11 ms·

Seaflooding

322 points by deegles 3y ago

villgax 3y ago
Just reading this title made me suddenly think of wanting to live under the ocean/sea(closer to land albeit) like Sandy from SpongeBob. Affordable housing for all I guess.
Gys 3y ago
Very interesting article. I like the idea of re-filling old dried out seas. Not much can go wrong (on first look), its doable and the benefits can be huge.
- lostlogin 3y ago
  > not much can go wrong The article says “ And with such a big new sea in a hot desert, a lot of its water would evaporate. This is good, because it would increase the amount of water being pumped in—generating more electricity—and it would increase the local moisture, which could increase local rainfall.” Adding a ton of water to the atmosphere is going to cause rain. This may be mostly good but in a hot environment it could week be absolutely incredible downpours.
  - brutusborn 3y ago
    Downpours would have to be monsoon level before this caused problems. A new lake causing monsoon level rain? I doubt it but I've been surprised before.
  - sambeau 3y ago
    Adding a ton of water to the atmosphere is going to cause more warming. Water vapour is Earth's most abundant greenhouse gas. It's responsible for about half of Earth's greenhouse effect.
    - lproven 3y ago
      It is vital to consider proportion: 2/3 of the Earth is ocean. These new seas would be absolutely tiny by comparison. The extra water vapour added to the atmosphere would be a rounding error. Unfortunately the same applies to the amount of sea level rise they offset: it too would be a rounding error, a fraction of a percent.
      - lostlogin 3y ago
        > Unfortunately the same applies to the amount of sea level rise they offset: it too would be a rounding error, a fraction of a percent. Flooding Flood the Qattara Depression would lower the sea level by 3mm according to the article.
        lproven 3y ago
        Yes... which is less than the current annual increase of 3.4mm: https://sealevel.nasa.gov/faq/8/is-the-rate-of-sea-level-rise-increasing/ https://sealevel.nasa.gov/faq/8/is-the-rate-of-sea-level-ris... The West Anarctic Ice Sheet alone will cause ~3.3m rise when it collapses. https://www.carbonbrief.org/guest-post-how-close-is-the-west-antarctic-ice-sheet-to-a-tipping-point/ https://www.carbonbrief.org/guest-post-how-close-is-the-west... Note, NOT melts; just when it breaks up and floats away, still frozen. That one ice sheet, currently cracking, is over half resting on rock that is way below sea level. Some is 2000m under sea level. It doesn't need to melt, it just needs to break off and float away. That would cause a 3.5-5m *depending on ow much floated) increase in mean sea level, worldwide, in approximately 12 days. That is over 1000x time the reduction caused by flooding the Qattara depression. Or 0.1% -- or as I said, a fraction of a per cent.
    - keyle 3y ago
      Unlikely to be important, compared to the creation of irrigation and additional plants and greenery that generates O2 and absorbs CO2?
    - throwaway290 3y ago
      Before someone reading this thinks that drying up the planet would cool it down: water in the air acts as a greenhouse gas, but also cools the surface when it evaporates and helps reflect solar radiation when it forms clouds (major factor of our planet's albedo). Also we are not comparing more water area vs less water area. Water will take more area in any case as sea levels rise. This way it just happens in a bit more controlled way.
EdwardDiego 3y ago
> So why not play a Zanclean and flood it with water from the sea? Why not? Because we're _really bad_ at modelling all possible outcomes, especially when it comes to large scale engineering projects.
- brutusborn 3y ago
  There's always a chance it has downsides, but worst case you block the canal and it turns back into a dead sea. I would say we are excellent at modelling outcomes, just bad at listening to models that tell us what we don't want to hear. For example, we knew about global warming before computers existed. The model and the tech wasn't the problem, human avoidance of bad news was (and is). We can't just avoid doing everything because our models might be wrong. I find that reasoning repulsive. If humanity took that approach we would have died long ago.
  - EdwardDiego 3y ago
    I figure we've had enough examples of well-meant interventions that lead to worse outcomes to be really conservative about "just change the ecosystem and heat/salinity circulation patterns of two large bodies of water, what's the worst that could happen?"
    - joshuanapoli 3y ago
      We should be able to extrapolate from the large-scale reservoirs that have already been built. The proposed reservoirs would be 10x larger, so there would undoubtedly be learnings. But we would probably build such projects in stages, so that the project could be stopped or altered if the effect is negative.
      - throwaway173738 3y ago
        You’re assuming linearity and arguing that all things are equal. I would be surprised if either of those things are true.
    - 3y ago
h4kor 3y ago
One major consequence of flooding Saharan basins could be the death of the Amazonas rain forest, as it depends on Saharan dust. https://www.youtube.com/watch?v=ygulQJoIe2Y https://www.youtube.com/watch?v=ygulQJoIe2Y
- brutusborn 3y ago
  I doubt it, the Qattara Depression is a fraction of the size of the Sahara. Marginally less fertile? Probably. Dead? No chance.
  - h4kor 3y ago
    As I understood it, the Sahara is not a stable system and can relatively easily be greened again.
euroderf 3y ago
Dress up the Dead Sea project to attract tourism, and Israeli/Jordanian co-operation will find a way.
NKosmatos 3y ago
Very interesting article and the whole idea of controlled sea flooding is well founded, but international geopolitics for sure is a major obstacle.
- lproven 3y ago
  Some north African countries are very large, because they are mostly desert, which is a little inherent value, except perhaps for buried mineral resources. Therefore, some of these projects could be entirely within the boundaries of one nation.
aww_dang 3y ago
Ideally a sea level canal situation would allow for tidal forces to regulate salinity. The added bonus would be in shipping. I'm not a civil engineer, but the idea that you can constantly generate hydroelectric power while desalinating with the derived electricity seems problematic. https://energycentral.com/c/pip/great-mexicali-energy-and-shipping-canal https://energycentral.com/c/pip/great-mexicali-energy-and-sh...
- desas 3y ago
  Shipping to where exactly? How lucrative is the middle of the Sahara desert market?
alex_duf 3y ago
This feels like an over-simplification of the benefits. I have yet to be convinced that filling an area with salted water, which by evaporating will only increase the salt concentration, can host a thriving ecosystem. I'm also having trouble buying the argument that to lower the salt concentration we can extract it and sell the salt. Sure we can, but are talking about the same scale here? Moreover, it may look like a hostile place, but I'm sure that in all the examples given there are populations there, maybe nomadic, and there are organisms that live there. Finally, I find it interesting than when illustrating the Quattara seat, the author has added green around it, but I see no reason for that greening to be there at all when a few hundred kilometres north on the border of the current Mediterranean sea there's nothing. After all, same region, roughly same altitude, same water, but even higher salt concentration. So yeah, I love the futurism aspect of the article, it makes me dream of a techno-solution, but I remain unconvinced though I'd love to be wrong.
- konschubert 3y ago
  > I'm also having trouble buying the argument that to lower the salt concentration we can extract it and sell the salt. Sure we can, but are talking about the same scale here? Besides, this is not economical.
- throwaway290 3y ago
  > I see no reason for that greening to be there at all when a few hundred kilometres north on the border of the current Mediterranean sea there's nothing. Northern Africa is dry now, but as the north warms up this may actually change (https://www.forbes.com/sites/trevornace/2017/11/09/northern-africa-driest-places-earth/ https://www.forbes.com/sites/trevornace/2017/11/09/northern-...). > I'm sure that in all the examples given there are populations there Which should benefit from this the most. > there are organisms that live there. I just don't get the argument. Are you worried about some organisms in one of the least hospitable places? Some organisms that may live there and thrive in dry salt, but not if it was wet? What makes you specifically worried about those organisms that you dislike the potential for more and more diverse organisms if it was a sea instead of salty sand?
  - 3y ago
Neil44 3y ago
I feel like the general mood is too risk averse for big projects like this at the moment. I hope I'm proved wrong though. I miss an age of optimism.
- baggy_trough 3y ago
  The Age of Optimism declined due to observed results.
  - Neil44 3y ago
    I don't think long term pessimism has amazing results either.
    - svnt 3y ago
      It isn’t binary. Naive optimism and over-agency in a natural system seems to primarily function to bring information to the agent at the cost of system performance. If what is here called pessimism results in the down-regulation of human impact and us largely getting out of the way of self-equilibrium-finding complex systems until we better understand them, then prudence very well might have amazing results.
      - Neil44 3y ago
        That the systems are equilibrium finding and that said equilibrium will be ‘amazing’ are both quite bold assumptions.
ecology 3y ago
at glance, if i divide the area of those deserts to the surrounding larger seas ... the ratio looks very small, maybe < .1% or much less (don't have numbers) a drop in the ocean
petesergeant 3y ago
The article seems to presuppose that being near a big amount of salt water will cause frequent rain, but the coastline of most of North Africa and the Arabian peninsula suggests otherwise.
- lproven 3y ago
  Ocean currents are often cold. Cold water doesn't evaporate so readily. Small, relatively shallow inland seas will be relatively warm; as such, they will evaporate readily.
  - petesergeant 3y ago
    Persian Gulf gets up to 32-34C in summer. How hot exactly are your proposed inland seas?
    - lproven 3y ago
      It is also quite small, though... hardly open ocean, and almost isolated by the Straits of Hormuz (?) from the ocean, so probably not much affected by deep sea currents, no?
      - petesergeant 3y ago
        Yes, but I'd say this further supports my assertion, given that rain is unusual on the Arab peninsula despite it being surrounded by warmer water
        lproven 3y ago
        That is a fair point. :-) The topography might be an issue, but still... touché.
- rtpg 3y ago
  I do not know much but a guess: air currents over oceans mean evaporated water doesn’t stick around as much as with rivers or lakes? Though I share your skepticism with the hand-wavy “mo water mo rain”
dvh 3y ago
Or make Czech reservoir: https://prehrada.hrach.eu/en.html https://prehrada.hrach.eu/en.html
- BurningFrog 3y ago
  I don't think inland seas will affect ocean levels?
- FlyingSnake 3y ago
  I am sure the people living in Czechia will not like to live underwater.
  - rhubinak 3y ago
    It will solve the housing crisis...
- Jenda_ 3y ago
  Someone suggested a better project for Hungary (and surrounding countries): https://www.abclinuxu.cz/images/screenshots/1/0/250401-pouziti-topografickych-dat-srtm-ceska-prehrada--3961472512209963872.jpg https://www.abclinuxu.cz/images/screenshots/1/0/250401-pouzi... It requires only a small dam near Golubac.
detritus 3y ago
I used to dream of large scale solar and nuclear-powered desalination plants lining the mediterranean, solely for the purpose of pumping inland to create fresh water lakes to cool the local environment and perhaps stymie the increasing desertification of thre Iberian peninsula further north. Then I grew up a bit and realised how mind-bogglingly massive such a scheme would have to be :) These seems like a far more likely possibility, given the scale. Given we might be in part historically responsible for a lot of the desertification around the periphery of the Med, I don't personally have major qualms about geo-engineering 'mostly useless' spaces back into something a little more fertile and a little cooler.
- pif 3y ago
  > and perhaps stymie the increasing desertification of thre Iberian peninsula I think I get your point. I'm ready to take huge risks in order to support anything that may weaken the permanent African anticyclone.
  - detritus 3y ago
    Hmm, where were you and your keen insight thirty years ago to pour cold water on my adolescent mental machinations around helping dissuade creeping desertation around where i lived?
    - pif 3y ago
      I was in Southern Italy, suffering for a weather that did not correspond to what I read in my school books, and learning to hate the words "Azores anticyclone". And later I switched to yearning for the comparatively friendly Azores anticyclone every time the damned African anticyclone came uninvited to the heart of the Mediterranean Sea, and made itself at home for weeks at a time.
      - detritus 3y ago
        My partner's from Marche, and boy do they have a bit too much water at the moment... :/
ggm 3y ago
Not a fan of geo-engeering when it's the "sulfur dioxide sunscreen" trick, or iron fertiliser in the sea. This one I'm sure has side effects, but seems marginally more plausible.
spuz 3y ago
This reminds me of the Salton Sea, a man-made lake in California which used to be promoted as a tourist destination and now continues to be an ecological disaster. https://en.wikipedia.org/wiki/Salton_Sea https://en.wikipedia.org/wiki/Salton_Sea
- ZeroGravitas 3y ago
  There is a similar "seaflooding" plan for that sea, and it is mentioned in passing at the end of the list of possible global sites in the article. https://www.latimes.com/california/story/2022-10-05/panel-rejects-idea-of-filling-salton-sea-with-ocean-water https://www.latimes.com/california/story/2022-10-05/panel-re...
  - CommieBobDole 3y ago
    An issue with flooding the Salton Sea to sea level is you'd submerge a lot of agricultural land that already exists to the north and south of the Sea. Plus a number of towns (like Coachella) that already exist in the area. Though, if you could use this to maintain the water level and salinity at historical levels, you could avert the ecological disaster that's going to happen when the Salton Sea dries up. And it would likely become a popular area for recreation again, like it was in the 1950s and 60s.
    - bradleyjg 3y ago
      you'd submerge a lot of agricultural land that already exists to the north and south of the Sea Thus solving, or at least significantly migrating, the Colorado river over allocation problem. Win-win.
- AbrahamParangi 3y ago
  To be fair, it was accidentally created and so its water was intentionally cut off, causing the current ecological mess - which by the way also applies to other dried salt lakes too.
  - 3y ago
thomasfromcdnjs 3y ago
I'd wager that "Seaflooding" will just happen somewhere anyway, likely some where we ain't really looking. And it will be fine. Mankind has seemingly surpassed weather patterns, and it now the 21st century.
x-complexity 3y ago
Any talks of flooding anywhere with water/sea just remind me of the "Flood Ohio" meme, both in terms of practicality & humour: https://www.youtube.com/watch?v=O4BPxKhRJRo https://www.youtube.com/watch?v=O4BPxKhRJRo
jeroenhd 3y ago
The idea of the Qattara sea is fascinating. On paper, it sounds so easy: dig a long trench and let nature run its course. There's so little life in the Sahara and there's so much Sahara around the theoretical sea that the ecological impact would be quite small for such a huge undertaking. With global temperatures continuing to rise and humanity preferring short-term profit over long-time survival, cooling even just a little bit of the Sahara could significantly extend the time people can live in northern Africa. I doubt we'll see the resurgence of the Green Sahara any time soon (the last period that kickstarted humanity in northern Africa was during an ice age, we're in the exact opposite situation of that) but even just a little bit of green and cool land in the desert could help a lot of people. Salinity would need to be kept in check, of course, but with a corridor big enough for tides to flow between the Mediterranean and the new sea there should be a quite manageable maximum salinity. Until that happens, we could harvest osmotic power ("blue energy") from the water stream, as fresher water will rush into the salt water reservoirs if we do not allow the minerals to flow back. Furthermore, with the new agricultural opportunities there need to be strict (and well-enforced) laws regarding pesticides and other types of contaminants to prevent another Lake Salton. With the current lack of agricultural possibilities in the area, this may actually be achievable if the government can see the long term benefits. It all sounds so incredibly doable. I don't think it'll ever happen because of politics and economics, and even if the project does get started I doubt it'll be long until the various terrorist groups active in northern Africa will find a new location to make the world a worse place, but I'm still very curious about what kind of world such projects could create.
- pbmonster 3y ago
  > Salinity would need to be kept in check, of course, but with a corridor big enough for tides to flow between the Mediterranean and the new sea there should be a quite manageable maximum salinity. First of all, this is not what the OP is suggesting. OP is using pipelines and wants to generate electricity from the potential energy. And for good reasons: between the suggested Qattara sea and the Med, there sits El Diffa square in the way. Which is 200m above sea level. You could tunnel that with a pipeline. Trenching that for a channel would be quite the project. Secondly, the Med only has a tidal range of 50cm. Using that to move a significant amount of water along a 100+km canal needs a truly humongous channel cross section. OP suggests using electricity to desalinate his sea. This would take insane amounts of energy, creating freshwater from desalination at the rate its evaporating across thousands of square kilometers in the Sahara takes orders of magnitude more power than the power station is going to generate. He also suggests using salt extraction pools. This only work, if rainfall creates fresh water rivers feeding his sea. Otherwise the water evaporating from this pool is lost to the sea, meaning you can only ever (at best) keep the salinity constant, but never decrease it. I think it's best to face it from the beginning: we're creating another Dead Sea. Salinity will prohibit life in the water and directly at the shore. Rainfall might make it possible away from the shoreline. But there will be absolutely no algae, shrimp or flamingos.
nickdothutton 3y ago
I’ve often wondered why we havent attempted something similar before. After all we have successfully drained the fens (in the 1600s, took only 7 years), constructed the hoover dam (1931, took 5 years), plus a dozen other significant geoengineering projects. There seems now to be a prevailing sentiment that geoengineering=bad among the general population.
aaron695 3y ago
[dead]
mkj 3y ago
If the climate-change induced sea level rise needs 1-2 metres of mitigation, and you have 100-200 metre deep depressions, you need to cover 1% of the Earth's surface (total, not just land) with these seafloods. Doesn't seem like a plausible mitigation, I'm puzzled why the article proposed it. The other benefits might be interesting locally some places.
- jacobr1 3y ago
  A few considerations: 1) you don't need to fully mitigate the sea-level rise for this to be of value. Even a few cm might make a difference on the margin for certain areas. 2) The projects themselves might be a value if we really could increase the productive value of currently arid parts of the land with net-positive environmental impact, so the sea-level rise doesn't matter or let's us do the project without worrying about sea-level drop. If we really had too-cheap-to-meter power for desalinization, then these projects might start to make sense, but it seems too soon to me.
culebron21 3y ago
The story seems so nice, but maths and observations on Quattara basin don't add up. First of all, climate around seas in deserted areas isn't much better than further in land. See the shores in Saudi Arabia, Dubai and Iran. But let's suppose someone decides to build the pipe and extract energy. It means one has to build a 58 km pipe under the ground (which is doable, like Gothard base tunner in Switzerland). Then, 4 issues remain: 1) you must treat the water coming in the pipes, because it's possible to clog the pipe, the turbine, etc. 2) what inclination do you need to get a reasonable discharge of water? 3) how much power one can extract from the flow? Rough estimates give me several megawatts per 10 m of elevation per 1 pipe of 10 m in diameter (this is the kind of size in new large-diameter tunnels). Seems like a lot of piping for not much power. 4) Erosion of the shores that may fill the basin up. This is what happens to natural lakes on plains. And key issue here: the more you discharge through the pipe, the higher the level of water in the lake, the less energy you can extract.
- enedil 3y ago
  Well, the air in Dubai is much more humid than in Riyadh (this is based on personal observation).
  - culebron21 3y ago
    Does it feel better in Dubai than in Riyadh?
- mnw21cam 3y ago
  2) The Romans used an inclination of 1:1000. The Quattara basin is 80km from the Mediterranean and 60m lower. So it's not looking good straight away. As the water level rises, the drop will be even less. Also, the amount of water that can evaporate from such a large area is immense, so you'd have to have a rather huge channel for the water coming in just to keep up.
  - zymhan 3y ago
    The romans were using gravity to move the water "for free". Using gravity to generate electricity is a different concept.
rtpg 3y ago
For a more nuanced view on the Egypt project in particular check the wiki page [0] Short version is it sounds uneconomical for power generation. Hard to believe but reading between the lines it feels like despite all the “free” hydroelectric you’re looking at immense construction difficulties You know your projects heading for the drawer when you propose using 100 atomic bombs to dig the tunnel [0] https://en.m.wikipedia.org/wiki/Qattara_Depression_Project https://en.m.wikipedia.org/wiki/Qattara_Depression_Project PS I’d love for this project to work. The main thing I could not really find supporting evidence for is “water will fill with life”. Just like… you could be constantly desalinating (and now have a brine problem) and still not really have a great ecosystem form I feel like? But I don’t understand this.
- sampo 3y ago
  That Wikipedia page talks about digging a 60 meters deep canal, not boring a tunnel.
FlyingSnake 3y ago
What are the 2nd and 3rd order effects that we're missing? Qattara depression lies in the Horse Latitudes that is full of arid deserts. So there's a high chance that flooding it might not make it turn into a lush wonderland. It could even end up being another dead sea. 1: https://oceanservice.noaa.gov/facts/horse-latitudes.html https://oceanservice.noaa.gov/facts/horse-latitudes.html
jjk166 3y ago
https://en.wikipedia.org/wiki/Salton_Sea https://en.wikipedia.org/wiki/Salton_Sea
julienchastang 3y ago
Did anyone else notice the beautiful photography contained in this post? Unfortunately, after a quick scan, I could not find any attributions to the photos.
- oh_sigh 3y ago
  Some of them are stock photos from Getty. The map at the top is from one of sorgel's exhibitions for atlantropa, though I'm not sure if it his own design or something put together by another artist for the exhibition
deepsun 3y ago
> This would reduce global warming No, water albedo is lower than Sahara desert, so it would capture more of the Sun's energy, and warm the planet.
hok 3y ago
Drying the Mediterranean Sea is surely a bad idea, but I wonder why nobody ever built hydroelectric generators into the Strait of Gibraltar. There is a huge steady flow of surface water from the Atlantic into the Mediterranean (1 million cubic meters per second), and almost as much flows back into the Atlantic in deeper layers. Why not tap into these streams to generate electricity?
- desas 3y ago
  Tidal energy is expensive - sea water is very corrosive and under water maintenance access isn't cheaply solved. Also you need to retain access for ships and subs. The UK has the second highest tidal ranges in the world and is probably a world leader, we still generate nearly no energy from tidal.
senkora 3y ago
Out of curiosity, I checked what the air pressure would be in a drained Mediterranean, since the article claimed it would be oppressively high. The average depth of the Mediterranean is 1.5km [1] which is less than 2.0km which would be a pressure of 130.069kPa vs 101.312kPa at sea level [2]. This seems fine? [1]: https://en.m.wikipedia.org/wiki/Mediterranean_Sea https://en.m.wikipedia.org/wiki/Mediterranean_Sea [2]: https://www.physicsforums.com/threads/air-pressure-below-sea-level.640478/ https://www.physicsforums.com/threads/air-pressure-below-sea...
- topaz0 3y ago
  It wouldn't crush you or anything, but it would be notable. Just like the difference between sea level and 2km above sea level is quite notable.
ajuc 3y ago
The article complains that places under the sea level have higher pressure and are "hell on Earth" because of that. Dead sea coast(currently lowest on-land point on Earth) has a higher pressure because of that, and it's beneficial for human health, it's a health resort. The article seems to contradict itself (like the proposal to add water to salt so that we can evaporate the water and sell the salt :) ), and seems to be highly subjective and dishonest.
gmuslera 3y ago
People usually mentions sea rise as the worst outcome of global warming, but extreme weather may be more pervasive, and that may be experienced far earlier than the sea level rise. In any case, this is at best a mitigation, not a solution. It sounds like a simple enough idea, and may not have as a disruptive impact as other geoengineering proposals that may end having unexpected consequences. Some of the proposed flooded areas could have unique ecosystems that may be negatively impacted, but anyway all ecosystems are being negatively impacted right now, so a delay in the very bad trends we might be in could be positive overall.
yawpitch 3y ago
We are just about to force future generations to (quite likely not) live through the unintended consequences of current and past generations ignorantly and recklessly engineering their environment out of a misguided desire “[grow] the economy, and [make] money along the way”, and in response the author seems to suggest we use more ignorance and recklessness to drive even more unintended consequences? We don’t want to lose deserts and more than we wanted to lose forests and wetlands (and are now desperately trying to save them)… just because humans are too stupid to see the complex reasons why specific ecosystems exist doesn’t mean they should KEEP acting on that stupidity.

322 points by deegles 3y ago

Just reading this title made me suddenly think of wanting to live under the ocean/sea(closer to land albeit) like Sandy from SpongeBob. Affordable housing for all I guess.

Gys 3y ago

Very interesting article. I like the idea of re-filling old dried out seas. Not much can go wrong (on first look), its doable and the benefits can be huge.

lostlogin 3y ago
> not much can go wrong The article says “ And with such a big new sea in a hot desert, a lot of its water would evaporate. This is good, because it would increase the amount of water being pumped in—generating more electricity—and it would increase the local moisture, which could increase local rainfall.” Adding a ton of water to the atmosphere is going to cause rain. This may be mostly good but in a hot environment it could week be absolutely incredible downpours.
- brutusborn 3y ago
  Downpours would have to be monsoon level before this caused problems. A new lake causing monsoon level rain? I doubt it but I've been surprised before.
- sambeau 3y ago
  Adding a ton of water to the atmosphere is going to cause more warming. Water vapour is Earth's most abundant greenhouse gas. It's responsible for about half of Earth's greenhouse effect.
  - lproven 3y ago
    It is vital to consider proportion: 2/3 of the Earth is ocean. These new seas would be absolutely tiny by comparison. The extra water vapour added to the atmosphere would be a rounding error. Unfortunately the same applies to the amount of sea level rise they offset: it too would be a rounding error, a fraction of a percent.
    - lostlogin 3y ago
      > Unfortunately the same applies to the amount of sea level rise they offset: it too would be a rounding error, a fraction of a percent. Flooding Flood the Qattara Depression would lower the sea level by 3mm according to the article.
      - lproven 3y ago
        Yes... which is less than the current annual increase of 3.4mm: https://sealevel.nasa.gov/faq/8/is-the-rate-of-sea-level-rise-increasing/ https://sealevel.nasa.gov/faq/8/is-the-rate-of-sea-level-ris... The West Anarctic Ice Sheet alone will cause ~3.3m rise when it collapses. https://www.carbonbrief.org/guest-post-how-close-is-the-west-antarctic-ice-sheet-to-a-tipping-point/ https://www.carbonbrief.org/guest-post-how-close-is-the-west... Note, NOT melts; just when it breaks up and floats away, still frozen. That one ice sheet, currently cracking, is over half resting on rock that is way below sea level. Some is 2000m under sea level. It doesn't need to melt, it just needs to break off and float away. That would cause a 3.5-5m *depending on ow much floated) increase in mean sea level, worldwide, in approximately 12 days. That is over 1000x time the reduction caused by flooding the Qattara depression. Or 0.1% -- or as I said, a fraction of a per cent.
  - keyle 3y ago
    Unlikely to be important, compared to the creation of irrigation and additional plants and greenery that generates O2 and absorbs CO2?
  - throwaway290 3y ago
    Before someone reading this thinks that drying up the planet would cool it down: water in the air acts as a greenhouse gas, but also cools the surface when it evaporates and helps reflect solar radiation when it forms clouds (major factor of our planet's albedo). Also we are not comparing more water area vs less water area. Water will take more area in any case as sea levels rise. This way it just happens in a bit more controlled way.

EdwardDiego 3y ago

> So why not play a Zanclean and flood it with water from the sea? Why not? Because we're _really bad_ at modelling all possible outcomes, especially when it comes to large scale engineering projects.

brutusborn 3y ago
There's always a chance it has downsides, but worst case you block the canal and it turns back into a dead sea. I would say we are excellent at modelling outcomes, just bad at listening to models that tell us what we don't want to hear. For example, we knew about global warming before computers existed. The model and the tech wasn't the problem, human avoidance of bad news was (and is). We can't just avoid doing everything because our models might be wrong. I find that reasoning repulsive. If humanity took that approach we would have died long ago.
- EdwardDiego 3y ago
  I figure we've had enough examples of well-meant interventions that lead to worse outcomes to be really conservative about "just change the ecosystem and heat/salinity circulation patterns of two large bodies of water, what's the worst that could happen?"
  - joshuanapoli 3y ago
    We should be able to extrapolate from the large-scale reservoirs that have already been built. The proposed reservoirs would be 10x larger, so there would undoubtedly be learnings. But we would probably build such projects in stages, so that the project could be stopped or altered if the effect is negative.
    - throwaway173738 3y ago
      You’re assuming linearity and arguing that all things are equal. I would be surprised if either of those things are true.
  - 3y ago

h4kor 3y ago

One major consequence of flooding Saharan basins could be the death of the Amazonas rain forest, as it depends on Saharan dust. https://www.youtube.com/watch?v=ygulQJoIe2Y https://www.youtube.com/watch?v=ygulQJoIe2Y

brutusborn 3y ago
I doubt it, the Qattara Depression is a fraction of the size of the Sahara. Marginally less fertile? Probably. Dead? No chance.
- h4kor 3y ago
  As I understood it, the Sahara is not a stable system and can relatively easily be greened again.

euroderf 3y ago

Dress up the Dead Sea project to attract tourism, and Israeli/Jordanian co-operation will find a way.

NKosmatos 3y ago

Very interesting article and the whole idea of controlled sea flooding is well founded, but international geopolitics for sure is a major obstacle.

lproven 3y ago
Some north African countries are very large, because they are mostly desert, which is a little inherent value, except perhaps for buried mineral resources. Therefore, some of these projects could be entirely within the boundaries of one nation.

aww_dang 3y ago

Ideally a sea level canal situation would allow for tidal forces to regulate salinity. The added bonus would be in shipping. I'm not a civil engineer, but the idea that you can constantly generate hydroelectric power while desalinating with the derived electricity seems problematic. https://energycentral.com/c/pip/great-mexicali-energy-and-shipping-canal https://energycentral.com/c/pip/great-mexicali-energy-and-sh...

desas 3y ago
Shipping to where exactly? How lucrative is the middle of the Sahara desert market?

alex_duf 3y ago

This feels like an over-simplification of the benefits. I have yet to be convinced that filling an area with salted water, which by evaporating will only increase the salt concentration, can host a thriving ecosystem. I'm also having trouble buying the argument that to lower the salt concentration we can extract it and sell the salt. Sure we can, but are talking about the same scale here? Moreover, it may look like a hostile place, but I'm sure that in all the examples given there are populations there, maybe nomadic, and there are organisms that live there. Finally, I find it interesting than when illustrating the Quattara seat, the author has added green around it, but I see no reason for that greening to be there at all when a few hundred kilometres north on the border of the current Mediterranean sea there's nothing. After all, same region, roughly same altitude, same water, but even higher salt concentration. So yeah, I love the futurism aspect of the article, it makes me dream of a techno-solution, but I remain unconvinced though I'd love to be wrong.

konschubert 3y ago
> I'm also having trouble buying the argument that to lower the salt concentration we can extract it and sell the salt. Sure we can, but are talking about the same scale here? Besides, this is not economical.
throwaway290 3y ago
> I see no reason for that greening to be there at all when a few hundred kilometres north on the border of the current Mediterranean sea there's nothing. Northern Africa is dry now, but as the north warms up this may actually change (https://www.forbes.com/sites/trevornace/2017/11/09/northern-africa-driest-places-earth/ https://www.forbes.com/sites/trevornace/2017/11/09/northern-...). > I'm sure that in all the examples given there are populations there Which should benefit from this the most. > there are organisms that live there. I just don't get the argument. Are you worried about some organisms in one of the least hospitable places? Some organisms that may live there and thrive in dry salt, but not if it was wet? What makes you specifically worried about those organisms that you dislike the potential for more and more diverse organisms if it was a sea instead of salty sand?
- 3y ago

Neil44 3y ago

I feel like the general mood is too risk averse for big projects like this at the moment. I hope I'm proved wrong though. I miss an age of optimism.

baggy_trough 3y ago
The Age of Optimism declined due to observed results.
- Neil44 3y ago
  I don't think long term pessimism has amazing results either.
  - svnt 3y ago
    It isn’t binary. Naive optimism and over-agency in a natural system seems to primarily function to bring information to the agent at the cost of system performance. If what is here called pessimism results in the down-regulation of human impact and us largely getting out of the way of self-equilibrium-finding complex systems until we better understand them, then prudence very well might have amazing results.
    - Neil44 3y ago
      That the systems are equilibrium finding and that said equilibrium will be ‘amazing’ are both quite bold assumptions.

ecology 3y ago

at glance, if i divide the area of those deserts to the surrounding larger seas ... the ratio looks very small, maybe < .1% or much less (don't have numbers) a drop in the ocean

petesergeant 3y ago

The article seems to presuppose that being near a big amount of salt water will cause frequent rain, but the coastline of most of North Africa and the Arabian peninsula suggests otherwise.

lproven 3y ago
Ocean currents are often cold. Cold water doesn't evaporate so readily. Small, relatively shallow inland seas will be relatively warm; as such, they will evaporate readily.
- petesergeant 3y ago
  Persian Gulf gets up to 32-34C in summer. How hot exactly are your proposed inland seas?
  - lproven 3y ago
    It is also quite small, though... hardly open ocean, and almost isolated by the Straits of Hormuz (?) from the ocean, so probably not much affected by deep sea currents, no?
    - petesergeant 3y ago
      Yes, but I'd say this further supports my assertion, given that rain is unusual on the Arab peninsula despite it being surrounded by warmer water
      - lproven 3y ago
        That is a fair point. :-) The topography might be an issue, but still... touché.
rtpg 3y ago
I do not know much but a guess: air currents over oceans mean evaporated water doesn’t stick around as much as with rivers or lakes? Though I share your skepticism with the hand-wavy “mo water mo rain”

dvh 3y ago

Or make Czech reservoir: https://prehrada.hrach.eu/en.html https://prehrada.hrach.eu/en.html

BurningFrog 3y ago
I don't think inland seas will affect ocean levels?
FlyingSnake 3y ago
I am sure the people living in Czechia will not like to live underwater.
- rhubinak 3y ago
  It will solve the housing crisis...
Jenda_ 3y ago
Someone suggested a better project for Hungary (and surrounding countries): https://www.abclinuxu.cz/images/screenshots/1/0/250401-pouziti-topografickych-dat-srtm-ceska-prehrada--3961472512209963872.jpg https://www.abclinuxu.cz/images/screenshots/1/0/250401-pouzi... It requires only a small dam near Golubac.

detritus 3y ago

I used to dream of large scale solar and nuclear-powered desalination plants lining the mediterranean, solely for the purpose of pumping inland to create fresh water lakes to cool the local environment and perhaps stymie the increasing desertification of thre Iberian peninsula further north. Then I grew up a bit and realised how mind-bogglingly massive such a scheme would have to be :) These seems like a far more likely possibility, given the scale. Given we might be in part historically responsible for a lot of the desertification around the periphery of the Med, I don't personally have major qualms about geo-engineering 'mostly useless' spaces back into something a little more fertile and a little cooler.

pif 3y ago
> and perhaps stymie the increasing desertification of thre Iberian peninsula I think I get your point. I'm ready to take huge risks in order to support anything that may weaken the permanent African anticyclone.
- detritus 3y ago
  Hmm, where were you and your keen insight thirty years ago to pour cold water on my adolescent mental machinations around helping dissuade creeping desertation around where i lived?
  - pif 3y ago
    I was in Southern Italy, suffering for a weather that did not correspond to what I read in my school books, and learning to hate the words "Azores anticyclone". And later I switched to yearning for the comparatively friendly Azores anticyclone every time the damned African anticyclone came uninvited to the heart of the Mediterranean Sea, and made itself at home for weeks at a time.
    - detritus 3y ago
      My partner's from Marche, and boy do they have a bit too much water at the moment... :/

ggm 3y ago

Not a fan of geo-engeering when it's the "sulfur dioxide sunscreen" trick, or iron fertiliser in the sea. This one I'm sure has side effects, but seems marginally more plausible.

spuz 3y ago

This reminds me of the Salton Sea, a man-made lake in California which used to be promoted as a tourist destination and now continues to be an ecological disaster. https://en.wikipedia.org/wiki/Salton_Sea https://en.wikipedia.org/wiki/Salton_Sea

ZeroGravitas 3y ago
There is a similar "seaflooding" plan for that sea, and it is mentioned in passing at the end of the list of possible global sites in the article. https://www.latimes.com/california/story/2022-10-05/panel-rejects-idea-of-filling-salton-sea-with-ocean-water https://www.latimes.com/california/story/2022-10-05/panel-re...
- CommieBobDole 3y ago
  An issue with flooding the Salton Sea to sea level is you'd submerge a lot of agricultural land that already exists to the north and south of the Sea. Plus a number of towns (like Coachella) that already exist in the area. Though, if you could use this to maintain the water level and salinity at historical levels, you could avert the ecological disaster that's going to happen when the Salton Sea dries up. And it would likely become a popular area for recreation again, like it was in the 1950s and 60s.
  - bradleyjg 3y ago
    you'd submerge a lot of agricultural land that already exists to the north and south of the Sea Thus solving, or at least significantly migrating, the Colorado river over allocation problem. Win-win.
AbrahamParangi 3y ago
To be fair, it was accidentally created and so its water was intentionally cut off, causing the current ecological mess - which by the way also applies to other dried salt lakes too.
- 3y ago

thomasfromcdnjs 3y ago

I'd wager that "Seaflooding" will just happen somewhere anyway, likely some where we ain't really looking. And it will be fine. Mankind has seemingly surpassed weather patterns, and it now the 21st century.

x-complexity 3y ago

Any talks of flooding anywhere with water/sea just remind me of the "Flood Ohio" meme, both in terms of practicality & humour: https://www.youtube.com/watch?v=O4BPxKhRJRo https://www.youtube.com/watch?v=O4BPxKhRJRo

jeroenhd 3y ago

The idea of the Qattara sea is fascinating. On paper, it sounds so easy: dig a long trench and let nature run its course. There's so little life in the Sahara and there's so much Sahara around the theoretical sea that the ecological impact would be quite small for such a huge undertaking. With global temperatures continuing to rise and humanity preferring short-term profit over long-time survival, cooling even just a little bit of the Sahara could significantly extend the time people can live in northern Africa. I doubt we'll see the resurgence of the Green Sahara any time soon (the last period that kickstarted humanity in northern Africa was during an ice age, we're in the exact opposite situation of that) but even just a little bit of green and cool land in the desert could help a lot of people. Salinity would need to be kept in check, of course, but with a corridor big enough for tides to flow between the Mediterranean and the new sea there should be a quite manageable maximum salinity. Until that happens, we could harvest osmotic power ("blue energy") from the water stream, as fresher water will rush into the salt water reservoirs if we do not allow the minerals to flow back. Furthermore, with the new agricultural opportunities there need to be strict (and well-enforced) laws regarding pesticides and other types of contaminants to prevent another Lake Salton. With the current lack of agricultural possibilities in the area, this may actually be achievable if the government can see the long term benefits. It all sounds so incredibly doable. I don't think it'll ever happen because of politics and economics, and even if the project does get started I doubt it'll be long until the various terrorist groups active in northern Africa will find a new location to make the world a worse place, but I'm still very curious about what kind of world such projects could create.

pbmonster 3y ago
> Salinity would need to be kept in check, of course, but with a corridor big enough for tides to flow between the Mediterranean and the new sea there should be a quite manageable maximum salinity. First of all, this is not what the OP is suggesting. OP is using pipelines and wants to generate electricity from the potential energy. And for good reasons: between the suggested Qattara sea and the Med, there sits El Diffa square in the way. Which is 200m above sea level. You could tunnel that with a pipeline. Trenching that for a channel would be quite the project. Secondly, the Med only has a tidal range of 50cm. Using that to move a significant amount of water along a 100+km canal needs a truly humongous channel cross section. OP suggests using electricity to desalinate his sea. This would take insane amounts of energy, creating freshwater from desalination at the rate its evaporating across thousands of square kilometers in the Sahara takes orders of magnitude more power than the power station is going to generate. He also suggests using salt extraction pools. This only work, if rainfall creates fresh water rivers feeding his sea. Otherwise the water evaporating from this pool is lost to the sea, meaning you can only ever (at best) keep the salinity constant, but never decrease it. I think it's best to face it from the beginning: we're creating another Dead Sea. Salinity will prohibit life in the water and directly at the shore. Rainfall might make it possible away from the shoreline. But there will be absolutely no algae, shrimp or flamingos.

nickdothutton 3y ago

I’ve often wondered why we havent attempted something similar before. After all we have successfully drained the fens (in the 1600s, took only 7 years), constructed the hoover dam (1931, took 5 years), plus a dozen other significant geoengineering projects. There seems now to be a prevailing sentiment that geoengineering=bad among the general population.

aaron695 3y ago

[dead]

mkj 3y ago

If the climate-change induced sea level rise needs 1-2 metres of mitigation, and you have 100-200 metre deep depressions, you need to cover 1% of the Earth's surface (total, not just land) with these seafloods. Doesn't seem like a plausible mitigation, I'm puzzled why the article proposed it. The other benefits might be interesting locally some places.

jacobr1 3y ago
A few considerations: 1) you don't need to fully mitigate the sea-level rise for this to be of value. Even a few cm might make a difference on the margin for certain areas. 2) The projects themselves might be a value if we really could increase the productive value of currently arid parts of the land with net-positive environmental impact, so the sea-level rise doesn't matter or let's us do the project without worrying about sea-level drop. If we really had too-cheap-to-meter power for desalinization, then these projects might start to make sense, but it seems too soon to me.

culebron21 3y ago

The story seems so nice, but maths and observations on Quattara basin don't add up. First of all, climate around seas in deserted areas isn't much better than further in land. See the shores in Saudi Arabia, Dubai and Iran. But let's suppose someone decides to build the pipe and extract energy. It means one has to build a 58 km pipe under the ground (which is doable, like Gothard base tunner in Switzerland). Then, 4 issues remain: 1) you must treat the water coming in the pipes, because it's possible to clog the pipe, the turbine, etc. 2) what inclination do you need to get a reasonable discharge of water? 3) how much power one can extract from the flow? Rough estimates give me several megawatts per 10 m of elevation per 1 pipe of 10 m in diameter (this is the kind of size in new large-diameter tunnels). Seems like a lot of piping for not much power. 4) Erosion of the shores that may fill the basin up. This is what happens to natural lakes on plains. And key issue here: the more you discharge through the pipe, the higher the level of water in the lake, the less energy you can extract.

enedil 3y ago
Well, the air in Dubai is much more humid than in Riyadh (this is based on personal observation).
- culebron21 3y ago
  Does it feel better in Dubai than in Riyadh?
mnw21cam 3y ago
2) The Romans used an inclination of 1:1000. The Quattara basin is 80km from the Mediterranean and 60m lower. So it's not looking good straight away. As the water level rises, the drop will be even less. Also, the amount of water that can evaporate from such a large area is immense, so you'd have to have a rather huge channel for the water coming in just to keep up.
- zymhan 3y ago
  The romans were using gravity to move the water "for free". Using gravity to generate electricity is a different concept.

rtpg 3y ago

For a more nuanced view on the Egypt project in particular check the wiki page [0] Short version is it sounds uneconomical for power generation. Hard to believe but reading between the lines it feels like despite all the “free” hydroelectric you’re looking at immense construction difficulties You know your projects heading for the drawer when you propose using 100 atomic bombs to dig the tunnel [0] https://en.m.wikipedia.org/wiki/Qattara_Depression_Project https://en.m.wikipedia.org/wiki/Qattara_Depression_Project PS I’d love for this project to work. The main thing I could not really find supporting evidence for is “water will fill with life”. Just like… you could be constantly desalinating (and now have a brine problem) and still not really have a great ecosystem form I feel like? But I don’t understand this.

sampo 3y ago
That Wikipedia page talks about digging a 60 meters deep canal, not boring a tunnel.

FlyingSnake 3y ago

What are the 2nd and 3rd order effects that we're missing? Qattara depression lies in the Horse Latitudes that is full of arid deserts. So there's a high chance that flooding it might not make it turn into a lush wonderland. It could even end up being another dead sea. 1: https://oceanservice.noaa.gov/facts/horse-latitudes.html https://oceanservice.noaa.gov/facts/horse-latitudes.html

jjk166 3y ago

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

julienchastang 3y ago

Did anyone else notice the beautiful photography contained in this post? Unfortunately, after a quick scan, I could not find any attributions to the photos.

oh_sigh 3y ago
Some of them are stock photos from Getty. The map at the top is from one of sorgel's exhibitions for atlantropa, though I'm not sure if it his own design or something put together by another artist for the exhibition

deepsun 3y ago

> This would reduce global warming No, water albedo is lower than Sahara desert, so it would capture more of the Sun's energy, and warm the planet.

hok 3y ago

Drying the Mediterranean Sea is surely a bad idea, but I wonder why nobody ever built hydroelectric generators into the Strait of Gibraltar. There is a huge steady flow of surface water from the Atlantic into the Mediterranean (1 million cubic meters per second), and almost as much flows back into the Atlantic in deeper layers. Why not tap into these streams to generate electricity?

desas 3y ago
Tidal energy is expensive - sea water is very corrosive and under water maintenance access isn't cheaply solved. Also you need to retain access for ships and subs. The UK has the second highest tidal ranges in the world and is probably a world leader, we still generate nearly no energy from tidal.

senkora 3y ago

Out of curiosity, I checked what the air pressure would be in a drained Mediterranean, since the article claimed it would be oppressively high. The average depth of the Mediterranean is 1.5km [1] which is less than 2.0km which would be a pressure of 130.069kPa vs 101.312kPa at sea level [2]. This seems fine? [1]: https://en.m.wikipedia.org/wiki/Mediterranean_Sea https://en.m.wikipedia.org/wiki/Mediterranean_Sea [2]: https://www.physicsforums.com/threads/air-pressure-below-sea-level.640478/ https://www.physicsforums.com/threads/air-pressure-below-sea...

topaz0 3y ago
It wouldn't crush you or anything, but it would be notable. Just like the difference between sea level and 2km above sea level is quite notable.

ajuc 3y ago

The article complains that places under the sea level have higher pressure and are "hell on Earth" because of that. Dead sea coast(currently lowest on-land point on Earth) has a higher pressure because of that, and it's beneficial for human health, it's a health resort. The article seems to contradict itself (like the proposal to add water to salt so that we can evaporate the water and sell the salt :) ), and seems to be highly subjective and dishonest.

gmuslera 3y ago

People usually mentions sea rise as the worst outcome of global warming, but extreme weather may be more pervasive, and that may be experienced far earlier than the sea level rise. In any case, this is at best a mitigation, not a solution. It sounds like a simple enough idea, and may not have as a disruptive impact as other geoengineering proposals that may end having unexpected consequences. Some of the proposed flooded areas could have unique ecosystems that may be negatively impacted, but anyway all ecosystems are being negatively impacted right now, so a delay in the very bad trends we might be in could be positive overall.

yawpitch 3y ago

We are just about to force future generations to (quite likely not) live through the unintended consequences of current and past generations ignorantly and recklessly engineering their environment out of a misguided desire “[grow] the economy, and [make] money along the way”, and in response the author seems to suggest we use more ignorance and recklessness to drive even more unintended consequences? We don’t want to lose deserts and more than we wanted to lose forests and wetlands (and are now desperately trying to save them)… just because humans are too stupid to see the complex reasons why specific ecosystems exist doesn’t mean they should KEEP acting on that stupidity.