The Economist
WHEN Roosevelt Falgout was a boy, the brackish water that now laps within a few feet of his three-room cabin at Isle de Jean Charles was miles off. “There were only trees all around, far as you could see,” recalls the 81-year-old former oyster fisherman, at home on the Isle, a sliver of land in the vast marsh that covers much of southern Louisiana. He and his village’s other men and boys, who are members of the French-speaking Biloxi-Chitimacha-Choctaw tribe, used to hunt and trap muskrat and mink in those oak and hackberry forests.
But salty water, seeping northward from the Gulf of Mexico, killed the trees off long ago; just a few blackened stumps remain, protruding from the open water that now surrounds the Isle. With even a modest storm liable to flood the island and the narrow causeway that connects it to higher ground, the village has become almost uninhabitable. Mr Falgout’s 81-year-old wife, Rita, says she lies awake at night worrying that her husband, who has cancer among other ailments, will have a medical emergency during a flood. “It’s become too frightening here,” she says of her ancestral home, sitting amid a clutter of family photographs, Native American beadwork and Catholic saints. The Isle’s 60 residents are due to be resettled further inland, in a $48m programme approved by the state government last year, and Mrs Falgout says she cannot wait to go.
The briny intrusion that has put paid to the Choctaw village is devastating southern Louisiana. Between 1932 and 2010 the state lost more than 1,800 square miles (470,000 hectares) of land to the sea, representing about 80% of America’s coastal erosion over the period. Recent losses have been especially severe because of an increase in big storms raging in from the Gulf of Mexico—such as Hurricane Katrina, in 2005, which led to the inundation of New Orleans and 1,836 deaths. Between 2004 and 2008 alone, Louisiana shrank by more than 300 square miles.
This is one of America’s biggest environmental crises. Louisiana contains some of the world’s most extensive wetlands, home to a fifth of North America’s waterfowl. It is an economic and human disaster, too. The threatened coastal area is home to 2m people and a hub of the oil-and-gas industry. It is also the main export point for liquefied natural gas (LNG), the form in which American shale gas is shipped abroad. Southern Louisiana contains five of America’s 12 busiest ports and billions of dollars of oil-and-gas infrastructure, including 16 petroleum refineries and thousands of miles of pipeline. In Cameron Parish, one of the state’s nine coastal districts, all of which are being eroded by the sea, $30bn-worth of new or repurposed LNG infrastructure is under construction. According to a new report by RAND Corporation, a think-tank, infrastructure in the state worth up to $136bn could be threatened by land loss and increased storm damage, a related threat.
Such numbers focus attention. The effort to shore up Louisiana against the hungry sea, which is run by a state body, the Coastal Protection and Restoration Authority of Louisiana (CPRA), but combines many federal, state and local efforts, costs around a billion dollars a year. In one of America’s most Republican states, it is also bipartisan, well-managed and impeccably science-based.
Over the past decade the CPRA has restored 36,000 acres of marshland and dredged up 60 miles of artificial islands, to provide a buffer for the coastline. The agency’s latest five-year action plan, approved in April, includes 124 planned or active projects, designed to restore or protect an additional 800 square miles of land over the next half-century, at a cost of $50bn. American taxpayers will cover most of that; BP, an oil firm, will provide $15bn, as compensation for the Deepwater Horizon oil spill in 2010. The plan was approved without a whisper of dissent from the legislature, even though parts of it read like a publication of the Intergovernmental Panel on Climate Change, on whose sea-level-rise projections it is indeed based. With its “long-term view, consideration of climate change, and integration of natural systems and community resilience”, the CPRA claims its report “leads the nation in ecosystem-restoration thinking.”
Many scientists would agree. “No other state has a science-based, environmental restoration and protection project of this rigour,” says Justin Ehrenwerth, a former member of Barack Obama’s administration, who now runs the Water Institute of the Gulf, a research outfit in Baton Rouge dedicated to mitigating coastal erosion. Many Republicans also agree. “I can’t choose the best investment without using the best available science,” says Garret Graves, a former head of the CPRA, who now represents Louisiana’s sixth district in the House of Representatives. “I’ve heard people in this building say sea-level rise isn’t happening,” he says, seated in his office on Capitol Hill. “I can tell you it is, because I’ve measured it.” Such bipartisan consensus, rare in America on any issue, is especially striking on one fundamentally linked to global warming, which many Republicans profess not to believe in. This makes Louisiana’s coastal trials, even beyond their environmental and economic significance, an important indicator of how American policymakers will respond to the worsening effects of climate change.
Flowing out, flowing in
To understand what is causing the inundation, consider how the land was made. Most of southern Louisiana, as well as parts of seven other states, including Arkansas, Mississippi and Missouri, form the Mississippi deltaic plain, a fertile region created over the past 8,000 years by the Mississippi bursting its banks, slowing, and then depositing sediments over the surrounding area. The vastness of the plain—Louisiana’s coastline alone is 400 miles long—reflects the Mississippi’s huge reach and sediment load; the river, which drains 41% of the contiguous United States, is estimated to transport around 400m tonnes of sediment a year. It also reflects how dynamic the Mississippi is. As it meandered through its delta, the river, for most of those millennia, constantly changed its course through siltation and erosion. Every 1,000 years or so, it abandoned its main channel for one of its distributaries. A time series of the Mississippi’s course looks like a sinuous Celtic knot, with a swathe of interwoven curves, flowing to the sea.
Widespread flooding is not compatible with modern living, however. The first levees of the Mississippi were thrown up around New Orleans in the 18th century. After flooding in 1927 displaced over 600,000 people, Congress ordered almost every untamed reach of the river to be straitjacketed by earthworks. Over 1,500 miles of levees were constructed, confining the Mississippi from its source in Minnesota almost to its mouth. This has had some beneficial effects. It has made the river’s course more predictable for shipping and accelerated its flow, mitigating the effects of siltation. But it has starved the delta region of the sediment deposits to which it owes its existence.
This alone would be sufficient to cause massive erosion. But two other man-made factors have meanwhile boosted the corrosive power of the sea—the yin to the Mississippi’s yang.
Since natural gas was first observed bubbling from a rice paddy in coastal Louisiana in 1901, thousands of oil wells have been sunk into the wetlands. To reach them, almost as many canals have been dredged from the Gulf by energy companies. These channels have injected seams of saline water deep into the marshes, killing plants which tolerate only fresh or brackish water, such as the marsh and woodland species that once surrounded Isle de Jean Charles. This has in turn reduced the amount of organic matter the marshes produce, which acts as a counterweight to another reductive process, the constant settling and compacting of the organic platform that raises the marshland above the water table.
At Pointe-Aux-Chenes, another Native American village a couple of miles inland from the Isle, this transformation is vividly apparent. The small bayou, or waterway, running beside the village has turned salty and almost laps at the road alongside it. The live oaks that gave the village its name (“chêne” means “oak” in French) are giving way to marsh reeds and other estuarine species. As your correspondent surveyed the waterway, a pair of bottlenose dolphins—apex predators in estuarine conditions—arched gracefully from the water.
Starved of silt, and with less new organic matter to counteract its settling, coastal Louisiana is sinking back into its former watery state. Meanwhile, because of melting polar ice caps and thermal expansion, the sea level is rising. In the past decade the observed relative sea-level rise in coastal Louisiana—a figure that combines the effects of rising seas and subsiding land—was over a centimetre a year, or around four times the global average. The delta’s system of land creation has thus been thrown into reverse. In 1930, despite much engineering of the Mississippi’s channel, Louisiana was expanding by almost a square mile a year. Since then, an area the size of Delaware has been lost to the Gulf.
Much of the CPRA’s work involves dredging up sediment where it is abundant, including under the sea, and piping it to areas of threatened marshland. Behind an artificial beach in Cameron Parish, Brett Dupuis, a project manager for Weeks Marine, a dredging company, is working on a $31m project to restore 740 acres (300 hectares) of submerged marsh, which was inundated by the sea during Hurricane Rita in 2005. For three months his dredging platform, two miles offshore, has been sucking up dirt from the sea bed and piping it ashore. The result, where open water used to be, is a bed of grey ooze up to ten feet deep, with a slurpy fountain of gunk where the dredging pipe empties into it. “Good thick stuff,” nods Mr. Dupuis approvingly, as laughing gulls and brown pelicans wheel and chatter overhead.
Welcoming back the water
It is heartening to observe a habitat formed over centuries being recreated in a few weeks. It also illustrates how Canute-like this approach is. Thousands of square miles of Louisiana are in the process of disappearing; they cannot be replaced by diesel-powered engines an acre at a time. Or, as Mel Landry of the National Oceanic and Atmospheric Administration puts it, while inspecting Mr Dupuis’s progress: “We’ve got more work to do than we could ever pay for.”
Even assuming the CPRA gets the $50bn it is angling for, it predicts another 1,450 square miles of Louisiana will be lost over the next 50 years. That also assumes the agency is permitted to carry out a more ambitious and controversial sort of marsh-regeneration project, by carving floodgates into the Mississippi’s levees and, at times when the river’s sediment load is high, opening them to inundate the silt-starved plain. The most advanced such scheme, known as the Mid-Barataria Sediment Diversion, would create a channel from the Mississippi, south of New Orleans, capable of funnelling 75,000 cubic feet (2.1m litres) of silty water per second into badly eroded Plaquemines Parish. In full flow, the channel would carry water equivalent to the seventh-largest river in America. The scheme would cost $1bn and is currently being appraised by the US Army Corps of Engineers, which oversees the management of the Mississippi’s levees.
To preserve southern Louisiana in something close to its current shape, many such diversions might be required. Experts enthusiastically say they could reconnect the river to the delta; others doubt they would work as intended because, as a result of dams and dredging upstream, about half the Mississippi’s sediment no longer reaches its lower course. The boosters are probably right: a big distributary of the Mississippi, the Atchafalaya, which siphons off about a third of the river’s water and more of its sediment load in central Louisiana, has had its basin leveed, but not its banks, and it is making land. Yet resistance to the mooted diversions is fierce.
Such schemes were first discussed in the 1990s, when the scale of the land loss began to be recognised by policymakers. They have since been blocked by a couple of well-organised groups, led by the state’s powerful oyster farmers, who have crept further inland with the estuarine conditions in which oysters thrive, and do not want to see their stocks wiped out by a gush of muddy water.
The Corps of Engineers, a slow-moving bureaucracy that distrusts green infrastructure and is reluctant to build floodgates in its levees, presents a different challenge. It says it will take five years merely to review the feasibility of the Mid-Barataria scheme. At the current rate of loss—about a football-field of land every hour—Louisiana will change a lot while the agency deliberates. “The Corps is incapable of responding with the necessary urgency to the coastal erosion crisis in Louisiana,” says Congressman Graves. “The main reason for the erosion is levee-building. It amazes me that the Corps has no sense of guilt about their responsibility. They have an obligation to fix what they broke.”
The damaging effect of the levees was predicted. Weighing the benefits of engineering the Mississippi in 1897, a former president of the American Society of Civil Engineers, E.L. Corthell, noted the need to take into account “withholding by the levees…of the annual contributions of sedimentary matters” and, because of this, “subsidence of the Gulf delta lands below the level of the sea and their gradual abandonment.” But while he warned that “the present generation should not be selfish,” Mr Corthell assumed the economic benefits of protecting the flood zone would “be so remarkable that people of the whole United States can well afford, when the time comes, to build a protective levee against the Gulf waters.”
That illustrates two related weaknesses in much environmental policymaking: an assumption that future politicians will take a longer-term view than current ones, and an excessive willingness to discount the future costs of solving environmental problems caused today. President Donald Trump, though eager to splurge $20bn on an unnecessary border wall, appears not to have given thought to the seawall Mr Corthell envisaged. In any event, it is doubtful such a scheme would be affordable or otherwise practical, considering the effects of rising sea levels and fiercer storms, both consequences of global warming, which the Republican president either does not believe in or care about.
In a dither
Some of the hoped-for diversions, at least, will probably be built. The political consensus in Louisiana for such action is apparent at every level of government. “We’re all pulling together on this,” says Ryan Bourriaque, the administrator of Cameron Parish. “It’s a great example of how industry, conservationists and different government agencies can all marry.” Mr Graves, who recently became chairman of a House subcommittee that oversees the Corps of Engineers, will also chivvy it relentlessly. Yet anyone looking to Louisiana for hope that America will develop a more rational climate policy is liable to be frustrated. The state’s impressive coastal policy illustrates America’s ability to adapt to a natural disaster that is already upon it. It does not seem to have nudged the state, or the Republican Party, any closer to policies that might slow the warming that is contributing to that disaster.
Louisiana’s former governor, Bobby Jindal, was a strong supporter of the CPRA. While preparing to run for the Republican presidential ticket in 2016, he nonetheless described climate change as a “Trojan Horse” for a left-wing power grab: “It’s an excuse for some who never liked free-market economies and never liked rapid economic growth.” Mr Graves, remarkably, given how averse he seems to talking nonsense on scientific matters, says he shares that view. He also, despite his reliance on the IPCC’s sea-rise projections, says he does not accept the scientific body’s consensus that most of the observed recent warming is caused by human activities.
The way things were
To plan hugely expensive government action on the basis of the latest climate projections, but at the same time to claim the science underpinning them is too weak to justify curbing greenhouse-gas emissions, as most climate scientists recommend, is at best inconsistent. Perhaps it truly reflects Mr Graves’s thinking. It also seems possible that he wants to keep onside the energy companies which provide around 40,000 jobs in Louisiana and donate generously to his political campaigns. Those firms are responsible, directly and indirectly—through their canal-dredging and because of the greenhouse-gas emissions they facilitate—for a lot of Louisiana’s coastal erosion. Yet Mr Graves, moral scourge of the bureaucratic Corps, is also opposed to several ongoing legal campaigns to make the companies pay compensation for the damage they have caused.
It is hard to make sense of this, except perhaps by recourse to Mr Corthell. The present generation should not be selfish. But it always is.