Growing concern among U.S. military and intelligence analysts about the dire strategic threat that climate change poses to the nation's security must be part of the debate next month when the Senate takes up the energy bill passed by the House.

Adding national security to the compelling arguments for reducing carbon emissions and developing alternative energy sources is not merely prudent. It may help depoliticize the issue of climate change. Opponents of the theory of human-caused global warming who are unconvinced by rapidly melting polar ice might take notice of the fact that the Pentagon is including the effects of climate change in its war games.

The National Intelligence Council concluded last year that droughts, storms, and shrinking coastlines would usher in a nightmare of destabilizing poverty, hunger, mass migration and other crises that could weaken or topple governments and create enormous humanitarian challenges for the United States. Responding to those challenges would heavily burden the military, "resulting in a strained readiness posture and decreased strategic depth for combat operations."

Some concerns are immediate. With the summer Arctic ice cap shrinking to perhaps its lowest minimum this year (the lowest was in 2007), and with the normally impassable Northwest Passage relatively free of ice the past two summers, the military must expend more resources defending shipping traffic above and staking out prized natural resources below.

It is probably unlikely that the national security argument that backers of the energy bill are beginning to make will sway senators from coal- and oil-producing states who oppose a carbon cap-and-trade system as an unnecessary economic hardship. But what of others with strong positions on national security? Hard to say.

But there is a choice to be made, sooner than later, as retired Gen. Anthony C. Zinni recently wrote in a report for the Navy quoted by The New York Times: "We will pay to reduce greenhouse gas omissions today, and we'll have to take an economic hit of some kind. Or we will pay the price later in military terms. And that will involve human lives."