Earlier this week, the Guardian printed a long, in-depth report by Patrick Barkham from Greenland. The arctic is the front-line of climate change: what happens there in the next decade will point the direction that the world is heading. Barkham's article makes clear that we're heading in a dangerous direction.
When it released its most recent report in 2007, the IPPC did not include predictions about the fate of the ice sheets, because they were too little understood, and too complex. That was a mistake, but researchers are working to learn more. We need to understand how this complex system works, so that we can best predict the consequences of warming in the arctic.
The glaciers of Greenland are not a direct security challenge: there will be no military engagements over newly openned land in Greenland. However, they are a harbinger of the security challenges which we will face. If the Greenland ice sheet does melt entirely, that will raise global sea levels by 7 meters. At this point, nobody's predicting that the entire sheet (2 miles thick at points) will melt, but as noted in the article, its only the first meter that counts. That first meter will put the homes and places of work of 10% of the world's population at risk. Our major cities -- London, New York, Shanghai, Mumbai -- will require massive flood protection systems to keep the tides back. Some will be overwhelmed. This is a threat to our security, and it must be addressed.