I've often joked that in Washington, if you attach the word "security" to anything, it automatically becomes important. Thus we have our climate change and energy bills given names like the Energy Independence and Security Act or the American Clean Energy and Security Act. But in fact, framing the climate crisis as a security issue is both substantively grounded and appears to have some promise as a way to persuade fence-sitters in Congress on climate legislation, as this NYT editorial argues.
In one sense, this should be intuitive: If you subject the earth's climate to unprecedented levels of stress, the results (e.g., drought, flooding, infectious disease) will be bad for governments around the world, and especially bad for governments that are weak, unstable, or corrupt, and thus ill-equipped to handle these problems. For example, on top of all the other problems Pakistan is facing, it's also dealing with a growing water crisis -- one that will likely intensify as the glaciers in the Himalayas disappear. Even stable governments could fall apart if the scale of the calamity is big enough: If the ocean rises over the dikes of the Netherlands, the country could go from a modern industrialized democracy to a failed state in the blink of an eye.
The main point of contention, I think, has less to do with the strength of the link between climate change and national security, and more with defining what constitutes "national security," regardless of what connection it has to climate change. We just lived through an era in which the term was defined almost exclusively in terms of what could be accomplished in terms of men with guns and bombs, and needless to say, it was a disaster.* Even if we define national security in broader terms, however -- promoting stable governance, respect for human rights, etc. -- we must still recognize that for all of our wealth, we're not omnipotent: if there's one thing we've learned since 9/11, it's that we have much less leverage over other countries, even very poor countries, than we think we do. There seems to be very little the US can do about failed states like Somalia or repressive states like Burma, short of armed force -- which, as I just mentioned, often creates more problems than it solves.
Why focus on this? Because I think this points to the need to have the question of "climate security" embedded in the larger ethical framework that has grown up around climate change (e.g., that old standby, common but differentiated responsibility). It's well established, at least for many, that the developed world should take primary responsibility for dealing with the effects of climate change, especially in the developing world. Usually this means some kind of technology transfer or financial assistance, but I think it also should mean helping governments in vulnerable parts of the world become more resilient in the face of climate-related upheavals. This is where the recommendations in Paul Collier's The Bottom Billion, for example, could be useful. And of course, it also means the developed countries should make reducing carbon emissions a top priority.
* The Obama administration is turning this mindset around, of course, yet it still persists: The Obama policy on Afghanistan, for example, seems to emphasize putting more troops on the ground, but not on defining realistic, achievable goals for what can accomplished in terms of a US occupation. See Matt Yglesias for more on this.