Is climate change the biggest national security challenge we are facing?

While Tom Ricks is away from his blog, he has selected a few of his favorite posts to re-run. We will be posting a few every day until he returns. This originally ran on July 29,2011.

By Eric Hammel
Best Defense guest columnist

Over the past year, I’ve worked the vast security implications of global climate change into a few comments on The Best Defense, but they haven’t taken hold. I cannot fathom the prevailing so-what attitude as the FEMA-grade weather disasters mount toward becoming serial and routine occurrences. It’s here now, for all to see.

Tens — perhaps hundreds — of millions of heat, drought, flood, and famine refugees are probably going to be shaken loose within a decade. (Some estimates say half of humanity — 3,000,000,000 people — will have to move or die just from heat-related causes.) Thanks to topsoil erosion via drought and helped along by deadly, unstoppable tornado clusters and unlivable ambient temperatures, the bulk of farming in North America will shift northward and most likely will become restricted to a narrower band in the upper Midwest and on into higher Canadian latitudes-assuming there is sufficient rainfall there. Sea-level rise from melting glaciers on land will soon be poised to shake loose uncountable refugees from drowned coastal regions, where most of the world’s people live. If the warm North Atlantic conveyor current is halted or recedes southward due to desalinization via the Greenland freshwater ice melt, the Canadian Maritimes, New England, and northwestern Europe will probably experience unbelievable winters and might (this is counterintuitive) freeze over.

Global famine is going to force the use of our military as a police force organized to feed unknowable masses of people (until cold reality sets in as reserve food stocks evaporate). I believe that North America’s first up-close brush with famine-motivated mass migration will take place in northern Mexico and on into the U.S. border states. (Refugees fleeing in the wake of the collapse of Mexico’s central government could precede drought- and heat-related dislocations. Are we prepared to handle such a dress rehearsal?)

The only force on Earth with the inherent capability to police, process, house, feed, and move refugees on a mass scale is the U.S. military, but, though its reach is global, its capacity and stamina are nonetheless limited, probably to one or two major disasters at a time, not the overlapping rolling meta-disaster climatologists predict. (Remember, the only components of the Katrina effort that worked at all were the military responses, beginning with Coast Guard helicopters.)

The implications for military use alone in the looming weather-related crises are mind-boggling, but no one appears to want to face up to them with an action plan, a doctrine, a list of precepts. I find it worrying to the nth degree that there is absolutely no public discussion. Have the relevant agencies studied it all already-and thrown up their hands? I already know from a series of phone calls to relevant local and state agencies that there is no actual integrated plan in place to respond to high-impact earthquakes in major California population centers. The "plan" is to play it as it lays. And I sincerely doubt that a repeat of Katrina would be met with an effective plan based on lessons learned.

Can we bring this out of the shadows, and least in this venue?

Eric Hammel has written more books about the U.S. military in Vietnam, Korea and World War II than most people have read.