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New Evidence Points To Tropical Times For Antarctic During Eocene Epoch

August 2, 2012
Image Credit: Photos.com

Brett Smith for redOrbit.com – Your Universe Online

As the world´s greatest athletes compete for gold, silver, and bronze in London, new scientific evidence suggests that future summer Olympics could be hosted in a more remote location: Antarctica.

An international team of climate scientists has discovered 50 million-year-old fossilized pollen in the seabed off the eastern coast of the polar continent, according to their report published this week in the journal Nature.

The discovery opened a window into the climate of the Eocene epoch, when temperatures around Antarctica were between 65 and 70 degrees Fahrenheit in the summer months and atmospheric carbon dioxide levels were over twice as high as today. Scientists said the Antarctic winters would have had extended periods of darkness like today, but with much warmer temperatures.

Although the polar temperatures were much higher during the Eocene, evidence points to a temperature gradient from pole to equator that was much smaller than modern times.

According to the study, this latest discovery could also give us a glimpse into future Earth climates if atmospheric greenhouse gas concentrations were to continue to rise.

“Recently the early Eocene has received considerable interest because it may provide insight into the response of Earth´s climate and biosphere to the high atmospheric carbon dioxide levels that are expected in the near future as a consequence of unabated anthropogenic carbon emissions,” the authors wrote.

The research itself is groundbreaking because the level of detail provided by the sediment analysis was previously impossible. Any Eocene sediment that might be found on land was either destroyed by the advance of Antarctic glaciers 34 million years ago or still covered with thousands of feet of ice.

Study co-author James Bendle of the University of Glasgow emphasized the difficulty in obtaining the samples and also the reward associated with taking a glimpse into what some scientists have called the ‘Greenhouse World’.

“The Eocene sediment samples are the first detailed evidence we have of what was happening on the Antarctic during this vitally important time,” he said.

“We conducted the drilling expedition against a backdrop of freezing temperatures, huge ocean swells, calving glaciers, snow-covered mountains and icebergs. It´s amazing to imagine a time-traveler, arriving at the same coastline in the early Eocene, could paddle in pleasantly warm waters lapping at a lush forest.”

Bendle went on to warn that the trends in greenhouse gas emissions could put the world back to a climate somewhat resembling the Eocene, with tropical and subtropical environments subsisting from 0 to around 70 latitude, both north and south of the equator.

“Our work carries a sobering message, he said. “Carbon dioxide levels were naturally high in the early Eocene, but today CO2 levels are rising rapidly through human combustion of fossil fuels and deforestation. We haven´t reached Eocene levels yet, but we are increasing at a rate faster than anytime in Earth´s history.”

“Atmospherically speaking we are heading rapidly back in time towards the Eocene. Already CO2 levels are at a peak not seen since the Pliocene warm period 3.5 million years ago. The biggest threat lies in the fact that Antarctica today is covered with ice, enough to potentially raise global sea-levels by 60 meters if the continent once again reaches Eocene temperatures, which would have devastating effects all over the world.”


Source: Brett Smith for redOrbit.com - Your Universe Online



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