Southern Louisiana sinks into the sea | climate change

Thousands of square kilometers of land in the Mississippi Delta on the south coast of the USA have already been flooded. The causes are climate change and rising sea levels.

Climate change, rising sea levels, gas industry

The unique marshland of the Mississippi Delta – habitat of many rare animal and plant species – is in danger of being destroyed. The oil and gas industry and severe hurricanes put additional strain on people and nature. And also the oil spill from Deepwater Horizon still has an effect.

Louisiana: Construction of levees and canals makes the situation worse

The huge swamp area on the south coast of the USA is a unique ecosystem with rare species of fish, amphibians and birds. But both the Mississippi Delta marshland and New Orleans are doomed. Entire regions are submerged in water every day. In the last 100 years, 5,000 square kilometers have been washed over by the sea. The reasons for this are diverse:

• The consequences of climate change are causing rising sea levels and increasingly violent cyclones
• The construction of dikes encourages the land to subside
• The construction of canals for shipping and the impact of the oil and gas industry are making the situation worse

Climate change is clearly noticeable in the Gulf of Mexico. “Sea-level rise is eating away at our wetlands,” says Cynthia Sarthou. The director of the environmental organization “Healthy Gulf” has been working to save the endangered coastal landscape for almost 30 years. The south of Louisiana is particularly affected, says the 65-year-old, because the increasingly frequent hurricanes with their storm surges accelerate erosion.

Paradox: protective dikes often responsible for land loss

In fact, many people have left the Louisiana shores. Many were forced to leave their homes after the devastation of Hurricane Katrina in 2005 and have never returned. It sounds paradoxical, explains Cynthia Sarthou, but protective dikes are often responsible for land loss because they prevent sediment replenishment. In the 1940s, dikes were built to protect the villages along the river. The problem:

Oil and gas industry is the most important industry in Louisiana

The salt water kills trees and bushes. Roots that otherwise hold the land together are missing. As a result, the sensitive marshland is exposed to erosion and is disappearing. At the same time, the oil and gas industry is the most important industry in Louisiana. The state has the highest density of oil refineries – with a significant impact on people and nature.

Shrimp and oyster fishermen struggle to survive

The so-called shrimp, i.e. shrimp fishing, has a long tradition in southern Louisiana. But since the oil spill Deepwater Horizon in the Gulf of Mexico in 2010, the fisheries are in crisis.

Fisherman Tim, whose light blue boat is called “Brothers”, says that his brother has given up the job. Too difficult and not lucrative enough. The shrimp industry in Southeast Louisiana is in crisis. Environmental pollution and climate change are largely responsible for this. Shrimp are losing their habitat and dying – especially in the so-called dead zone in the Gulf of Mexico. This „dead zone“ lies just off the mouth of the Mississippi and is a huge oxygen-poor and therefore dead area. Caused by fertilizer and toxic chemicals that the river has washed into the sea here.

Environmentalists and scientists are working on solutions

Environmentalists and scientists have been working on solutions for decades, not only to ensure the safety of people on the coasts of Louisiana, but also to preserve the species-rich flora and fauna in the swamps.

One of them is architect and river expert Inaki Alday. He researches and teaches at Tulane University in New Orleans. This Sunday afternoon, he’s sitting on the porch of his home in New Orleans’ Garden District. The problem, says the Spaniard thoughtfully, is that people are trying to control the water masses with dikes and pumps. But that won’t work in the long run, says Alday. And if so, then only for a part of the population.

Dikes are both a hope and a problem, explains the scientist. On the one hand, dykes protect people from flooding, on the other hand they cause damage over the long term. Because they not only keep the water out, but also the sediment replenishment from the river. This cannot create a new country. The natural balance is also disturbed by the constant pumping out, explains Inaki Alday. Swamps and marshes dry up.

One solution is more room for the river to give and the restore natural flood cycles. For example, building roads in such a way that the water seeps away when they are overflowed. houses on supports to to buildso that the flood water simply flows through under them, the architect suggests.

Environmentalist Cynthia Sarthou agrees. the river landscape must in addition to that be renatured, she demands. With the help of artificial tributariesdie nutrient-rich sediments transport to gradually come back to fill up land and restoring habitat to birds, fish and amphibians.

Hope for consistent climate policy of the Biden government

As far as the future is concerned, the conservationist is cautiously optimistic. There will be no complete rescue of the delta. Future changes, she says, have to be designed in such a way that they are bearable for nature and people. She is counting on the new US administration.

The people of the Mississippi Delta are being forced to adapt to changes in their habitat. Many hope that the settlements in the delta will survive at least for the next 50 to 100 years. Nobody here wants to imagine what happens after that.

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