In this second of the three aspects of climate change that threaten national security, Admiral Titley discusses rising sea levels. The pace of change is gradual. The magnitude of change is small. And that allows deniers respite from reality. But the environmental effects, though local, will be catastrophic.
Glaciology combines the science of numerous disciplines. Deniers want to use simple observations of surface ice to support their conclusions. Unfortunately, it is not so simple. Ocean water is warming and with that the relationships of the glaciers to the earth on which they were grounded. Many are now afloat. We are not so certain what this means. What we know is that there is data to support the projection of a one meter sea level rise by 2100; and that is conservative.
The impact of the rise is being studied for its effects on defense infrastructure. The Department of Defense (DoD) Strategic Environmental Research and Development Panel, consisting of academics, researchers and engineers who have really studied the data are considering the impact of a sea level rise of three to three and a half millimeters per year. That pace, of course, serves those who want to eschew climate change and its effects. They are not going to wake up with seawater in their living rooms, so it is easy for them to ignore it. But it is more than the shore slipping under the water. It includes changes to local currents and how they affect both sea level rise and storm surge frequency and intensity.
So, less dramatic than open water in the Arctic Ocean, the effect of sea level rise on national security is just as significant. The DoD is invested in facilities along coasts and in estuaries worldwide. The impact on current infrastructure and future investment is enormous. Again, it is not that land will be subsumed by water under normal conditions, it includes changes to storm effects that render current sea walls and the structures they protect vulnerable. So it is not only the damage to military installations but also the population centers on coasts where the military will be deployed in the event of a natural disaster.
But the third impact of climate change, tied directly to industrialization, may be the most dramatic: Ocean water acidification.