A Dutch scientist has come up with the insane plan to dam the entire North Sea. This would turn it into a giant reservoir — or maybe even drain it. And this would be the largest megaproject ever built by humanity: hundreds of kilometers of seawall, billions of tons of materials, and a total cost of 600 billion dollars.
But in the words of that scientist: Is he right about that? Do we need this thing? And if so, why?
! I’m Regis, and today we’ll find out. The name of this humongous megaproject is the Northern European Enclosure Dam It’s actually the brainchild of a couple of scientists — Sjoerd Groeskamp and Joakim Kjellsson — but Groeskamp is the project’s figurehead.
Over the last few years, he’s been popping up on news channels around the world: This is a relatively recent idea actually. In 2020, Groeskamp and Kjellson published a paper which outlined their plan in depth. Two giant seawalls: the Northern European Enclosure Dam North, and the Northern European Enclosure Dam South.
That’s a bit of a mouthful… we’ll call them NEED-north and NEED-south instead. NEED-south would run from the coast of England down to the coast of France. That’s 161 kilometers — significantly longer than any other seawall in the world.
The two largest seawalls that already exist are the Saemangeum Seawall in Korea — that’s 33 kilometers — and the Afsluitdijk in the Netherlands — that’s 32 kilometers. If you added the two of them together, they’d still be less than half the length of NEED-south. An existing project that comes closer in size is the Hong Kong–Zhuhai–Macau Bridge.
That isn’t a seawall — it’s the world’s longest sea-bridge. But it’s still only 55 kilometers. If you added it to the Saemangeum and the Afsluitdijk, the total length of these three giant projects would still fall short of NEED-south.
Here’s another way to think about it. If you decided to take a ferry from England to France, the journey would take you five hours. That’s how long NEED-south would be.
If you rode a ferry down the length of the wall, it would take five hours to reach the end. And believe it or not, NEED-south is actually the smaller of the two NEED seawalls. NEED-north would be three times longer, at a total length of 476 kilometers.
It would start in the north of Scotland, bounce through the Orkneys, up to Shetland, then take a leap to Bergen on the western coast of Norway. On top of all that, there’d be a handful of other dams, plugging these gaps through the fjords. In total, we’re looking at more than 600 kilometers of construction work here, stretching from France, via Britain, up to Norway.
This is all sounding pretty ambitious, right? But it isn’t as crazy as it sounds. Later, we’ll take a proper look at the engineering requirements for this project.
But first… let us take a look at what these seawalls would actually do. They’d totally separate the North Sea and the Baltic from the rest of the world’s main oceans. The two bodies of water would become the world’s largest reservoir, or mega-enclosure, as Sjoerd Groeskamp called it in his paper.
But hold on, hold on. We know what you’re thinking. Why the heck would we even need this thing?
It’s actually pretty simple. Let’s talk about: Rising Sea Levels Since 1880, sea levels have risen by just over 20 centimeters. The exact cause of this rise is complex, but it comes down to a couple of principles.
First, as a result of climate change, the polar ice caps have been melting. Second, seawater expands when it’s warm. As the planet heats up, and the oceans warm, the water literally grows.
This process is just getting started. By 2100 — in the worst case scenario — global sea levels could have risen by two meters. Just imagine the impact: that water would flood into coastal communities all around the world.
Hundreds of millions of people would be affected. Groeskamp’s paper puts it bluntly. Rising sea levels are an “unprecedented threat to society as we know it.
” And he isn’t the only one. Recently the UN chief called rising seas a ‘worldwide catastrophe’ that especially imperils Pacific paradises. This overview from our sponsor Ground News is based on 120 articles covering this topic.
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news/MegaBuilds or clicking my link below, you can get a massive 40% off their Vantage subscription, the same plan we use. Give it a try and thanks to Ground News for sponsoring our video. And now back to the insane plan of damming the North Sea.
By isolating the North Sea and the Baltic Sea from the rest of the world’s oceans, these bodies of water would be totally protected from the threat of rising sea levels. The level of the Atlantic could go up and up, but the excess water would be held back by NEED-north and NEED-south. This would make a massive difference to fifteen countries on the frontline: Belgium, Denmark, England, Estonia, Finland, France, Germany, Latvia, Lithuania, Poland, the Netherlands, Norway, Russia, Scotland, and Sweden.
Major cities like Amsterdam, Copenhagen, Edinburgh, Helsinki, Oslo, Stockholm, London and St Petersburg would all be saved from devastating flooding. Is the NEED starting to make sense now? It’s actually just a colossal version of the kind of project that countries like the Netherlands have been working on for decades.
We mentioned the Afsluitdijk earlier. This massive seawall encloses the Zuiderzee, a saltwater inlet right here. Along with other projects like the Delta Works — a set of thirteen more dams, which close off other inlets — the Afsluitdijk helps to protect the Netherlands from the surging power of the North Sea.
Honestly, without these giant dams, the Netherlands would be much, much smaller. About a quarter of the country is below sea level. All that land would be underwater.
Sjoerd Groeskamp is Dutch, remember. And maybe… that isn't a surprise. Ocean seawalls are right at the heart of this country’s whole existence.
The Dutch have even managed to reclaim chunks of land with the help of their ocean defenses. After turning the Zuiderzee into a reservoir — just like NEED would do to the North Sea and the Baltic — they used pumping stations to drain away some of the water. Noordoostpolder, for example, is a municipality which was literally reclaimed from the waves.
Groeskamp’s paper on NEED doesn’t mention the idea of land reclamation. But some people have asked the question: could pumping stations be used here, too, to recover chunks of land? Thousands of years ago, parts of the North Sea were actually free of water.
If this land was claimed back, with the help of NEED, it could be used for things like food production. . .
Just to repeat: that’s not in the paper. Groeskamp only saw these dams as a solution to rising sea levels. But even without any land reclamation, the NEED is still a massive project.
As we mentioned earlier, the total length would be twenty times more than the Afsluitdijk. So maybe it’s time to ask a question. Is the NEED just a wild, impossible plan, or… Could this project actually be built?
In the words of Groeskamp: “NEED would be one of the largest civil-engineering challenges ever faced. ” To quote him, he firmly believes that this challenge is “substantial but surmountable. ” His paper explains what these seawalls would actually look like.
Not just the length, but also the general structure. Apparently, the tops would be 50 meters wide, and extend 20 meters above the ocean. That would act as a buffer against rising sea levels, not just in the next century, but beyond.
From there, the sides of these giant seawalls would slope to the ocean floor. These slopes are pretty standard for a seawall. The wider base helps to keep it stable, and the slopes can absorb any currents and waves much better than a vertical wall.
As for materials, these walls wouldn’t be complex. They’d mostly be made of sand, stone and clay. Having said that… one major challenge for NEED would be the amount of material required.
According to Groeskamp, it would take more than 50 billion tons of sand to build the entire project. Believe it or not, if you took all that sand and spread it on the ground, you’d have enough to cover the entire United Kingdom. That’s… a lot of sand.
But it’s actually not an impossible amount of material. 50 billion tons of sand are already collected, every single year, for construction projects all around the world. If it was possible to boost that current number by 10%, with some extra funding and larger operations, it would only take ten years or so to stockpile enough sand for NEED.
Another challenging aspect of NEED is the insane depth of the ocean floor. These walls will need to reach all the way from the surface of the ocean to the bottom. At their deepest points, that’s a stretch of just over 100 meters for NEED-south, and more than 300 meters for NEED-north, where it crosses this plunging stretch of ocean known as the Norwegian Trench.
Working at these depths is difficult, given the immense pressure of the water. But again — just like gathering all that sand — it wouldn’t be totally impossible. Groeskamp points out that the bases of oil rigs have been constructed at similar depths: “Although dams have different requirements than oil rigs, this is encouraging for the possibility of constructing NEED.
” One possible approach to deepsea construction is something called a caisson. It’s basically a giant concrete box full of sand or gravel, which a construction team can drop from a boat and sink to the bottom of the ocean. Caissons have been used for other seawalls in the past, just left to rest at the bottom of the sea like colossal concrete bricks.
Doing anything like this on the scale of NEED would be extremely challenging. And it would take a lot of time. Groeskamp gives an estimate of twenty years — but in interviews, he’s admitted that the entire project could potentially take closer to a century.
That wouldn’t be ideal. Not if we need this thing by 2100. But that century estimate is the worst case scenario.
It could probably be done much sooner. So could the NEED be built? Not easily.
But it wouldn’t be impossible. “so far, there’s not been a single engineer who has claimed that this is not possible”. Here’s another question, though: How much would the project cost?
According to Groeskamp — get ready for this — NEED could cost up to 550 billion euros, or 600 billion dollars. This eye watering figure is only an estimate, but it’s based on comparisons with other seawall projects, like the Saemangeum Seawall in Korea. That project cost roughly 2 billion dollars, and was significantly smaller and less difficult than NEED.
Apparently, NEED would cost hundreds of times as much. At first glance, 600 billion dollars sounds like an impossible amount of money. But it might be feasible.
As Groeskamp points out, this number wouldn’t feel quite so huge if the cost was shared by the fifteen countries that NEED is designed to protect. Let’s say that this project took that lower estimate of twenty years to build. If we spread the cost across those twenty years, we’d get 30 billion dollars per year.
And that number is less than 0. 5% of the combined GDP of those countries. That suddenly sounds more reasonable, right?
It’s still not ideal. Obviously. To raise that extra 0.
5%, those countries would need to bump their taxes, or make spending cuts in other areas. And it won’t be easy for a fair agreement to be drawn between the fifteen countries. Would all of those countries pay the same amount, or would the richest countries pay more?
How does Russia fit in, with its economic sanctions? And here’s the biggest question. Would these countries even want the NEED?
On top of the eye watering cost of the project, there are also some other… Problems with NEED …which we really need to talk about. First, these seawalls would have a massive impact on European trade from major ports. Any ships from cities like Rotterdam and Hamburg would find themselves trapped in the giant reservoir, unable to access commercial routes out across the wider ocean.
Some sluice gates could potentially be installed in the seawalls. But using these gates would be slower and less convenient than openwater travel. Imagine long queues of ships, like the ones you might see at the gates of a commercial canal.
And this slowdown would leave a massive dent in Europe’s maritime economy. NEED would also cause environmental issues. These seawalls would block the natural movement of currents, nutrients, sediment and marine life in and around the North Sea.
This could devastate local ecosystems, like the populations of whales and dolphins which rely on the North Sea for food. Then there’s the issue of desalination. These seawalls are designed to hold back seawater, but freshwater will still be entering the reservoir from rivers all across Europe.
Over time, this freshwater will dilute the reservoir. Within a hundred years, the North Sea could end up ten times less salty than today. This would of course heavily impact marine life.
And that isn’t only an environmental issue. It would also be a blow to the fishing industry — along with shipping disruption, that’s another hole in the European economy. So this is what the NEED would come with.
Ruined ecosystems… broken economies… eye watering total costs. But at the same time, what’s the alternative? Just to sit back and watch as the rising ocean forces millions to flee their homes?
That would also mess up ecosystems. That would also ruin economies. And when you put it like that, it’s hard to know which one is the better option.
But here’s the thing. These aren’t the only options. Global sea levels don’t actually have to rise.
At least, they don’t have to rise by the extreme levels that NEED is designed to cope with. According to a report by the United Nations, “How far the oceans rise will depend a great deal on what we do in the next few decades. ” If countries started taking more meaningful steps to reduce their emissions, that would totally change the situation.
In 2015, many global leaders signed the Paris Agreement: a pledge to lower emissions, and limit global warming to just 1. 5°C. We’re not currently on track to hit that target… but if countries tried harder to get on track, then sea level rise by 2100 could be kept as low as 28 centimeters.
And if the sea only rose by 28 centimeters? We wouldn’t need NEED at all. Actually… that’s the entire reason that Groeskamp wrote this paper.
Believe it or not, he doesn’t want to build NEED. He never wanted to build it. Instead, he wrote it as a warning to the wider world.
If we don’t take immediate climate action, then a few years from now, we’ll be forced to make some hard decisions. Hard decisions, like building giant seawalls that disrupt the whole of Europe. In one quote that we found on Groeskamp’s website: “If we need to build it, basically we’ve failed.
” It’s strange to see a scientist work so hard on a project, just to tell the world not to build it. But this is something he feels strongly about: What do you think? Will the NEED ever be built?
Let us know in the comments below. Thank you for watching, and if you enjoyed this video, why not check out this other one we made about a similar plan to dam the Mediterranean.
