Will Rising Seas Overwhelm Louisiana’s Coastal Restoration Plans?

's coastal restoration plans

Bren Haase (L) of the Louisiana Coastal Protection and Restoration Authority shakes hands with Col. Stephen Murphy of the New Orleans District office of the Army Corps of Engineers.. Photo by Travis Spradling

Three years ago, nonresidents in audiences at my presentations on Louisiana’s plan to save its coast by rebuilding wetlands began exposing a serious problem by asking this question: Given the rapid acceleration of sea-level rise, does it make sense to spend tens of billions of taxpayers’ dollars rebuilding wetlands that might be submerged again in 30 or 40 years?

So, I went to the state for an answer.

It didn’t have one. It still doesn’t.

 Now, what was just a troubling question three years ago, could become a project killer in the years ahead.

That’s because two forces are emerging that will make finding national support for adequate funding — always the plan’s biggest hurdle — impossible unless Louisiana can answer that question.

The first force is the latest research showing sea level rise has been accelerating faster than predicted. Even the best-case scenarios in the 2017 master plan show the state could lose another 1,200 square miles by 2067 even with all the projects built. That “best bad news” was based on the world reducing carbon emissions (the factor driving sea-level rise) by 40% over the next 30 years. Sadly, the world has yet to approach that trend.

Sea level rise projections beyond 2067 — the end of the “project life” of many of the state’s marsh creation projects — still show an average of at least two to 3.3 feet of rise by 2100. And that doesn’t include the steady sinking of Louisiana’s sediment-starved deltaic wetlands.

Bottom line: Maps projecting the likely inundation of coastal areas show some of what we are rebuilding might be under water again by 2067 even in so-called “moderate” emissions scenarios. Even more would be submerged in following decades if emissions are not dramatically reduced starting now.

Read the rest of the article at The Times-Picayune.