Free Republic
Browse · Search
News/Activism
Topics · Post Article

Skip to comments.

Greenland Ice Core Analysis Shows Drastic Climate Change Near End Of Last Ice Age
Physorg ^ | 6-19-2008 | University of Colorado

Posted on 06/19/2008 3:33:44 PM PDT by blam

Greenland ice core analysis shows drastic climate change near end of last ice age

Caption: The North Greenland Ice Core Project camp. Credit: NGRIP

Temperatures spiked 22 degrees F in just 50 years, researchers say Information gleaned from a Greenland ice core by an international science team shows that two huge Northern Hemisphere temperature spikes prior to the close of the last ice age some 11,500 years ago were tied to fundamental shifts in atmospheric circulation.

The ice core showed the Northern Hemisphere briefly emerged from the last ice age some 14,700 years ago with a 22-degree-Fahrenheit spike in just 50 years, then plunged back into icy conditions before abruptly warming again about 11,700 years ago. Startlingly, the Greenland ice core evidence showed that a massive "reorganization" of atmospheric circulation in the Northern Hemisphere coincided with each temperature spurt, with each reorganization taking just one or two years, said the study authors.

The new findings are expected to help scientists improve existing computer models for predicting future climate change as increasing anthropogenic greenhouse gases in the atmosphere drive up Earth's temperatures globally.

The team used changes in dust levels and stable water isotopes in the annual ice layers of the two-mile-long Greenland ice core, which was hauled from the massive ice sheet between 1998 to 2004, to chart past temperature and precipitation swings. Their paper was published in the June 19 issue of Science Express, the online version of Science.

The ice cores -- analyzed with powerful microscopes -- were drilled as part of the North Greenland Ice Core Project led by project leader Dorthe Dahl-Jensen of the Centre for Ice and Climate at the Neils Bohr Institute of the University of Copenhagen. The study included 17 co-investigators from Europe, one from Japan and two from the United States -- Jim White and Trevor Popp from the University of Colorado at Boulder.

"We have analyzed the transition from the last glacial period until our present warm interglacial period, and the climate shifts are happening suddenly, as if someone had pushed a button," said Dahl-Jenson.

According to the researchers, the first abrupt warming period beginning at 14,700 years ago lasted until about 12,900 years ago, when deep-freeze conditions returned for about 1,200 years before the onset of the second sharp warming event. The two events indicate a speed in the natural climate change process never before seen in ice cores, said White, director of CU-Boulder's Institute for Arctic and Alpine Research.

"We are beginning to tease apart the sequence of abrupt climate change," said White, whose work was funded by the National Science Foundation's Office of Polar Programs. "Since such rapid climate change would challenge even the most modern societies to successfully adapt, knowing how these massive events start and evolve is one of the most pressing climate questions we need to answer."

Both dramatic warming events were preceded by decreasing Greenland dust deposition, indicating higher tropical temperatures and significantly more rain falling on the deserts of Asia at the time, said White. The team believes the ancient tropical warming caused large, rapid atmospheric changes at the equator, the intensification of the Pacific monsoon, sea-ice loss in the north Atlantic Ocean and more atmospheric heat and moisture over Greenland and much of the rest of the Northern Hemisphere.

"Here we propose a series of events beginning in the lower latitudes and leading to changes in the ocean and atmosphere that reveal for the first time the anatomy of abrupt climate change," the authors wrote. White likened the abrupt shift in the Northern Hemisphere circulation pattern to shifts in the North American jet stream as it steers storms around the continent.

"We know such events are in Earth's future, but we don't know when," said White. "One question is whether we can see the symptoms before big problems occur. Until we answer these questions, we are speeding blindly down a narrow road, hoping there are no curves ahead."

Each yearly record of ice can reveal past temperatures and precipitation levels, the content of ancient atmospheres and even evidence for the timing and magnitude of distant storms, fires and volcanic eruptions, said White. The cores from the site -- located roughly in the middle of Greenland at an elevation of about 9,850 feet -- are four-inch-diameter cylinders brought to the surface in 11.5-foot lengths, said White.

Source: University of Colorado at Boulder


TOPICS: News/Current Events
KEYWORDS: astronomy; catastrophism; climate; climatechange; clovis; clovisimpact; globalwarminghoax; godsgravesglyphs; greenland; hiawathaglacier; iceage; iceland; megafauna; science; temperature; youngerdryas
Navigation: use the links below to view more comments.
first 1-2021-4041-59 next last

1 posted on 06/19/2008 3:33:45 PM PDT by blam
[ Post Reply | Private Reply | View Replies]

To: blam

The SUVs were all the rage for those 50 years, and then, as they were outlawed to prevent global warming, the planet returned to its natural, pristine climate.


2 posted on 06/19/2008 3:37:46 PM PDT by farlander (Try not to wear milk bone underwear - it's a dog eat dog financial world)
[ Post Reply | Private Reply | To 1 | View Replies]

To: SunkenCiv
Comet Theory Collides With Clovis Research, May Explain Disappearance of Ancient People

Ice Age Ends Smashingly: Did A Comet Blow Up Over Eastern Canada? (Carolina Bays)

3 posted on 06/19/2008 3:37:50 PM PDT by blam
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Greenland Ice Core Analysis Shows Drastic Climate Change Near End Of Last Ice Age

Kinda goes without saying, doesn't it? I mean, I'd be surprised if the data said the ice age simply stopped, went away when no one was looking or something.

4 posted on 06/19/2008 3:39:41 PM PDT by NonValueAdded (If it is going to take 10 years, shouldn't we get started? Drill here, drill now, pay less.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam

Relying on one small area to cover the condition of the whole at that period...is just a big guess.


5 posted on 06/19/2008 3:43:11 PM PDT by Sacajaweau (I'm planting corn...Have to feed my car...)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Bush's Fault©
6 posted on 06/19/2008 3:44:27 PM PDT by Old Sarge (CTHULHU '08 - I won't settle for a lesser evil any longer!)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam

Can we reverse all our wind turbines into fans and change atmospheric circulation? Ooooo! Ooooo! Or we could have all our jet airliners fly against the Jet Streams and slow them down, if we have the fuel.


7 posted on 06/19/2008 3:45:24 PM PDT by Red_Devil 232 (VietVet - USMC All Ready On The Right? All Ready On The Left? All Ready On The Firing Line!)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam

This story is not true. We have been told now by the doom and gloomers that mankind causes climate change. They want us to believe there is some magical perfect “climate” that would exist if not for mankind. Without mankind, the world must have been perfection and climatically precise. Whatever could these authors be thinking?


8 posted on 06/19/2008 3:51:58 PM PDT by Sgt_Schultze
[ Post Reply | Private Reply | To 1 | View Replies]

To: Old Sarge
Bush's Fault©

The freezing or the warming?

9 posted on 06/19/2008 3:52:15 PM PDT by glorgau
[ Post Reply | Private Reply | To 6 | View Replies]

To: glorgau
Bush's Fault©
The freezing or the warming?

Yes.

10 posted on 06/19/2008 3:58:53 PM PDT by Old Sarge (CTHULHU '08 - I won't settle for a lesser evil any longer!)
[ Post Reply | Private Reply | To 9 | View Replies]

To: glorgau
Bush's Fault©

The freezing or the warming?

Both, of course!

11 posted on 06/19/2008 3:58:56 PM PDT by FrogMom
[ Post Reply | Private Reply | To 9 | View Replies]

To: blam

How did Bush cause this?


12 posted on 06/19/2008 4:00:42 PM PDT by TruthWillWin
[ Post Reply | Private Reply | To 1 | View Replies]

To: FrogMom

Just like it will no doubt be his fault that FEMA told all of the flood ravaged places that it was safe to live there because the levees would hold, in 1999.


13 posted on 06/19/2008 4:01:10 PM PDT by Blogger
[ Post Reply | Private Reply | To 11 | View Replies]

To: blam

Ya think?

duh

mrs


14 posted on 06/19/2008 4:02:08 PM PDT by proudmilitarymrs (It's not immigration, it's an invasion!)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Until we answer these questions, we are speeding blindly down a narrow road, hoping there are no curves ahead.

LOL!! Yeah, right. This guy gets wet dreams over the thought that he's going to save mankind from flying off a cliff.

15 posted on 06/19/2008 4:03:27 PM PDT by Fox_Mulder77
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
"The new findings are expected to help scientists improve existing computer models (Which are crap and have never been validated) for predicting future climate change as increasing anthropogenic greenhouse gases in the atmosphere drive up Earth's temperatures globally (except since 1998 and apparently for the next 10 to 15 years as global warming "takes a break")."
16 posted on 06/19/2008 4:05:59 PM PDT by JaguarXKE
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Yeah, nice read until you get to this lie!

The new findings are expected to help scientists improve existing computer models for predicting future climate change as increasing anthropogenic greenhouse gases in the atmosphere drive up Earth's temperatures globally.

If the facts don't fit the theory, change the facts.

17 posted on 06/19/2008 4:06:57 PM PDT by chaos_5 (Proud to be one of the 10% not rallying around McCain)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Temperatures spiked 22 degrees F in just 50 years

That sounds dramatic except that the temperature in most places spikes 22 degrees every day, and much more between summer and winter, and not much dies off from it.

18 posted on 06/19/2008 4:10:47 PM PDT by Reeses (Leftism is powered by the evil force of envy.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam

Bush’s fault.


19 posted on 06/19/2008 4:11:34 PM PDT by Hoodat (Obama's only connection to the descendants of American Slaves is that his muslim ancestors sold them)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam

The ice age ended when the temperatures rose? Gosh, these guys are brilliant.


20 posted on 06/19/2008 4:12:14 PM PDT by norwaypinesavage (Planting trees to offset carbon emissions is like drinking water to offset rising ocean levels)
[ Post Reply | Private Reply | To 1 | View Replies]


Navigation: use the links below to view more comments.
first 1-2021-4041-59 next last

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
News/Activism
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson