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Aug.
22, 2007 New research to test global ice volume approximately 41.6
million years ago
shows that ice caps at this time, if they existed at all, would have
been small
and easily accommodated on The findings contradict a recent controversial suggestion that
Earth was
extensively glaciated at this time despite having been much warmer than
today,
most likely because of high atmospheric carbon dioxide levels. In an
article published in Nature
on August 23, researchers using pinhead-sized fossils
(foraminifera) – collected
from sediments deep beneath the Atlantic Ocean, 380 km north of This result is more in keeping with other geological records and climate model results suggesting that the threshold for ice sheet inception would have been crossed earlier in the Southern Hemisphere than in the Northern Hemisphere because the South Pole has a continent sitting over it (Antarctica) whereas the North Pole has an ocean (the Arctic). Paul Wilson, lead proponent of ODP Expedition 207 explained,
“The beauty of
the new results is that they resolve a big problem. How can there have
been
more ice than today during an interval that was much warmer than today?
The
answer is that there was not more ice – that idea was a
mistake based on
inadequate data. The results give us renewed confidence in our
understanding of
the sequence of geological events and thus the controls on ice sheet
existence.” “The research is a classic example of the amazing
way in which the Earth
System is so intricately integrated,” said co-proponent Dick
Norris of ##
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