Will the North Sea be transformed into a lake to combat rising water levels?

Will the North Sea be turned into a lake to combat rising water levels?


A Dutch government scientist has proposed building two titanic dams between Scotland, Norway, France and England to completely close off the North Sea. These giant constructions would be able to protect around 25 million Europeans from the consequences of rising sea levels due to global warming.

Sjoerd Groeskamp, an oceanographer at the Royal Netherlands Institute for Marine Research, is working on a singularly ambitious idea. He claims, with proof and figures to back it up, that a 475 km dam between northern Scotland and western Norway and a 160 km dam between western France and southwest England was "a possible solution" to stem the inevitable flooding that will occur as a result of rising oceans.

In an article to be published this month in the American Journal of Meteorology, which The Guardian has reported on the first testsSjoerd Groeskamp and Joakim Kjellsson of the Geomar Centre for Ocean Research in Kiel, Germany, say the idea is affordable and technically feasible.

On the basis of existing projects, in particular the large-scale dams built in South Korea, scientists estimate the cost of building a so-called "North Sea enclosure" dam at between €250 and €500 billion. They argue that, spread over 20 years, the annual cost for the 14 countries that would be protected by this dam would amount to just over 0.1 % of each country's GDP.

If these calculations are correct, the project therefore appears to be economically viable in view of the material and human damage caused by the gradual rise in sea level and increasingly devastating flooding inland.

Technically viable

According to Groeskamp, this solution also appears to be technically viable. The depth of the North Sea between France and England rarely exceeds 100 metres, while between Scotland and Norway it averages 127 metres, with a peak at just over 320 metres off the coast of Norway. "We are currently able to build fixed platforms at depths in excess of 500 metres, so such a dam seems feasible," he said.

Why not enjoy unlimited reading of UP'? Subscribe from €1.90 per week.


  • The South Dam would cross the English Channel between Cornwall and Plouescat in Brittany. It would be 161 km long and would be built on bottoms that do not exceed 100 meters. This dam would also allow road and perhaps rail transport between the continent and England.
  • The North Dam is more complex, consisting of multiple sections. The eastern section of the North Sea Dam would be the biggest technical challenge. It would be 331 km long in open water and would sit on a seabed over 300 m deep in the Norwegian trench. The dam would start from the eastern shore of Shetland, most likely from the island of Noss, and follow an eastern direction towards the island of Sotra in Hordaland on the west coast of Norway.

Building these two dams would have unimaginable consequences. The project would turn a large part of the North Sea into a vast, tideless freshwater lake, radically altering its ecosystem. On a smaller scale, this is what already happened in 1933 when the Dutch built the 32 km long Afsluitdijk dam. By closing off a large entrance to the North Sea, now the freshwater lake IJsselmeer, the construction made possible the largest land reclamation project in history. The Zuiderzee - of which the Afsluitdijk was a key element - and the Deltaworks, a vast series of dams, locks and storm barriers protecting the southwest of the Netherlands from the sea, are widely regarded as marvels of hydraulic engineering.

The idea is not that far-fetched and the international experts who have looked at this project have agreed that it appears to be technically viable. « I guess it depends on the time scale we think about."said Hannah Cloke, Professor of Hydrology at the University of Reading. « Sf you look back in the past, hundreds and hundreds of years, then we've made significant adaptations to our landscape, and the Netherlands is an example of that. We can, as humans, do amazing things ». The scientist adds: " I think it's really important that we keep thinking about these ideas, because the future looks very scary. "

The two authors of the project claim that a 10-metre sea level rise is expected in the long term, under the worst-case scenarios. The dam is therefore primarily a call to act now to combat climate change. If we do nothing, this extreme dam may be the only solution. The situation is indeed alarming: according to projections by climate experts, based on the current situation, we should reach 84 cm of sea level rise by the end of the century and more than 5 meters in 2300. Many European countries would then be wiped off geographical maps.

Nous avons un message pour vous…

En octobre dernier nous avons pris l’engagement que UP’ Magazine accordera au dérèglement climatique, à l’extinction des espèces sauvages, à la pollution, à la qualité de notre alimentation et à la transition écologique l’attention et l’importance urgentes que ces défis exigent. Cet engagement s’est traduit par le partenariat de UP’ Magazine avec Covering Climate Now, une collaboration mondiale de 250 médias sélectionnés pour renforcer la couverture journalistique des enjeux climatiques.

Nous promettons de vous tenir informés des mesures que nous prenons pour nous responsabiliser à ce moment décisif de notre vie. La désinformation sur le climat étant monnaie courante, et jamais plus dangereuse qu’aujourd’hui, il est essentiel que UP’ Magazine publie des rapports précis et relaye des informations faisant autorité – et nous ne resterons pas silencieux.

Notre indépendance éditoriale signifie que nous sommes libres d’enquêter et de contester l’inaction de ceux qui sont au pouvoir. Nous informerons nos lecteurs des menaces qui pèsent sur l’environnement en nous fondant sur des faits scientifiques et non sur des intérêts commerciaux ou politiques. Et nous avons apporté plusieurs modifications importantes à notre expression éditoriale pour que le langage que nous utilisons reflète fidèlement, mais sans catastrophisme, l’urgence environnementale.

UP’ Magazine estime que les problèmes auxquels nous sommes confrontés dans le cadre de la crise climatique sont systémiques et qu’un changement sociétal fondamental est nécessaire. Nous continuerons à rendre compte des efforts des individus et des communautés du monde entier qui prennent courageusement position pour les générations futures et la préservation de la vie humaine sur terre. Nous voulons que leurs histoires inspirent l’espoir.

Nous espérons que vous envisagerez de nous soutenir aujourd’hui. Nous avons besoin de votre soutien pour continuer à offrir un journalisme de qualité, ouvert et indépendant. Chaque abonnement des lecteurs, quelle que soit sa taille, est précieux. Soutenez UP’ Magazine à partir d’1.90 € par semaine seulement – et cela ne prend qu’une minute. Merci de votre soutien.

Je m’abonne →

The oldest
Most recent Most Votes
Inline Feedbacks
View all comments
Will Australia's mega-fires have an impact on the global climate?
Previous article

Will Australia's mega-fires have an impact on the global climate?

Next article

How are we going to live in the "urban furnaces"?

Latest articles from Climate



Already registered? I'm connecting

Inscrivez-vous et lisez three articles for free. Recevez aussi notre newsletter pour être informé des dernières infos publiées.

→ Register for free to continue reading.



You have received 3 free articles to discover UP'.

Enjoy unlimited access to our content!

From $1.99 per week only.