Arctic was ice free-Palm trees grew in Arctic, Reuters, Nature Geoscience

10/26/09, Reuters:

• Clouds, volcanic eruptions cited. Contradicts currently touted "computer models.'
  

"Palms flourished in the Arctic during a brief sweltering period about 50 million years ago, according to a study that hints at

• gaps in our understanding of modern climate change.

The Arctic "would have looked very similar to the vegetation we now see in Florida," says Dr Appy Sluijs of Utrecht University in the Netherlands who led the international study. Evidence of palms has never been found so far north before.

• The scientists, sampling sediments on a ridge on the seabed about 500 kilometres from the North Pole and up to 53.5 million years old,
  
• found pollen from ancient palms as well as of conifers, oaks, pecans and other trees."...

The findings were published "in the journal Nature Geoscience.

• (continuing): "That contradicts computer model simulations, also used to predict future temperatures,
  

that suggest winter temperatures were below freezing even in the unexplained hothouse period that lasted between 50,000 and 200,000 years ago during the Eocene epoch....

• The scientists say the presence of palms... hinted that the
  
• modern climate system could yield big surprises....

• One possibility for the ancient spike in temperatures was an abrupt rise in carbon dioxide levels, far beyond current concentrations.

• That might have been caused by volcanic eruptions, or a melt of frozen methane trapped in the seabed.

"We cannot explain this with the current knowledge of the climate system," says Sluijs. One possibility was that new types of clouds formed in the Arctic as it warmed, acting as a blanket that trapped ever more heat and accelerated warming....

• Such effects caused by new cloud formation could be an unexpected tripwire in accelerating modern climate change."

"Palms once grew in ice-free arctic," Reuters by Alister Doyle published in Australian Broadcasting Corporation News in Science, 10/26/09. photo from ABC.Au Science website, stock.xchange