Though I know that any question about Global Warming generally sparks a debate I’m hoping for GQ style answers here. My question has to do with retreating ice at the poles, especially the North Pole, and in Greenland. I was reading an article earlier and they were taking about the Arctic region being ice free sometime in my lifetime. What I’d like to see is a chart or graph showing the recession of ice there for as long as we have been recording such things (if such a chart or graph exists).
Also, I have a question about Greenland wrt Global Warming. Greenland’s ice sheet is melting as well of course, so my question has to do with the early Viking settlements on Greenland. How different are conditions today on Greenland to how they were at the height of the Viking settlements? Is there more open land (i.e. less covered in ice) today and is it more habitable today than it was then? Are temperatures higher today on Greenland than they were then?
Between the first settlements in Greenland in 986 and the early 1200s, the climate seems to have been relatively warm, conducive to boreal farming, along parts of both coasts, there being settlements along the southern parts of both east and west coasts. Climate began getting worse in the 1200s, and Greenland Eskimos moved south, displacing the Western Settlement by 1340. By 1250 sea ice made reaching the Eastern Settlement hazardous, and worsening climate and advancing ice appears to have done it in, though it seems to have kept a toehold until nearly 1500. (Source:Gwyn Jones, A History of the Vikings, Oxford U. Press, pp. 292-311).
Speculation: By digging up deep layers of Ice or hard packed snow (that was thought to have been layed down at that time) and chemically examining them.
Further explanation of specualtion: For example, they can measure ice movement inside a glacier, and speculate that the ice at the “x” foot layer was formed in 1870. Bore it out, and chemically examine the sample to see the environmental conditions in which it formed.
You can examine scratch marks on rocks to see the movement of ice in the past. (Like tide lines. Heh.)
Well, rather than hanging around dictionaries (boring!), I followed the link to the data to see if there was any information attached about where it came from … Lo and behold!
The University of Illinois’s Arctic Climate Research Center recently released a study of global sea ice levels (on average) are the same as they were in 1979, the year global satellite data gathering was begun. This is “floating” ice, not Greenland glaciers and such, but it does include the North Pole, which saw a significant rebound in the latter half of 2008 with regards to ice coverage, according to this article This rebound was attributed (by one of the researchers) to colder temperatures, less wind, and less snow cover.
They are overjoyed in Greenland, since they are already now starting to be able to farm their own vegetables, fruit and berries. It’s part of the official Greenlandic future strategy to take advantage of this in the future.
:shrug: I have no reason to believe that Tkachuck misrepresented anything with his graph, which is apparently adapted from a 1977 work by Hubert H. Lamb. William Connelly apparently says that Lamb was eminent in his field.
If you want to debate the contents of the Tkachuck paper, feel free to open a thread in the debate forum.
