Yesterday, the US Department of the Interior released a report that details the consequences of sea level rise for the US National Parks System. When all the assets within a meter of sea level are considered, the report estimates that about $40 billion in our national heritage may be at risk.

Although there are a number of official parks that border the sea, the National Park Service is also responsible for things like national recreation areas and national historic sites. Thus, in addition to basic infrastructure at these locations, assets include things like historic buildings and the Statue of Liberty. In total, 118 of these sites are in close proximity to the ocean, putting them at risk of damage from future sea level rise; this initial report looked at 40 of these.

Under business-as-usual emissions, the IPCC estimates that sea level could rise by roughly a meter by the end of this century, driven by melting ice and thermal expansion of the oceans. So the National Parks Service took a database of its major assets and figured out how far they were above the present sea level; anything within a meter was considered at risk. The value of these assets was then totaled, giving the $40 billion figure. Hurricane Sandy's impact on New York City facilities was then used to validate that the estimates were reasonable.

Obviously, as the remaining locations are analyzed, that number is likely to go up. If the remaining sites are anything like the existing ones, the total at risk will easily clear $100 billion. And beyond the financial value of things like sea walls and roads, we run the risk of losing unique historic sites.