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Earth could plunge into sudden ice age
‘Big Freeze’ about 12,800 years ago happened
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2 Dec 09 - There is no reason why such a freeze shouldn't
happen again, says this article by Charles Q. Choi. Ironically, says
Choi, "it could be precipitated if
ongoing changes in climate force the
Greenland ice sheet to suddenly melt."
I love the headline, and I agree with the
subtitle. I also agree
that such a freeze could - or rather, will - happen
again. It's all
part of the ice-age cycle.
However, the words "ongoing changes in climate" are a
sneaky
way of trying to blame humans. That's wrong. Humans
have
nothing to do with it. Climate always changes. That's
what
climate does.
(Actually it's not sneaky, it's blatant,
because if you click on
the link underlying those words you'll find an article
that
explicitly blames humans.)
"Starting roughly 12,800 years ago," the article continues, "the Northern Hemisphere was gripped by a chill that lasted some 1,300 years. Known by scientists as the Younger Dryas and nicknamed the "Big Freeze," geological evidence suggests it was brought on when a vast pulse of fresh water — a greater volume than all of North America's Great Lakes combined — poured into the Atlantic and Arctic Oceans."
Did humans cause the Younger Dryas? No. Did humans
cause
all of the other ice ages? No. But let's blame them
anyway.
Temperatures go up? Blame humans. Temperatures go down?
Blame humans.
The article goes on to describe how temperatures plummeted "over the course of a few months, or a year or two at most," as North America's glacial Lake Agassiz burst its banks, diluting warmer water in the North Atlantic. (I discuss this giant flood in Not by Fire but by Ice; chapter 15, "Noah's Deluge".)
"It would be like taking Ireland today and moving it up to above the Arctic Circle, creating icy conditions in a very short period of time," says isotope biogeochemist William Patterson at the University of Saskatchewan, who, along with his colleagues, made the startling discovery while studying mud cores from an ancient lake in Ireland.
There is no reason why a big freeze shouldn't happen again, says Patterson. "If the Greenland ice sheet melted suddenly it would be catastrophic."
Sure, IF that should
happen. But there's no reason to expect
the Greenland ice sheet to suddenly melt. Temperatures
have
been declining since 1998, and we've had record
snowfall
around the world. If anything, we should expect the
Greenland ice sheet to grow.
"This kind of scenario would not discount evidence pointing toward global warming," says the article. "After all, it leans on the Greenland ice sheet melting."
"We could say that global warming could lead to a dramatic cooling," said Patterson in an interview with LiveScience. (Maybe they should take away the "v'" and call it LieScience.)
"People assume that we're political, that we're either pro-global-warming or anti-global-warming, when it's really neither," Patterson added. "Our goal is just to understand climate."
If their goal is "just to understand climate," then
why don't they,
and other climate scientists, include the known climate
cycles in
their models? These cycles have been known and
acknowledged
since the 1970s.
In 1976, scientists at Lamont-Doherty Earth
Observatory
spearheaded a project called CLIMAP (Climate:
Long-range
Investigation Mapping and Prediction) to map the
history of
the oceans and climate.
They discovered that ice ages begin or end, almost like clockwork,
every 11,500 years. It's a dependable, predictable,
natural cycle.
Pacemaker of the Ice Ages, they called it.
They drew up a chart of the cycle (below).
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Changes in global ice volume during the last 500,000
years, as determined from CLIMAP isotopic measurements. |
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Chart is from John and Katherine Imbrie's book Ice Ages: Solving the Mystery, by permission of Enslow Publishers. Data from J. D. Hays et al., 1976, by permission J. D. Hays. (Chart is also published in Not by Fire but by Ice, page 211.) |
- See the sharp peaks every 100,000 years or so? Each peak marks the abrupt end of a period of warmth similar to today's and the catastrophic beginning of a new ice age. (These peaks are caused by a process called orbital stretch - the periodic stretching and shrinking of our elliptical orbit around the sun. I discuss orbital stretch in Not by Fire but by Ice.)
- See where we are today? (At the far right side of the chart?) We're at the tip of the highest peak ever, teetering on the knife-edge of disaster. We haven't been that high on the chart for half a million years.
- And do you see what happened--without exception--every time we got that high on the chart?
- Instantaneous ice age.
- The next ice age could begin any day.
- Did humans cause every one of those warmings during the past half-a-million years? No.
- Did humans cause every one of those ice ages? No.
- Stop trying to blame humans for climate change!
See entire article:
http://www.msnbc.msn.com/id/34242705/ns/technology_and_science-science/
Thanks to Jason Spies, Craig Adkins, Tim Spence and Chuck Clancy for
this link