While climate scientists ponder the failure of their computer models nature is doing what it is always doing—changing. Specifically, Arctic biology is changing, as the lack of sea ice allows more sunlight to penetrate the upper ocean. The conditions that favor one set of zooplankton may not suite another, so a shift in conditions means a changing of the guard from the microscopic on up. According to Jørgen Berge, a marine biologist at the University of Tromsø in Norway, the dominant Arctic zooplankton are being replaced by other species from the Atlantic, with Calanus Finmarchicus replacing C. Hyperboreus and C. Glacialis.
It is not just the tiny critters that are changing. The Arctic cod (Arctogadus glacialis) is increasingly being edged out by its larger cousin Gadus morhua, normally found in Atlantic waters. But the displaced species are not simply perishing to make room for their cousins from farther afield. A number of species have been observed exhibiting unexpected resilience. A research cruise into the pack ice north of Svalbard, Norway, found evidence that small crustaceans (Apherusa glacialis) are less dependent on extensive sea ice than previously thought. “Just as some coastal organisms drift with the tide to retain their positions in river estuaries, these amphipods can sink to depths at which pole-ward ocean currents sweep them farther north, where they can find and colonize surviving sea ice,” reports Nature author Quirin Schiermeier.
The Atlantic cod is movin' on up to the north side.
Who would have thought that life was so adaptable, so able to roll with the punches, so... resilient? Evidently not the eco-catastrophists, who have flooded the media with predictions of massive extinctions. Berge, who led the zooplankton study, points out that the Arctic Ocean has been ice-free during the summer several times during the past 2.5 million years, and that as recently as 8,000–6,500 years ago, during a period known as the Holocene Thermal Maximum (HTM), much more of the Arctic was ice-free than it is today. “This looks like an adaptive trait that allows key Arctic-ice fauna to persist in changing sea-ice environments,” said Berge, adding that no mass-extinction events are known to have occurred during the HTM. Score that nature 1, eco-alarmists 0.
Despite fatuous cartoons in publications as staid as the Economist, the creatures of the Arctic are taking the changing conditions in the Arctic in stride. What could the summer's melt mean for the rest of us? Ralf Jaiser, a climate scientist at the Alfred Wegener Institute for Polar and Marine Research, thinks it may mean a cold and stormy winter. He found a significant correlation in 1989–2011 meteorological data between late-summer Arctic sea-ice extent and atmospheric-pressure anomalies that favor extreme weather such as prolonged cold snaps in winter. Jaiser suggests that in autumn, the open Arctic Ocean sheds heat to the high-latitude atmosphere. The warming tends to reduce the large-scale atmospheric-pressure gradient and weakens the dominant westerly winds in the Northern Hemisphere. Those west winds normally bring warm, moist Atlantic air to western Europe, moderating winter's frigid grip. Their weakening leaves the region more prone to persistent cold.
Expect more global warming this winter.
Since a weak El Niño is already building in the Pacific some are calling for a tempestuous winter in North America. Combine that with the predictions made above and the entire northern hemisphere could be in for a nasty time this year. “The impacts will become more apparent in autumn, once the freeze-up is under way and we see how circulation patterns have influenced the geographical distribution of sea ice,” says Judith Curry, a climate researcher at the Georgia Institute of Technology. But, she adds, “We can probably expect somewhere in the mid/high latitudes of the Northern Hemisphere to have a snowy and cold winter.”
That is the way nature works: warm weather followed by cold and all Earth's creatures adapting to what comes their way. All Earth's creatures except overly excited ecologists and hyperactive climate scientists, that is. The story about shrunken Arctic summer ice has run its course and the rest of humanity will get on with the important things in life—making a living, raising a family and eking out a bit of enjoyment when they can. What happens if next year there is even less ice? Or that ten years from now the Arctic is ice free during the summer? From nature's point of view not much, since this will not be the first time. Surely humanity can survive what the polar bear and Arctic zooplankton have lived through many times before.
Be safe, enjoy the interglacial and stay skeptical.
Arctic critters are taking the warm summers in stride.