How arctic animals are coping with less sea ice - Coeur d'Alene Press: Weather Gems

How arctic animals are coping with less sea ice

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Posted: Monday, October 22, 2012 8:29 am

My friend, Cecil Hathaway, a regular contributor to my column, recently sent me an interesting article that Matt Ridley wrote on Sept. 22 of this year for the Wall Street Journal entitled; "What Arctic Foxes Know About Global Warming."

Mr. Ridley mentioned what climate scientists have pointed out since mid Sept-ember that 2012's sea ice melt in the Arctic regions was the greatest since such records began in 1979, the opposite 'extreme' to the most ice ever measured during the same time span, also this September, in the Antarctic regions near the South Pole. (Are you confused yet?)

Svend Funder of the Danish Museum of Natural History in Copenhagen said recently that "Arctic melts like those in recent years have happened before, especially during the 2,500 years in the 'Holocene Optimum' period, when Arctic summer temperatures were at least two or four degrees Celsius (four to eight degrees Fahrenheit) warmer than today."

I should likewise mention that even 1,000 years ago during the days of Leif Ericsson, the mighty Viking Chieftain, the annual summer ice melt in the Arctic regions was at least a third more than this era's melt.

Despite the record warm temperatures that occurred during the Holocene Optimum period and a nearly ice-free Arctic Ocean during the summer and early fall seasons, there is no evidence of a collapse of the polar bear population or other Arctic animals for that matter like Arctic foxes.

According to Durham University in Great Britain, Greger Larson and his colleagues found that the remains of 17 Arctic foxes discovered in Iceland that died during the warm period of 800 to 1200 A.D. shared just a single genetic code, while the modern Icelandic fox population now have five different genetic signatures.

This means that sometime during the so-called 'LITTLE ICE AGE' between 1350 and 1850 A.D., genetically diverse Eurasian foxes interbred with Arctic foxes that reached Iceland via a greatly expanded area of sea ice.

As far as polar bears are concerned, they have thus far survived the recent period of rapid ice melt in the Arctic regions. But, many climate studies suggest that, if this rapid summer ice melt continues into the mid-century decades, at least half of the polar bear population could disappear.

Polar bears need ice as a platform in order to hunt for their main food source, seals. As the Arctic ice vanishes, the bears must travel much greater distances in order to find food.

Recently, polar bear researchers in the Arctic have reported seeing things that they have never before witnessed. They've seen very emaciated bears, practically starving, bears that have drowned in the open seas and even bear 'cannibalism.' Ice is certainly a critical component of the polar bear environment.

Scientists have been able to directly link the availability of ice to polar bear population rates of growth.

Like other predators near the top of the global food chain, polar bears have a low reproductive rate. One or two cubs are born during the midwinter period and usually stay with their mother for at least two years. Consequently, females breed only once every three years. The cubs won't be able to reproduce until they're at least 5 or 6 years old.

From late fall to mid spring, polar bear mothers live with their cubs in snowdrifts on ice or even land. Eskimos call polar bears, "ice bears," because they usually hunt them on floating packs of sea ice.

But, if there is no sea ice, polar bears can't drag seals that they've caught onto a solid surface, their icy platforms. Simply put, less ice, less hunting, more death from starvation. Longer-term, it's not a pretty picture.

But, as Matt Ridley says; "If this current warming is supposed to a 'global' event, shouldn't we be seeing the sea ice retreat at BOTH ends of the world?"

NORTH IDAHO WEATHER REVIEW AND LONG-RANGE OUTLOOKS

After a record mid summer and early fall drought, we finally received our first measurable rain in 53 days in Coeur d'Alene last Saturday. As of this Thursday morning, Oct. 18, .66 inches of precipitation had fallen in the past five days bringing our 2012 rainfall total up to a much above normal 29.98 inches.

The Rathdrum and Twin Lakes areas gauged nearly an inch of rain in the five-day period ending at 8 a.m. on Thursday. This juicy storm system certainly helped the tinder-dry situation in the nearby forests. With more rains and mountain snows likely on-and-off between now and early November across North Idaho and the rest of the Inland Empire, it's likely that the 2012 fire season will end without major fire disasters in our part of the country.

If the final 11 weeks of 2012 prove to be wetter than usual across the Inland Northwest, it's possible that we could still threaten our town's all-time single year rainfall mark of 38.77 inches set in 1996.

It's hard to believe that we're near 30 inches of precipitation for 2012, thanks to the wettest spring season since at least 1895, especially considering the fact that we had just .23 inches of moisture locally between July 20 and Oct. 13. That 12-week span broke the record of .47 inches, by less than half, set back in 1934 during the midst of the infamous Dust Bowl Days of the 'Dirty 30s.'

Longer-term, it appears as if our weak El Nino in the waters of the Pacific Ocean has literally "bitten the dust." This could mean increased storminess during the upcoming winter of 2012-13, if El Nino doesn't return by Christmas.

Randy Mann will update his August charts next week in 'Gems' on both sea-surface temperatures and solar activity.

The following week, on Nov. 5, just ahead of the presidential election on Nov. 6, I'll issue my annual winter of 2012-13 snowfall predictions for dozens of towns and cities in the Inland Empire. Stay tuned.

Cliff Harris is a climatologist who writes a weekly column for The Press. His opinions are his own. Email sfharris@roadrunner.com

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