Sudden climatic change (scientific note)

• Main Author: Roy M. Koerner
• Format: Report
• Language: English
• Published: Geological Survey of Canada, Natural Resources Canada 2001
• Subjects: Agassiz Ice Cap; Greenland; Dansgaard-Oeschger events; Dye 3; Dye-3; GRIP; Ice cap; Ice Sheet; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2375; http://id.nii.ac.jp/1291/00002375/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2375&item_no=1&attribute_id=18&file_no=1

Studies of ice cores have shown that sudden climate changes (using δ^<18>O as a temperature proxy), were a common feature of past climate. Interplay between the Atlantic "conveyor belt"(or Thermohaline Circulation) and ice sheet melt-water is seen as the factor responsible for at least some of these sudden climatic changes. The Younger Dryas, 12.7-11.5ky BP, is a well-studied example of such an event. Dansgaard-Oeschger events may be similarly explained. More recent research has attributed a sudden cooling, registered by a δ^<18>O step in 8.2 ky old ice in the Camp Century, Dye-3,GRIP and Agassiz ice cap cores, to sudden drainage, into the Atlantic, of glacial lakes on the southern margins of the decaying Laurentide ice sheet. The question is whether a similar event could be triggered in the future by global warming and ice cap/Greenland ice sheet melt. In this paper, it is argued that all the classic sudden climatic change events occurred in the presence of the great Pleistocene Ice Sheets. It is unlikely that future melting of the northern circumpolar ice caps, glaciers and ice sheets would generate sufficient melt water to cause a similar event.