Flying bugs trapped deep in the frozen mud covering Greenland have pointed researchers to new clues about the country’s climate, suggesting the now-icebound island was once warmer than previously believed.
In the centuries that followed the last ice age and in the millenia between the last two, Greenland could have seen summer highs between 10 and 15 degrees warmer than today, according to a new study led by researchers at Northwestern University in Illinois.
Core samples taken from the mud of a lake bed in northwestern Greenland, just beyond the edge of the ice sheet and largely undisturbed by its historical ebb and flow, revealed large numbers of preserved insects known as phantom midges and a fly species known as chironomids. Those species today usually live well south of Greenland, but the numbers found in the sediment cores taken by the Northwestern team were comparable to populations seen in the Canadian Atlantic provinces.
As far as the team could tell, the phantom midge hasn’t been seen in Greenland before now.
“We think this is the first time anyone has reported it in ancient sediments or modern lakes there," Yarrow Axford, the study's senior author, said in a statement accompanying the findings. "We were really surprised to see how far north it migrated."
The findings suggest temperatures in Greenland’s summer might have ranged into the 50s Fahrenheit, or in the low teens Celsius — well above today’s averages of around 40°F.