Climate change could lead to palm trees returning to Antarctic
Published 02/08/2012 | 02:28
Palm trees could grow in the Antarctic -- just as they did 55 million years ago -- if climate change continues unabated, new research has shown.
A study has found that similar trees grew in the region during the early Eocene epoch, when the area had a near-tropical climate with frost-free winters, even in the polar darkness.
Global levels of the principal greenhouse gas, carbon dioxide, were nearly three times as high then as today.
It has long been known that the start of the Eocene was one of the hottest periods in Earth's history, and that Antarctica as a continent would have been ice-free and much warmer than at present.
But the new findings, based on sediment cores taken from the Antarctic and disclosed today in the journal 'Nature', have enabled detailed reconstruction of its environment and thus its climate.
This was previously impossible because any Eocene sediments remaining on land were destroyed by the subsequent glaciation of Antarctica, or covered with thousands of feet of ice. But pollen grains were washed, blown or transported by insects on to the shallow coastal shelf, where they were preserved for 50 million years.
Analysis of the pollen in the sediment reveals two plant environments, one being a lowland, coastal warm rainforest similar to that in northern Australia or New Guinea.
The other was an upland, mountain forest region, further into the continent's interior, with beech trees and conifers.
Antarctica was in nearly the same position it is now, over the South Pole, so the winter months would have been dark, like today, but the presence of the flora indicates it was warmer than 10C, even during the coldest and darkest months.
(© Independent News Services)