Study Finds
Ancient Warming Greened Antarctica
WASHINGTON
-- A new university-led study with NASA participation finds ancient Antarctica
was much warmer and wetter than previously suspected. The climate was suitable
to support substantial vegetation -- including stunted trees -- along the edges
of the frozen continent.
The team of
scientists involved in the study, published online June 17 in Nature
Geoscience, was led by Sarah J. Feakins of the University of Southern
California in Los Angeles, and included researchers from NASA's Jet Propulsion
Laboratory in Pasadena, Calif., and Louisiana State University in Baton Rouge.
By
examining plant leaf wax remnants in sediment core samples taken from beneath
the Ross Ice Shelf, the research team found summer temperatures along the
Antarctic coast 15 to 20 million years ago were 20 degrees Fahrenheit (11
degrees Celsius) warmer than today, with temperatures reaching as high as 45
degrees Fahrenheit (7 degrees Celsius). Precipitation levels also were found to
be several times higher than today.
"The
ultimate goal of the study was to better understand what the future of climate
change may look like," said Feakins, an assistant professor of Earth
sciences at the USC Dornsife College of Letters, Arts and Sciences. "Just
as history has a lot to teach us about the future, so does past climate. 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."
Scientists
began to suspect that high-latitude temperatures during the middle Miocene
epoch were warmer than previously believed when co-author Sophie Warny,
assistant professor at LSU, 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 more:
see also:
“Hydrologic cycling over Antarctica during the
middle Miocene warming”
photograph: