Scientists Find Evidence of Global Warming Eons Ago
By Jessica Berman
Environmental scientists gathering data at
the North Pole say the climate was so warm 55 million years ago as a
result of greenhouse gases, it was possible to swim in the Arctic
Ocean. The researchers say the findings provide a window into the
future.
An international team of scientists made the discovery about the
earth's climate 55 million years ago from sea core samples they
gathered during an expedition to the North Pole in 2004.
Researchers say the average temperature at the North Pole back then
was 24 degrees Celsius. "It was extremely nice for a swim," said Appy
Sluijs. "It's warmer than the present North Sea, for example." Appy Sluijs of the University of Utrecht in the
Netherlands is an author of one of several papers on the expedition
that appears in the journal Nature.
Fifty five million years ago, experts say, there was a huge release
of a greenhouse gas, possibly methane or carbon dioxide, into the
atmosphere. The gas may have been in a deposit in the ocean floor,
probably until it was disturbed by a massive geological event ,such as
an earthquake.
The result, says Sluijs, was global warming. Researchers found
supporting evidence embedded in the Arctic core samples in the form of
a tiny algae called dinoflagellates.
"We know for this time interval what type of species were living in
the tropics and what kind of species were living on the higher
latitudes," said the Dutch scientist. "And now it appears this specific
tropical dinoflagellates, this algae, migrated all the way up through the North Pole into the Arctic Ocean."
Researchers also found evidence suggesting there was an abrupt cooling off period on earth.
In a separate paper, Kate Moran of the University of Rhode Island
describes how her team found a large pebble in an ice core dating back
to 45 million years ago.
"And in order to move something like from land to that part of the
ocean, you need to transport it with something that can float and
move," said Kate Moran. "And the only way we thing it could have gotten
there was from ice. And so what we are suggesting we think the ocean
basin started to freeze at that time forming sea ice, perhaps icebergs.
And that is much, much earlier than anyone ever thought, that the
northern hemisphere actually began to cool."
The researchers say their finding is a good indication of what
happens if similar concentrations of greenhouse gases are pumped into
the atmosphere in the next few hundred years.
10:46:27 PM 
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