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

article:204026:17::0
By Chris Hogg     Jul 8, 2007 in Science
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."
article:204026:17::0
More about Dna, Greenland, Global warming
 
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