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That Louisiana is sinking into the Gulf of Mexico is not news. Rising seas and coastline erosion have been working together for decades, but this sinking may well be happening faster than previously thought—threatening billions and billions of Louisiana oil infrastructure.This is the central idea of a new study from Tulane University that set out to map the Louisiana coastline using new methods of measuring subsidence—the technical term for sinking land. The outcome of the measurements is an average 9 mm of wetlands lost to the sea every year. This compares to previous estimates of an annual subsidence rate between 1 to 6 mm.
The authors warn that there are differences in the rate of sinking at different locations along the coast, but overall, we are already seeing what other authors in earlier studies have estimated as the worst-case scenario for the future.
There is grim irony in the fact that according to the Tulane University researchers, the main reason for the accelerated sinking is the loss of sediment carried by the Mississippi River to the coast because of the numerous levees aimed at protecting cities and industrial infrastructure from flooding. Now, Gulf waters are advancing, and it is making flood threats more serious as natural defenses such as marshes are being swallowed by the sea. So is oil infrastructure.
A 2016 report from Bloomberg warned that the oil industry is having to deal with US$ 100 billion worth of infrastructure on the Louisiana coast that is being threatened by the combined forces of rising sea levels and subsidence. The report cited a study from America’s Wetlands Foundation and Entergy Corp, which found that annual losses for Big Oil already amounted to US$ 14 billion. This could balloon to a total US$ 350 billion by 2030.
The Washington Post notes in its report of the new study that the Louisiana Legislature recently approved funding of US$ 50 billion for the restoration of the coastline, but this is nowhere near enough, it would seem—all the more so given that the US$ 50 billion will be spent over a period of 50 years, and four of the five most expensive projects in this master plan are focused on marsh creation—the once natural defenses of the coast against the corrosive effect of seawater.
The situation certainly looks like it requires urgent measures and this makes accurate measurement of the sinking rates all the more important. One of the study authors, Torbjörn Törnqvist, told the Washington Post that there is more work to be done in this direction—the map that the team outlined based on their measurement showed the big picture, he said, rather than specific subsidence rates at different locations.
Knowing the specific rates at which the land is sinking in specific locations will help more focused efforts for restoring those parts of the coastline that need the most urgent restoration. Or, as associate professor Alex Kolker from the Louisiana Universities Consortium put it to the WT, “the amount that the area is sinking directly impacts the amount of mud that you need to fill the area and to restore a marsh.”
The oil industry, which has had a part to play in the damage, is one obvious source of funding for the restoration effort, but it seems Big Oil is a bit reluctant to take part. ConocoPhillips, Chevron, and Citgo last year partnered with America’s Wetlands Foundation on a pilot project in erosion mitigation, but there have been few other signs that energy companies are willing to partake in the state’s master plan.
Of course, there are the US$ 8 billion that BP had to pay to Louisiana after the Deepwater Horizon disaster, but that’s small potatoes in the wider, long-term coastal restoration plan. Lawsuits against oil companies by local authorities are one way of getting money out of them and using it to restore the coastline, but the industry believes this is not the right way – oil and gas companies are already paying indirectly for coastline restoration with the royalties they pour into the state coffers for their activities in the Gulf, they argue.
The oil industry is certainly not the only culprit behind the quickly sinking Louisiana coast. It may not even be the biggest culprit—remember those levees. Yet it is in its own interest to protect the infrastructure it operates on this sinking coast.