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The Tenacity of Greenland Ice
Volume 10, Number 12: 21 March 2007

To hear Al Gore and his acolytes talk nowadays, one would think the Greenland Ice Sheet was teetering on the verge of extinction, melting rapidly and all but "slip-sliding away" into the ocean, where its water would raise global sea levels to heights that would radically alter continental coastlines and submerge major cities. However, the recent study of Eldrett et al. (2007), which was published in the 8 March 2007 issue of Nature, provides important new evidence that suggests Mr. Gore's view of the matter may well be poles away from the truth.

The five researchers from the School of Ocean and Earth Science of the National Oceanography Centre of the University of Southampton in the UK report they "have generated a new stratigraphy for three key Deep Sea Drilling Project/Ocean Drilling Program sites by calibrating dinocyst events to the geomagnetic polarity timescale." In doing so, they say their detailed core observations revealed evidence for "extensive ice-rafted debris, including macroscopic dropstones, in late Eocene to early Oligocene sediments from the Norwegian-Greenland Sea that were deposited between about 38 and 30 million years ago." They further report that their data "indicate sediment rafting by glacial ice, rather than sea ice, and point to East Greenland as the likely source," and they conclude that their data thus suggest "the existence of (at least) isolated glaciers on Greenland about 20 million years earlier than previously documented."

What is particularly interesting about this finding, as Eldrett et al. describe it, is that it indicates the presence of glacial ice on Greenland "at a time when temperatures and atmospheric carbon dioxide concentrations were substantially higher." How much higher? According to graphs the researchers present, ocean bottom-water temperatures were 5-8C warmer, while atmospheric CO2 concentrations were as much as four times greater than they are today.

The problem these observations provide for Mr. Gore, to quote Eldrett et al., is that "palaeoclimate model experiments generate substantial ice sheets in the Northern Hemisphere for the Eocene only in runs where carbon dioxide levels are lower (approaching the pre-anthropogenic level) than suggested by proxy records," which records indicate atmospheric CO2 concentrations fully two to seven times greater than the pre-anthropogenic level during the time of the newly-detected ice sheets.

"Regardless," as the researchers continue, "our data provide the first stratigraphically extensive evidence for the existence of continental ice in the Northern Hemisphere during the Palaeogene," which "is about 20 million years earlier than previously documented, at a time when global deep water temperatures and, by extension, surface water temperatures at high latitude, were much warmer."

Therefore, and also "by extension," there is great reason to not only doubt, but to reject out-of-hand, Mr. Gore's scare stories of sea levels rapidly rising tens of feet in response to his implied rapid demise of the Greenland Ice Sheet, which he sees as occurring in response to a warming of the planet that may be pushing it perilously close to a high-temperature "tipping point," for we now have evidence of a much warmer period of time that failed to bring about such a catastrophic consequence.

Sherwood, Keith and Craig Idso

Reference
Eldrett, J.S., Harding, I.C., Wilson, P.A., Butler, E. and Roberts, A.P. 2007. Continental ice in Greenland during the Eocene and Oligocene. Nature 446: 176-179.