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article imageDNA Discovery Shows Greenland's Warm Past, Altering Thoughts on Climate Change

Posted Jul 8, 2007 by  Chris Hogg in Science | 9 comments | 2274 views
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In more research to further confuse everyone in the global warming debate, scientists have found what is believed to be the oldest authenticated DNA evidence ever recorded, showing Greenland was once much warmer than previously thought.

Digital Journal -- According to new DNA evidence, scientists say the southern tip of Greenland was once covered in lush forests and had a vast population of pants and insect life.

The evidence was found after researchers analyzed DNA found from ice core drilling to a depth of 2-3 km (about 1.5 miles). Dating back 450,000 to 800,000 years ago, the evidence of life has scientists now saying ice sheets in the region could be more stable against climate change than initially thought.

"We have shown for the first time that southern Greenland, which is currently hidden under more than 2km of ice, was once very different to the Greenland we see today," Eske Willerslev, a biologist from the University of Copenhagen said in a press release."Back then, it was inhabited by a diverse array of conifer trees and insects."

Willerslev told Scientific American fossils hidden below ice cover about 10 per cent of the Earth's surface but DNA is difficult to extract because it's buried so deep.

Drilling techniques have come a long way recently, allowing Willerslev and his colleagues to reach greater depths. Writing in the journal Science, Willerslev said his research sampled basal ice — soil trapped at underneath ice sheets — that holds biological material, providing more DNA evidence of past climates.

The researchers have so far found evidence of plants, pine, spruce and alder trees, insect life such as beetles, flies, spiders, butterflies and moths dating back as far as 800,000 years.

One of the most interesting aspects of this finding is how it could change the global warming debate. This research shows forests and life inhabited southern Greenland during the interglacial period (116,000-130,000 years ago) when the Earth saw increased global temperatures five degrees Celsius warmer than today.

This research shows the area was covered in ice once the temperature dropped. This is contrary to what scientists have always believed about the area around Greenland.

"If our data is correct, then this means that the southern Greenland ice cap is more stable than previously thought," Willerslev said. "This may have implications for how the ice sheets respond to global warming."

Professor Dorthe Dahl-Jensen, also at the University of Copenhagen, said the warming temperatures back then would have reduced the ice between 1 to 1.5 km (almost one mile).

Willerslev also said: "We know that during the last interglacial, sea levels rose by 5-6m, but this must have come from other sources additional to the Greenland ice cap, such as Antarctic ice. I would anticipate that as the Earth warms from man-made climate change, these sources would still contribute to a rise in sea levels."
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  • avatar Posted Jul 8, 2007 by  Bob Ewing
    #1
    There should be little doubt that there are natural climate change cycles and this evidence seems to support that. It does not refute or even challenge the concept that human activity, of all kinds, has an impact on these natural cycles which is or should be the core of any discussion on global climate change.
  • avatar Posted Jul 8, 2007 by  Chris Hogg
    #2
    @ Bob Ewing
    There should be little doubt that there are natural climate change cycles and this evidence seems to support that. It does not refute or even challenge the concept that human activity, of all kinds, has an impact on these natural cycles which is or should be the core of any discussion on global climate change.

    Indeed it does not address human impact. However it is interesting to see how science can evolve based on technology and a finding like insects and trees can lead to new theories on how stable the earth is.

    Global warming has scared the pants off so many people around the world, so I thought it was very interesting to see a case in history where it mirrored today's world yet recovered naturally.

    In my opinion, humans are playing with the Earth's ability to do that, but interesting nevertheless.
  • avatar Posted Jul 8, 2007 by  Bob Ewing
    #3
    However it is interesting to see how science can evolve based on technology and a finding like insects and trees can lead to new theories on how stable the earth is.
    I do find this fascinating.
  • avatar Posted Jul 8, 2007 by  Debra Myers (skyangel)
    #4
    Very interesting post, Chris!

    I had seen this the other day but didn't take the time to read it through...I hope that the scientists are right, and the whole ice cap will not completely melt off.
  • avatar Posted Jul 8, 2007 by  Theodora L. (Franklin)
    #5
    In my opinion, this is just the beginning of a new era, in which scientists will dispute the so-called facts that were made in the past. It seems like many things we thought were right about the Earth and/or certain parts of it are coming out as wrong.

    To make things even more complicated, recently scientists found out that the Earth is smaller than we thought it was bringing a totally new way of measuring longitudes and latitudes. But for so many years, we thought that the exact measurements of the Earth are correct.

    I wonder what is next on the list of disputable science "facts".
  • avatar Posted Jul 8, 2007 by  Bob Ewing
    #6
    Consider facts to be fluid and experts capable of being wrong and you are moving in the correct direction.
  • avatar Posted Jul 8, 2007 by  MR
    #7
    great Find!
  • avatar Posted Jul 10, 2007 by  Bart B. Van Bockstaele
    #8
    This is indeed an important finding, especially because it is a very good indication -even to the layperson- of the fact that current climate models (used to "prove" human-caused global warming) are nothing more than the result of guesswork based on very fragmentary information.

    I tried to combine the article with another one, but that doesn't seem to work, so I put the link here:

    [url=http://www.digitaljournal.com/article/203398/DNA_on_Greenland_and_what_about_global_warming_]http://www.digitaljournal.com/article/203398/DNA_on_Greenland_and_what_about_global_warming_
  • avatar Posted Jul 10, 2007 by  Bart B. Van Bockstaele
    #9
    @ Bob Ewing
    It does not refute or even challenge the concept that human activity, of all kinds, has an impact on these natural cycles which is or should be the core of any discussion on global climate change.

    Indeed. But it *does* refute and challenge the concept that current climate models are correct. They are not, and they can't be.

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