As sea levels rise in the coming decades, the strongest effects in the US are likely to be felt along the Gulf Coast, and most dramatically in Louisiana, according to a report from global rating agency KBRA.
KBRA said it had been given access to “Sinking Tax Base, Land & Property at Risk from Rising Seas,” a report from nonprofit news organization Climate Central. Using that report, KBRA looked at risks from rising seas in 328 coastal counties in the US, with a focus on forecast lost acreage.
Louisiana, KBRA said, could account for about 56% of the 4.3 million acres expected to be lost to sea-level rise through 2050. The Atlantic Coast is projected to be at lower risk than the Gulf Coast. The Pacific Coast (including Alaska and Hawaii) will be even less vulnerable, shielded by a steeply sloping terrain.
Overall, the report said, the Gulf Coast accounts for 72% of all forecast acres that may be lost to sea-level rise in the US through 2050. Coastal subsidence will be a significant factor in Louisiana, KBRA said, noting that Louisiana also suffers from sediment compaction and extraction of underground water and fluids. Significant areas of coastal Louisiana are sinking, and they are not being replaced by other natural forces such as sediment flow from the Mississippi River, the report said.
While Atlantic Coast risk is relatively low, KBRA said, the acreage loss is likely to accelerate later in the century. According to KBRA, other states facing significant risk from rising sea levels include Florida, North Carolina, and Texas.
