Unusually cold water in the North Atlantic, produced by the melting of Greenland's ice, is cited as a key indicator of impending abrupt climate change on pp 9-10 of this report (PDF), "An Abrupt Climate Change Scenario and Its Implications for United States National Security," prepared for the Pentagon in 2003. The report's stated purpose was to present "a climate change scenario that although not the most likely, is plausible, and would challenge United States national security in ways that should be considered immediately."
Unusually cold water in the North Atlantic, produced by the melting of Greenland's ice, is cited as a key indicator of impending abrupt climate change on pp 9-10 of this report (PDF), "An Abrupt Climate Change Scenario and Its Implications for United States National Security," prepared for the Pentagon in 2003. The report's stated purpose was to present "a climate change scenario that although not the most likely, is plausible, and would challenge United States national security in ways that should be considered immediately."