Ancient Global Warming Allowed Greening Of Antarctica
June 18, 2012: Ancient Antarctica was warmer and wetter than previously suspected, enough to support vegetation along its edges, according to a new study.
By examining the remnants of plant leaf wax found in sediment cores taken below the Ross Ice Shelf, scientists from the University of Southern California, Louisiana State University and NASA’s Jet Propulsion Laboratory were able to determine that summer temperatures along the Antarctic coast 15 to 20 million years ago were 20 degrees Fahrenheit (11 degrees Celsius) warmer than they are today, reaching up to about 45 degrees Fahrenheit (7 degrees Celsius); with several times more precipitation.
This occurred during a period of global warming in the middle Miocene epoch that coincided with increased levels of atmospheric carbon dioxide.
“This is some of the first evidence of just how much warmer it was,” said Sarah J. Feakins, an assistant professor of earth sciences at the USC Dornsife College of Letters, Arts and Sciences and lead author of a paper on the research published in Nature Geoscience on June 17.
Scientists began to suspect that high-latitude temperatures during the middle Miocene were warmer than previously believed when Sophie Warny, co-author of the Nature Geoscience paper, discovered large quantities of pollen and algae in sediment cores taken around Antarctica.
Fossils of plant life in Antarctica are difficult to come by because the movement of the massive ice sheets covering the landmass grinds and scrapes away the evidence. Read the full report here.
Source: University of Southern California, Newswise.