The 400-meter decrease in thickness at the NEEM site reported by the scientists, for example, included a range of plus or minus 250 meters. The finding that the surface elevation was 130 meters below the present included a range of plus or minus 300 meters.
"I don't think they should have reached any conclusion about how much the ice sheet shrank," added Kurt Cuffey, a professor at the University of California, Berkeley, noting the "uncertainties" in the number ranges. The high end of the range for reduction in ice thickness is "very large," he said.
Additionally, Greenland still will be the biggest contributor to sea level rise in the immediate future, despite Antarctica's ultimate role, according to Dahl-Jensen. A study in November in Science found that Greenland has experienced more dramatic melting than Antarctica since the 1990s (ClimateWire, Nov. 30, 2012).
Dahl-Jensen noted that a fraction of the sea level rise seen in the Eemian, 1 meter, would still create major problems for coastal areas. Many scientists think that 1 meter (3.2 feet) of global sea level rise is possible by 2100.
The ice core also revealed significant surface melting of the Greenland ice sheet during the Eemian, just as there was in 2012, when it rained near the study site. This dynamic of intense surface melting will continue as the Arctic heats up faster than the rest of the globe, said Dahl-Jensen.
"The present warming over Greenland make surface melt more likely, and the predicted warming over Greenland in the next 50 to 100 years will very likely be so strong that we will potentially have Eemian-like climate conditions," she said.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500