Contoversy about Louisiana’s coastal master plan for sea level rise

Bob Marshall in the Advocate via the Lens (Louisiana): Yes, we can. And, by the way: You’re wrong. That’s how Garret Graves, head of the Louisiana Coastal Protection and Restoration Authority, and some coastal scientists have responded to federal researchers who last week predicted the southeast coast faces the highest rate of sea level rise “on the planet” – 4.4 feet by 2100.

At that rate, they said, parts of the state’s coastal Master Plan will be obsolete before they are completed. “The NOAA folks are just misinformed,” said Graves, summing up a point-by-point email rebuttal of the claims made by National Oceanic and Atmospheric Administration staffers in a story by The Lens.

Requests for a response from Graves and others involved with the Master Plan had gone unanswered when the story on the NOAA claims was published. Now they have fired back. “Yes, we expect things to change, and, yes, we can adapt these projects as we move forward,” he said.

Graves said a central feature of the Master Plan allows projects to be adapted to ever-increasing rates of sea level rise and subsidence, even those higher than predicted in the NOAA scenario.

...The NOAA researchers’ comments were based on new studies showing that the southeastern Louisiana coast, long known to have one of the highest rates of subsidence in the world, is sinking much faster and more uniformly than previously thought. That’s because it rests on the Mississippi River’s collapsing sediment-starved deltas.

When combined with recently released data proving the seas are rising at a faster rate than predicted, those two factors — collectively called “relative sea level rise” — showed the Gulf of Mexico rising 4.4 feet in this area by century’s end.

Tim Osborn, an 18-year veteran of NOAA’s Louisiana coastal surveys, contends that the updated data pose serious new problems for the Master Plan. “The problem is it’s a master plan for the restoration and conservation of a landscape that is moving downward at a faster rate than we realized when the plan was constructed — a rate faster than any place else we are seeing in the world for such a large land area,” he said....

From the US Geological Survey: Holly Beach, Louisiana. Photos of same location in 2001, and in 2005 after the devastation of Hurricane Rita.