“We are positive that these forests must have been teeming with animals; many of the pollen grains that we found were from flowering plants that were insect-pollinated,” said palaeo-climatologist Jörg Pross.
In a study published in the current edition of science journal Nature, researchers from Pross' Goethe University and the Biodiversity and Climate Research Centre in Frankfurt report how rock samples from drill probes off the coast of Wilkes Land, Antarctica, contained evidence that a period of intense warmness had occurred around 52 million years ago.
They first dropped a line four kilometres into the water to reach the seabed, then drilled another kilometre down into the sediment. The interval corresponding to 52 million years ago was encountered at 980 metres below the sea floor.
During that period the concentration of the greenhouse gas carbon dioxide (CO2) in the atmosphere was more than double what it is today, and warmth-loving plants such as palms and the ancestors of today’s baobab trees flourished.
"It was a really bizarre feeling," said Pross, who spent two and a half months on the drill ship surrounded by icebergs, "seeing the Antarctic ice shield looming in the background - and realizing that we had travelled back 52 million years in time."
That period of warmness was primarily caused by gases from volcanoes, Pross said. But scientists hope that studying naturally-occurring climate warm periods in the geological past will help improve our knowledge of current human-induced global warming.
At this point, the future does not look too rosy.
“If the current CO2 emissions continue unabated due to the burning of fossil fuels, [high] CO2 concentrations in the atmosphere - as they existed in the distant past - are likely to be achieved within a few hundred years,” Pross said.
Northern Germany could be subtropical in a couple hundred years. But Pross said the rise in global temperature would eventually melt the polar ice caps, causing sea levels to rise.
"At that point most of Northern Germany would be underwater."
But there's no need to build a boat just yet - Pross says that's likely still thousands of years away. In the meantime, climatologists stress the importance of cutting fossil fuel output to put the brakes on Antarctica becoming a sunny holiday destination.