2008. The value of coastal wetlands for hurricane protection. Ambio 37

Coastal wetlands reduce the damaging effects of hurri-canes on coastal communities. A regression model using 34 major US hurricanes since 1980 with the natural log of damage per unit gross domestic product in the hurricane swath as the dependent variable and the natural logs of wind speed and wetland area in the swath as the independent variables was highly significant and ex-plained 60 % of the variation in relative damages. A loss of 1 ha of wetland in the model corresponded to an average USD 33 000 (median USD 5000) increase in storm damage from specific storms. Using this relationship, and taking into account the annual probability of hits by hurricanes of varying intensities, we mapped the annual value of coastal wetlands by 1km 3 1km pixel and by state. The annual value ranged from USD 250 to USD 51 000 ha1 yr1, with a mean of USD 8240 ha1 yr1 (median USD 3230 ha1 yr1) significantly larger than previous estimates. Coastal wetlands in the US were estimated to currently provide USD 23.2 billion yr1 in storm protection services. Coastal wetlands function as valuable, selfmaintaining ‘‘horizontal levees’ ’ for storm protection, and also provide a host of other ecosystem services that vertical levees do not. Their restoration and preservation is an extremely cost-effective strategy for society