The Gulf is rising

And now for something completely frightening.

The Louisiana coast is rapidly sinking into the sea. There are efforts and plans to move sediment around to save New Orleans and some pipelines and fishing grounds, but much of the Delta is doomed (and the planned fixes are hugely expensive, and Louisiana is a  poor state).

Southeastern Louisiana might best be described as a layer cake made of Jell-O, floating in a swirling Jacuzzi of steadily warming, rising water. Scientists and engineers must prevent the Jell-O from melting — while having no access to the Jacuzzi controls.

The problem is human-made. Over the last 80 years, Louisiana’s coast has been starved of sediment by river levees and eviscerated by canals dredged for oil and gas extraction. Now, southeastern Louisiana is sinking at one of the fastest rates on the planet as the Gulf is rising.

Already, 2,000 square miles have sloughed into the Gulf. Without action, the state could lose another 1,750 squares miles over the next 50 years.

If that happens, in 70 years New Orleans could be left on a razor-thin sliver of land extending into the open Gulf, battered by storms rolling over the watery graves of unprotected communities.

The economic effects will reverberate across the nation as the seas swamp half of the nation’s refineries and pipelines that transport 30 percent of the country’s oil and gas. The country’s largest port, an economic door to 31 states, would be vulnerable to run-of-the-mill tropical storms, causing shutdowns that cost the nation’s economy an estimated $300 million a day.

Not a trivial problem.

Most of us have known at least some of that ever since Katrina, but it’s easy to lose sight of just how drastic the situation is.

And the proposed fixes are no guarantee of anything themselves, because any fix they can do will have consequences elsewhere and it’s a mammoth engineering task to figure all that out. Sending a box to Mars looks easy in comparison.

“My concern is that a lot of people think if we just turn the river loose, it will just fill in all those holes we’ve created in the delta,” said Roberts. “Well, certainly it’s not as simple as punching holes in the levees.”

Every diversion project is a move in an ongoing chess match with nature. Each one faces different sets of variables and constraints, and engineers are struggling to anticipate the consequences of each step they take.

“Everything you do at one point on the river — anything you take out or put in — will have an effect on the rest of the river,” said Alex McCorquodale, a University of New Orleans researcher working on a study to determine how much sediment is in the lower Mississippi.

It’s a matter not so much of finding a fix as of juggling bad consequences in different places, or even the same places.

Considering how much remains unknown, a few scientists ask why Louisiana has staked so much on diversions. They worry the state could waste its last chance for the coast on a technique they believe poses its own habitat threats and exists only on computer models.

Gene Turner, a distinguished LSU coastal researcher, points to studies that show high levels of nutrients from fertilizer upstream can cause wetlands loss by damaging plants in areas with high organic soils. He is concerned that the state doesn’t have a backup plan if its computer models are wrong.

“Every building code requires a fire exit, and right now this plan doesn’t have one,” he said. “Saying, ‘This is going to work’ isn’t a backup plan, not when you’re doing something that has never been done before, except on computers.”

Turner has the minority view in the coastal scientific community. Nonetheless, the state coastal agency has asked the Water Institute of the Gulf to gather a panel of outside coastal experts to look into those questions.

And then, all this depends on climate predictions, and there’s reason to think current predictions could turn out to underestimate the rate of climate change.

So read the whole thing; it’s an education in itself.



  1. brett says

    Sorry to hear that, although it’s kind of cool imagery to imagine New Orleans as this Island Sanctuary City surrounded by the sea and only connected to the US by a thin land bridge.

  2. quixote says

    I was a grad student at Tulane in the late 1980s and took many field trips out to the Gulf swamps. Some of them were to help a researcher studying sedimentation rates. Biologists knew then that what is happening now was going to happen. Even then, it would have been expensive to do anything about it, but about one hundredth or one thousandth what it costs now. And one millionth of what it will cost in a few years.

    There are two main causes of the problem. Levees along the Mississippi push all the sediment out at one spot near Venice ( and make Gulf dead zones) instead of winding up at different spots all over southern Louisiana as the river makes itself new channels every year.

    The second issue is the oil and gas industry which cut channels all through the wetlands to move equipment and build pipes. Salt water intrudes along those channels and kills the vegetation. The dead vegetation doesn’t hold onto the “jello” soil anymore, and the whole thing washes out to sea on the tides. There are early satellite photos of the area, which look like green wetland, and recent ones where the whole thing looks like lacy spider webbing on water.

    And, yes, diversion of the river in its current state of pollution and fertilizer load could well create more problems than it solves. Telling the oil and gas industry to restore all the wetlands they ruined is probably also “too expensive.”

  3. quixote says

    By the way, the only part of New Orleans above sea level is the very old part of town and the sliver along the river. Not a lot of sanctuary, especially when sea level rises. There is no land bridge to the mainland. And the causeways would have to be raised.

  4. Stevarious, Public Health Problem says

    “Louisiana is a poor state”
    “Over the last 80 years, Louisiana’s coast has been starved of sediment by river levees and eviscerated by canals dredged for oil and gas extraction.”
    “half of the nation’s refineries and pipelines that transport 30 percent of the country’s oil and gas”

    Anyone see something wrong with the combination of those statements?

    Clearly allowing corporations to strip the state of its wealth, pay as few taxes as possible, and not be held accountable for the damage was the best idea. Ayn Rand would be proud of this outcome.

  5. K.R. Syncanna says

    Their attempts to save the coast will be short-lived “solutions” that could possibly make the problem worse if they do not continuously pour money into the project. Sedimentology is a really damning subject in regards to human behavior.


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