I was forwarded a slide show presentation done by Thomas Lowell et al of the University of Cincinnati titled: Organic Remains from the Istorvet Ice Cap, Liverpool Land, East Greenland: A Record of Late Holocene Climate Change
It was presented last week at AGU’s Greenland Climate Change Past and Present session. It has some very interesting data in it. In summary it has a report on occurrence of subfossil organic remains, with organics recovered in locations presently void of plant growth.
Picture of Istorvet organic remnants at edge of glacier melt.
The preliminary conclusion from the data collected in the field work is that presently the small ice caps at high latitudes in Greenland are retracting to locations where they were at 1000 years ago. The presence of subfossil vegetation was found within 280 vertical meters of ice cap summit and where comparable modern assemblages do not exist. The implication seems to be that there were warmer periods in these areas prior to today, warm enough for plant growth.
According to the study, the organic material in Liverpool Land radiocarbon dates from 400 to 1015 AD. It is interesting to note that the Vikings settled in Greenland around 974 AD and the study indicates that ice cap expansion began around 1015 AD.
While the UC team that did the field work still has more work to do to reconstruct temperatures from this data, the study lends support to the idea that Greenland’s climate was warmer approximately 1000 years ago. One of the organic samples recovered at another location was dated to 910BC. This makes one wonder just how often shifts in Greenland’s climate occurs.
More study is needed, but this is certainly interesting. You can view the abstract here