Rising sea levels provoke exodus from northern French coastline

Rising water levels in Normandy, France are causing an exodus of residents as properties are threatened by the receding coastline, prompting authorities to warn of the need for relocations.

The Manche department has already pledged €8million to help fund the first relocations away from cliff edges. Threatened coastlines include the cliffs at Cotentin, the white cliffs of Seine-Maritime, the salt flats in Manche, and the beaches in Calvados.

Research from 23 professors and researchers at the Universities of Caen, Rouen, and Le Havre estimate that up to 50% of the three departments’ coastlines are directly threatened by the rising water.

Jean Morin, president of the Manche departmental council, told Le Figaro: “The only unknown is when [exactly] it will happen.”

Read more: Map: The 101 French communes affected by coastal erosion

The situation has been caused by a perfect storm of factors:

• Stronger tides
• Regular erosion of cliff areas
• More frequent storms
• Flooding
• Rising sea levels of 5mm per year
• Water tables infiltrated by salty water

In Manche alone, researchers estimate that 36,000 hectares of land are threatened by encroaching seawater. Areas in ‘low zones’, meaning those five to six metres below sea level, are particularly at risk.

Action required

Stéphane Costa, co-chair of the Normandy Intergovernmental Panel on Climate Change (IPCC) and professor at the University of Caen-Normandy, believes that it is no longer time for observations, but for action.

He told Le Figaro: "The impacts of climate change are already underway in Normandy. I know that this is easy for a researcher to say, perhaps less so for an elected official, but we must prepare ourselves now.

“If we let it happen, nature will require emergency management, which is generally a bad idea and often more expensive. The longer we wait, the more it will cost.

“It’s not a question of creating a no man's land along the coast, but rather of getting goods and people out of dangerous areas. To do this, we need to take the time to gain public acceptance, and organise territorial support.”

The €8million pledge in Manche will go towards raising public awareness, to funding ‘defence’ operations, such as repairing existing fissures, and to help people relocate where necessary. One study has already said that the cost is estimated at an average of €100,000 per household.

However, Valérie Nouvel, vice-president in charge of climate change transition and adaptation, said: “The problem is that most of our fellow citizens are not yet ready to hear it, so they don't hear it. The question now is not how to talk about it, but to show that the sea is definitely rising and we must start taking action.”

Department president Jean Morin added: "The awareness of our fellow citizens is, unfortunately, often inversely proportional to the number of kilometres that separate them from the sea!”

He added that the public still has not grasped the issue, given that property prices have been rising sharply along the Normandy coast since the Covid crisis. One property expert said: "The tipping point will be the day when insurers refuse to continue to insure. Then the market will suddenly collapse and there will be no time for tears.”

The sea also appears to be rising much faster than initially thought. One area in Val de Saire had thought that the sea would rise to dune level by 2040. It actually happened in 2018.

In Saint-Jean-de-Thomas, near Mont-Saint-Michel, the high-water mark of the tide has encroached by more than 370m since the 1940s in the dune area.

‘The sea is stronger than man’

Ms Nouvel said that rather than talking about ‘relocalisation’, she prefers the term ‘spatial reworking’, to avoid the negative associations of moving. She said: “It sounds less negative and enables us to rethink networks like roads, electricity, and drinking water.”

Local coastal engineer Clément Nalin said: “The sea is, and always will be, stronger than man. Today, when you build a structure to combat erosion, you know that the sea will always attack it to get through, which will force you to extend it ad infinitum and thus continue the artificialisation of the land.“

This was particularly evident in the case of two coastal campsites in recent years. First, textiles and sandbags were placed along the dunes. Yet, these tend to explode and move during major storms. So engineers added longer sand ‘tubes’, and then shored them up with large rocks.

However, the sea continued to win. The campsites are now scheduled for relocation.

Hervé Morin, president of the Normandy region said: “I think this is something our compatriots are struggling to grasp; humans cannot fight against the sea.”

The region has offered €15million in funding to help with relocations of businesses and homes. Mr Morin has also called for “support from non-coastal areas” and places to which businesses and households will be relocated.

The regional council is set to present around 100 recommendations based on the conclusions of the Normandy study into the phenomenon.

Article edited November 9 to clarify rising sea level at Saint-Jean-de-Thomas

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