I read an Associated Press article in the San Francisco Chronicle headlined: Polar Bear Population Seen Declining, By JOHN HEILPRIN, Associated Press Writer, Saturday, September 8, 2007.
According to the article, “Two-thirds of the world's polar bears will be killed off by 2050 — and the entire population gone from Alaska — because of thinning sea ice from global warming in the Arctic, government scientists forecast Friday.”
What’s wrong with our modern polar bears? Just when they had recovered from the hunting – now banned – which had cut their numbers by the 1960s to half their population today, government scientists now forecast their doom from global warming.
What did their polar bear ancestors do during the numerous periods of natural global warming?
What?
You didn’t know that polar bears have survived many prior periods when Arctic ice was reduced as much, or more, than is currently forecast?
Apparently you’re not alone in your ignorance. Among others, you’re keeping company with government scientists.
According to a Swedish study in 1993 of the fossils of Arctic algae: “Gunilla Gard of the University of Stockholm believes that several times during the past 7000 years warm spells have melted large parts of the central Arctic Ocean.”
The uppermost algae fossils appeared to be associated with the Medieval Warm Period of AD 800 to 1200, and other fossils come from the past 7,000 years, when it was sometimes warmer than today.
Gard found similar fossils deeper down in the sediment cores, indicating that the Arctic ice partially cleared at various times from about 128,000 to 71,000 years ago - a period covering the latest interglacial and the early part of the latest ice age. However, the age of the older fossils is also uncertain. Other studies indicate that the peak sea level during the latest interglacial was a few metres higher than today, implying that peak temperatures were higher.
Obviously, polar bears existed then, and somehow survived those earlier periods when peak temperatures were higher, and Arctic ice was greatly reduced.
Why can’t modern polar bears do the same?
For hundreds of thousands of years the Earth has experienced dramatic climate changes, and polar bears somehow adapted and survived.
Other animals were not so fortunate, were not so adaptable.
Why did the saber-toothed tiger, the mastodon, the wooly mammoth, the horse in the Americas, and many other animals perish without the benefit of man-caused climate change?
Could it be possible that natural climate change was enough to cause their extinction, but that the polar bears were more hardy and adaptable, and survived?
Since Arctic ice in recent periods has been greatly reduced, and the polar bears survived, I’m betting they’ll make it through this period too, and be all ready for the coming Ice Age.
When the ice sheet over Chicago is a mile thick, as it was 18,000 years ago, I’ll bet polar bears will be enjoying seal feasts somewhere between New York and Virginia shores. Or if they’re lucky, and we have an ice age like some previous ones where the Earth almost became a white ball, polar bear feasting may extend to Florida.
And athletes need only train for the Winter Olympic Games.
No comments:
Post a Comment