Balmy tropical temperatures and frost-sensitive vegetation prevailed on the coast of Antarctica 52 million years ago, according to a study of drill cores from under the seafloor off the coast of Antarctica.
Tropical vegetation, similar to what can be seen on the Queensland coast today, was growing in the area now known as Wilkes Land due south of Australia, the study has shown.
And summer temperatures in coastal Antarctica ranged between 20 and 27 degrees Celsius.
The finding, published in the science journal Nature this week, confirmed what earlier studies had indicated – that Antarctica would have been an ideal summer playground.
It also underlined the extreme contrast between modern and past climate conditions in Antarctica and the extent of global warming during periods of elevated carbon dioxide levels in the atmosphere.
The exceptionally warm period 55 to 48 million years ago was the warmest era in the Earth’s history during the past 70 million years.
The study was undertaken by an international team, led by Goethe University and the Biodiversity and Climate Research Centre in Frankfurt, Germany. The team included micro-paleontologist Dr Ian Raine of GNS Science.
Operating from the ocean drilling ship JOIDES Resolution, the scientists recovered a number of drill cores from the seabed off the coast of Wilkes Land in 2010 as part of the Integrated Ocean Drilling Programme.
The sub-seafloor rock samples were between 53 and 46 million years old and contain fossil pollen and spores that are known to originate from the Antarctic coastal region. Using this information, the researchers were able to reconstruct the local vegetation on Antarctica and deduced the presence of tropical and subtropical rainforests covering the coastal region 52 million years ago.
About 52 million years ago, the concentration of the greenhouse gas carbon dioxide in the atmosphere was more than twice as high as today.
Dr Raine said if CO2 emissions from fossil fuels continued unabated, CO2 concentrations in the atmosphere, as they existed in the distant past, were likely to be reached within a few hundred years.
Studies of warm periods in the geological past increased the knowledge of climate system mechanisms. This contributed enormously to improving our understanding of current human-induced global warming, Dr Raine said.