Econintersect: The ice melt in Greenland has reached a modern high level in the summer of 2012, according to NASA. The giant Petermann Glacier produced a giant calf for the second time in two years (2010 and 2012). The extent of melt seen this summer was last experienced in 1889. The expansion of the area melting grew from 40% to 97% of the ice sheet in just four days from July 8 to the 12th. NASA scientists described the rapidity of the expansion as “extraordinary”. On the other hand, Fox News reports that skeptics say the concern about the melting event is unwarranted. These skeptics cite that this event occurs regularly, once approximately every 150 years, on average.
Click on photo for large scenery view of Greenland village.
As sudden as this summer’s ice melt phenomenon may seem, it is part of a progression of events that has been occurring for decades. The following graph from EEA (European Environmental Agency) shows the progression of ice melting for the 30 years 1978-2008.
The following graph shows that as recently as 2003-2005 the net change in ice mass of Greenland has been positive, but the very short-term has been sharply toward increasing ice mass loss.
The EEA has published estimates of what temperature changes would be necessary to trigger certain major climate/geological effects for the planet. The temperature changes reference 1990.
The global temperature change since 1990 is approximately +0.50C, according to the data published by Hansen (see second graph below). A smaller estimate (0.2-0.30C) is obtained from the graph below.
Click on graphic for larger image.
The following graph is from the GEI image files (source unknown).
This gives some perspective of the estimated temperature changes over the past two millennia. The following graphic by Hansen shows the temperature rebound from the mini ice age over the past two centuries.
Click on graph for larger image.
But when one looks at short time periods, as in the following graph from the Daily Mail, temperature changes may not be evident.
The Daily Mail article discusses the viewpoint that the sun spot cycle could dominate earth’s weather and we could be going back into a mini ice age based on that.
If Greenland really is going to continue warming, it has a way yet to go to return to the climate and landscape found there by Norse explorers and settlers a thousand years ago. There were extensive land areas settled as shown in the following graphic from Archaeology:
The Viking settlements reached a population of 5,000 or more and remained for about 450 years before they disappeared after losing contact with their Scandinavian ancestral homeland, due to many factors but most probably primarily the Black Death devastation of Europe in the latter part of the 14th century and the increasing hazard to navigation from increased ice flows as the climate cooled.
When the Vikings arrived in Greenland in 980 AD they found evidence of earlier inhabitants, known as the Dorset people, an advanced Paleo-Eskimo culture that flourished from 500 AD to the 6th or 7th centuries AD, but then went into decline and vanished completely between 1200 and 1500 AD.
The Inuit started settling Greenland in the 1200s just as the climate was cooling and the Vikings were nearing the end of their settlement period. The Inuit constitute 88% of the 56,000 inhabitants of Greenland today. Most of the remaining population is Danish.
A paper posted by the Indiana University Purdue University Indianapolis website has the following five possibilities for how and why the Vikings disappeared from Greenland:
Killed off by the Inuit. The Vikings were aggressively hostile to native peoples.
Loss of contact with Europe. Inability of survive without supplies from Norway.
Poor horticulture. Farming methods depleted the soil and caused destructive erosion.
Climate change. Global cooling made the harsh Greenland environment even more challenging.
Failure to adapt to local food sources. There are indications of severe malnutrition because the Vikings didn’t eat the abundant marine life available.
Another possibility that has been in North American folklore for centuries is that the remaining Vikings migrated to North America and became absorbed in the native populations there. There is little scientific evidence that happened, but the folklore from early explorers and from the native oral history have both presented material which could be consistent with such an occurrence. And the oral and written history of the Vikings on Greenland contained the record of eleventh century Viking settlements that have recently been unearthed in Newfoundland, so the remnant population on Greenland definitely would have known of the escape route to the west.
Back to modern day Greenland, live through a dangerous glacier calving experience in the following MSN video. Click on image to view.
Sources:
- Huge glacier calves off Greenland (Discover Magazine)
- Satellites reveal sudden Greenland ice melt (BBC, 25 July 2012)
- NASA: Strange and sudden massive melt in Greenland (Seth Borentstein, Associated Press, 24 July 2012)
- Skeptics put the freeze on NASA ‘hot air’ about Greenland ice/ (Jeremy Kaplan, Fox News, 26 July 2012)
- Melting area 1979-2008 and mass change 2003-2009 of the Greenland ice sheet (EEA, 12 January 2011)
- Estimated global warming at which the onset of the events could occur versus their impact (EEA, 17 February 2012)
- Forget global warming – it’s Cycle 25 we need to worry about (and if NASA scientists are right the Thames will be freezing over again) David Rose, Daily Mail, 29 January 2012)
- The Fate of Greenland’s Vikings (Dale Mackenzie Brown, Archaeology, 28 February 2000)
- The Dorset People (Canadian Museum of Civilization)
- History of East Greenland (East Greenland Website)
- Greenland (Wikipedia)
- 600-Year Old American Indian Historical Account Has Old Norse Words (Larry Stroud, Free Republic, 15 March 2007)