A giant dam around the North Sea?

[pikaia]

"A Dutch government scientist has proposed building two mammoth dams to completely enclose the North Sea and protect an estimated 25 million Europeans from the consequences of rising sea levels as a result of global heating.

Sjoerd Groeskamp, an oceanographer at the Royal Netherlands Institute for Sea Research, said a 475km dam between north Scotland and west Norway and another 160km one between west France and south-west England was “a possible solution”.

https://www.theguardian.com/environment/2020/feb/12/giant-dams-could-protect-millions-from-rising-north-sea

I wonder if the enclosed sea level would actually stay put, with all the rivers flowing into it and all the rain falling on it?

[pietkuip]

I wonder if the enclosed sea level would actually stay put, with all the rivers flowing into it and all the rain falling on it?

It would need an awful lot of pumping: all the rivers, also those discharging in the Baltic Sea.

If it is possible to build it, if when it fails, it would do so catastrophically.

I guess the purpose of this "plan" is to make people realize that they are in big trouble.

[Tor Bejnar]

The Dutch know all about windmills and water pumping, and with the occasional Dutch lad sticking a finder in where it's needed, what could go wrong? [/sarc]
 

[pietkuip]

I just listened to a podcast by Rutger Bregman where he says that already Johan van Veen (1893 - 1959) had proposed to close off the North Sea between England and Norway.

https://en.wikipedia.org/wiki/Johan_van_Veen

[etienne]

Pumping should not be an issue, at low tide, it should be possible to remove enough water out of the bassin. But it should be an ecological catastrophe because tides might disappear inside the bassin, maybe salt density would decrease, animals (fishes, seals...) wouldn't be able to go around... Maybe it would reduce pollution entering in the atlantic.
And what if see level rises more than expected ?

[wili]

Besides all the other issues, why put the southern part near the widest section of the English Channel, rather than at the narrowest (Dover Straight) where it's only 34 k (21 m) wide?

I suppose you protect a lot more sea coast with their plan, but at what expense?

Most of the coasts of that part of Northern France and Southern England seem to rise pretty quickly from sea level (white cliffs of Dover, and all that), so I can't see that it gets them all that much...

[oren]

Another stupid, unfeasible idea. Covering the globe with solar panels and batteries and interconnects is cheaper, requires less cooperation, and provides an actual solution rather than a temporary local band-aid. If that is not done yet, why does anyone think this useless, dangerous dam will be built?

[gerontocrat]

Besides all the other issues, why put the southern part near the widest section of the English Channel, rather than at the narrowest (Dover Straight) where it's only 34 k (21 m) wide?

I suppose you protect a lot more sea coast with their plan, but at what expense?

The English Channel or Le Manche is the busiest sea lane in the world - 500 to 600 ships a day.

[pietkuip]

Another stupid, unfeasible idea. 

Sure. It is more a warning:

"Ultimately, the description of this extreme dam is more of a warning than a solution, Groeskamp states. ‘The costs and the consequences of such a dam are huge indeed. However, we have calculated that the cost of doing nothing against sea level rise will ultimately be many times higher. This dam makes it almost tangible what the consequences of the sea level rise will be; a sea level rise of 10 metres by the year 2500 according to the bleakest scenarios. This dam is therefore mainly a call to do something about climate change now. If we do nothing, then this extreme dam might just be the only solution.’"
https://www.nioz.nl/en/news/een-dam-dwars-door-de-noordzee-waarschuwscenario-voor-klimaatverandering

[wili]

ger, good point. But wouldn't that be an issue pretty much wherever along the English Channel you put it.

IIRC, similar plans are being considered for the Mediterranean Sea. I wonder how many other places are considering projects of this scale?

[pietkuip]

Pumping should not be an issue, at low tide, it should be possible to remove enough water out of the bassin.

I read some interviews (in Dutch) with the author, and he mentions the need of huge pumps. Low tide will not be low enough: out there in the Norwegian Sea, at the edge of the Atlantic, the tidal range is not large enough.

[pikaia]

Another problem is that it would require a huge amount of cement, and manufacturing it would generate a huge amount of CO2.

[oren]

Sure. It is more a warning:

Thanks for the explanation. In that regard it makes sense - if you will not do the logical thing, this is what you will have to resort to.

[NeilT]

It is so nice to know that these ideas throw the entirety of the western UK and  all of Ireland to the wolves so that the rest of the EU can be protected.....

Whilst the UK is quite used to this kind of thinking, I'd suggest the Irish might be justifiably miffed.

Any wall of this type should pass Northern Scotland and Western Ireland then bend back to France off the tip of Cornwall.

If they can't afford that, then they need to get on with fixing the climate issue.

[kassy]

Oh well someone got his 15 minutes of fame. Maybe now go back to literature and check if 10m by 2500 is still the worst case... 

[nanning]

I think pikaia mentioned an important side effect: Enormous extra emissions. We're in a global climate emergency situation and need to bend the curve fast.
A large part of the people of the Netherlands will become climate refugees in the future. It is coming. How soon? Dunno, probably this century. Where can they go to? Camp on the North Sea Dam?
Luctor et emergo.

[pietkuip]

We're in a global climate emergency situation and need to bend the curve fast.

But ice on Greenland and Antarctica will continue melting, whatever we do now. I do not think there will be much left of the Netherlands in the year 2300. It is likely to be as in the map sketch in this article: https://www.vn.nl/rising-sea-levels-netherlands/

[rboyd]

Geo-engineering gone insane, and as already stated the supposed "worst case" is not the worst case. Reminds me of King Canute.

https://en.wikipedia.org/wiki/King_Canute_and_the_tide

[blumenkraft]

Yeah, Rboyd, geoengineering ideas are inherently insane, but this one gets extra points for stupidity as well.