Earlier today, congressional Democrats held their second hearing on the national security aspects of climate change in little over a week. While it's no secret that the military has been conducting research into the implications of a warming planet for some time now, former Republican Senator John Warner confirmed in his opening statement that the Pentagon has gotten the message:

I made a further request of the Deputy Undersecretary of Defense for Strategy, Plans, and Forces, to provide me with a statement describing ongoing work in the Department of Defense. Secretary Kathleen Hicks forwarded this very interesting report:

Energy and climate change are two of the key strategic trends affecting national security. The impacts of climate change will disproportionately affect regions with limited adaptive capacity. It will contribute to food and water shortages, increase the spread of disease, and may lead to mass migration. It is going to accelerate state failure in some cases, and may also lead to the spread of insurgency as weak governments fail to cope with its effects.

Warner's remarks were seconded by Vice Admiral Dennis McGinn (Ret.), who testified before the Senate Foreign Relations Committee last week and spoke again today before the Environment and Public Works Committee. On both occasions, McGinn cited this report by the CNA Military Advisory Board, adding:

Climate change is different from traditional military threats, according to ... Vice Admiral Richard Truly, because it is not like "some hot spot we're trying to handle." "It's going to happen to every country and every person in the whole world at the same time."
... Drought and scant water have already fueled civil conflicts in global hot spots like Afghanistan, Nepal and Sudan, according to several new studies. The evidence is fairly clear that sharp downward deviations from normal rainfall in fragile societies elevate the risk of major conflict.

Add to that the current two-year drought that could lead to further instability in Iraq.

The U.S. military's transition from conventional warfare to counterterrorism has led it to wade ever deeper into areas like global aid, reconstruction, and peacekeeping duties, so an increased level of support for action on climate change makes sense. But current generals and admirals are discouraged from airing their views on anything remotely political, which is why the Military Advisory Board is made up of 11 retired generals, admirals, and vice admirals, all of whom agreed about the dire security consequences of letting global warming go unchecked.