Global climate change has doubled the risk of coastal flooding for many American communities. “Global warming has raised sea level about 8 inches since 1880, and the rate of rise is accelerating,” a new report from Climate Central found. “Scientists expect 20 to 80 more inches this century, a lot depending upon how much more heat-trapping pollution humanity puts into the sky.” While the projected range of sea level rise may leave a lot to be desired with respect to certainty, the implications of even the low- to medium-range projections (between 36-48 inches) over the next century could have dramatic consequences for the estimated 5 million Americans living at less than 4 feet above high tide, and more so for the 3.7 million living at less than 3 feet above the tide.
U.S. military planners and others in the national security community should pay attention to the study’s mid-range projections. Depending on the location, mid-range projections are estimated at 1-8 inches in sea level rise by 2030, and 4-19 inches by 2050, with some projections much higher in areas currently home to U.S. military installations. The study’s authors give projected ranges and best estimate predictions. For example, in Virginia, Sewells Point – Hampton Roads (home to Norfolk Naval Base) is projected to experience between 3-10 inches in sea level rise by 2030, and 7-24 inches by 2050, with best estimates projected at 6 inches in sea level rise by 2030, and 14 inches by 2050. In La Jolla, California (the greater San Diego region, home to Camp Pendleton to the north near Oceanside and Coronado to the south), the study projects 2-9 inches in sea level rise by 2030, and 4-22 inches rise by 2050, with best estimates projected at 5 inches by 2030 and 11 inches by 2050. The study provides a list of other communities and the projected sea level rise with 90 percent confidence intervals that are worth reviewing at length.
Although the ranges for projected sea level rise (given in inches, not feet) may seem insignificant, the risks and concerns are quite legitimate. Communities like Hampton Roads are already plagued by sea level rise and have given serious attention to adapting to the increased risk. One concern for these coastal installations is the increased risk of storm surge and the subsequent damage. Indeed, even modest sea level rise measured in single inches portends serious risks with respect to flooding. “Cities such as Norfolk have already experienced the effects of sea-level rise as powerful storms pushed water inland, leading to flooding in places where it once was rare,” The Washington Post reported last year. What is more, climate scientists project an increase in the severity and frequency of storms which may exacerbate the effects of sea level rise and the damages incurred for coastal communities, including U.S. Naval installations. The implications for military readiness cannot be overstated, and military planners need to adapt to these changes, or be prepared to reconstitute their capabilities and facilities in the wake of these events.
Beyond the challenges for the U.S. military, the security implications of sea level rise may also exacerbate challenges for agricultural production, a mainstay for some state economies, and water availability. In particular, sea level rise may have a slow, pernicious effect for agricultural communities, where even modest sea level rise can make coastal communities more saline and thus less fertile for agricultural production, particularly by intruding into ground water aquifers that reach inland. Such effects could also exacerbate other environmental trends, such as water scarcity. Many of these environmental challenges are manifesting in ways that are not yet fully understood or appreciated by those in the security community. Policymakers will need to be attentive to these issues.
In general, sea level rise is projected to be costly, more so in terms of financial costs, but potentially in loss of life if communities do not adapt to changes in the environment. The release of the Climate Central report coincides (coincidentally) with a new study by the Brookings Institution, The Year that Shook the Rich: A Review of Natural Disasters in 2011. The study is worth reading at length, but one finding jumped out at me that is worth noting in light of the new Climate Central study: “Disaster plans and defenses need to be adjusted to a new and shifting “‘normal.’” As U.S. military planners and others in the security community continue to integrate climate change into their long-term planning, this is a message that cannot be overlooked. “Once-in-a-century” disasters are likely to become more frequent – that is to say, they are the new norm. Planners must adjust their thinking and be prepared to adapt and respond to these “once-in-a-century” disasters on a more frequent basis. Many of the rare storms, for example, are becoming more frequent due to sea level rise, and security planners must be prepared to adapt to this new reality.