Nature Geoscience, the examination of the leaf wax remaining in sediment core samples taken from beneath the Ross Ice Shelf enables the scientists to estimate the summer temperature of the area in ancient time.
They found that summer temperatures along the Antarctic coast some 15 to 20 million years ago had been 20 degrees Fahrenheit (11 degrees Celsius) warmer than that today. The precipitation levels had also been several times higher than the current measures.
"The ultimate goal of the study was to better understand what the future of climate change may look like," said Feakins, adding, “this record shows us how much warmer and wetter it can get around the Antarctic ice sheet as the climate system heats up. This is some of the first evidence of just how much warmer it was."
The peak of this Antarctic greening occurred during the middle Miocene period, between 16.4 and 15.7 million years ago. The date estimated to be after the age of the dinosaurs, which became extinct 64 million years ago, the researchers clarified.
During the Miocene epoch, mostly modern-looking animals appeared on Earth, such as three-toed horses, deer, camel and various species of apes. This comes while modern humans did not step on the planet until 200,000 years ago.
Meanwhile, warm conditions during the middle Miocene are believed to be associated with carbon dioxide levels of around 400 to 600 parts per million.
High carbon dioxide levels during the middle Miocene epoch have been documented through multiple lines of evidence including the number of microscopic pores on the surface of plant leaves and geochemical evidence from soils and marine organisms, as well.
New research indicates that the ancient Antarctica had been much warmer and wetter during the middle Miocene epoch than was previously believed.
A team of scientists led by Sarah J. Feakins of the University of Southern California in Los Angeles in collaboration with NASA's scientists and Louisiana State University researchers unraveled that the climate of the ancient Antarctica had been suitable for the then vegetation such as stunted trees along the edges of the frozen continent.
According to the paper published in