Proposed dam to protect NL, DE, DK, SE from rising sea levels

Edit: evidently the Hoover Dam is 379 meters long.

I guess blocking the sea access to Hamburg is also a no thanks for Germany.

The black line in Germany would cut off all of the shipping lanes and make gates and sluices necessary out there between the island chain. Where ground is totally unsuitable for that: The Wattenmeer is more of a tidal salt water swamp which goes out for tens of kilometers from the cost. Interrupted of course by deep cuts where the major rivers go out and shipping goes in. On the outer rim of the island chain, there is also a current along the coast that will make any major construction difficult, to say the least. Many islands struggle with that current reshaping them, for the most well-known example, see Sylt.

And before anyone says "well, they did it in the Netherlands", no, they didn't. The Ijsselmeer was a bay they cut off and drained, not an exposed coastline.

The realistic option (that is getting implemented over time) is just fortifying the existing dams. A few minor islands might cease to exist, but saving them won't be cost-effective.

The father of Deltaworks said “Eens zullen we ons land met een zucht van verlichting aan de golven prijsgeven.” "One day with a sigh of relief we will give up this country to the waves." Drastic solutions are required after sea level rise of 2m. So, maybe not this century but certainly the next one.

[1] https://www.delta.tudelft.nl/article/het-nieuwe-nederlandje-...

As sea levels rise, plans like this will get a lot more attention. These people are talking about dealing with five to ten meters of sea level increases. That's going to cause a lot of challenges that will require some serious engineering. And and it's unlikely that a country like the Netherlands is going to patiently await rising sea levels and do nothing about it. That's just not how things work over there and there's too much history of dealing successfully with similar challenges in the past.

My home country has of course a bit of a track record when it comes to building effective sea defenses. The Delta works are pretty awesome and cost many billions. The trigger point for deciding on building all that was some severe flooding in the 1950s. Thousands died, and the sea pushed deep into the country. Basically, engineers went to work and started coming up with plans to prevent that from happening again. Implementing this took decades. The work was only completed in the nineties.

The end result is a system of of dikes, sluices, and other defenses that seem very effective so far. And a lot of know how for building stuff like this. Which is why e.g. Dubai has some nice new valuable offshore real estate in the form of a few nice new islands. Skills like that are going to be in demand a lot in the next decades as different countries figure out that they can either accept losing major chunks of their coastal real estate or try doing something about it. And that is going to unlock a lot of financing.

So, yes, plans like this sound like the right level of ambition at least. Too early to tell if this specific one will win. But something will happen.

“Ah, sure fuck Ireland (and the west coast of the UK) anyway”

Apparently, the pulses that bring in saline water (along with more oxygen-rich water) into the Baltic Sea have been getting less frequent in recent decades. They still happen, though.

It seems outlandish that anybody would write about such an idea (or the damming of the Baltic Sea part of it) without even mentioning that. It sounds like a crazy engineering idea with no real regard for side effects.