[HN Gopher] Seaflooding
       ___________________________________________________________________
        
       Seaflooding
        
       Author : deegles
       Score  : 294 points
       Date   : 2023-05-16 04:40 UTC (18 hours ago)
        
 (HTM) web link (unchartedterritories.tomaspueyo.com)
 (TXT) w3m dump (unchartedterritories.tomaspueyo.com)
        
       | Neil44 wrote:
       | 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 wrote:
         | The Age of Optimism declined due to observed results.
        
           | Neil44 wrote:
           | I don't think long term pessimism has amazing results either.
        
             | svnt wrote:
             | 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 wrote:
               | That the systems are equilibrium finding and that said
               | equilibrium will be 'amazing' are both quite bold
               | assumptions.
        
       | thomasfromcdnjs wrote:
       | 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.
        
       | ecology wrote:
       | 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
        
       | x-complexity wrote:
       | 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
        
       | petesergeant wrote:
       | 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.
        
         | rtpg wrote:
         | 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"
        
           | petesergeant wrote:
           | There are several factors, as I understand it, including
           | which way the wind normally blows, the Hadley cell, and the
           | location of mountains. All of these are applicable to the
           | Qattara basin project.
        
         | lproven wrote:
         | 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 wrote:
           | Persian Gulf gets up to 32-34C in summer. How hot exactly are
           | your proposed inland seas?
        
             | lproven wrote:
             | 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?
        
       | jjk166 wrote:
       | https://en.wikipedia.org/wiki/Salton_Sea
        
       | EdwardDiego wrote:
       | > 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 wrote:
         | 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 wrote:
           | 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?"
        
             | brutusborn wrote:
             | We _are_ being conservative. As the article mentions, these
             | kind of projects have been proposed and studied for half a
             | century now, and despite all the predicted benefits we
             | haven't event built a single one!
        
             | joshuanapoli wrote:
             | 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 wrote:
               | You're assuming linearity and arguing that all things are
               | equal. I would be surprised if either of those things are
               | true.
        
         | BurningFrog wrote:
         | The pervasive "Let's never do anything, just to be safe" mood
         | is what I dislike the most about this era. It is suffocating so
         | many possible paths to progress.
         | 
         | "You never know" is always true, Don't use it as a crutch.
         | 
         | Note: I'm an old man complaining about this era, not OP.
        
           | xpe wrote:
           | > The pervasive "Let's never do anything, just to be safe"
           | mood is what I dislike the most about this era. It is
           | suffocating so many possible paths to progress.
           | 
           | To evaluate such a claim with anything approaching
           | objectivity we would need a lot more detail.
           | 
           | What era are you speaking of? Why do you call it a 'mood'? A
           | mood of who exactly?
           | 
           | The way you phrase it is not an accurate characterization of
           | what people mean when it comes to concern about unintended
           | consequences. Your phrasing is a narrow, uncharitable
           | criticism.
           | 
           | You might be attempting to reference to a concept called the
           | precautionary principle?
           | 
           | > The precautionary principle (or precautionary approach) is
           | a broad epistemological, philosophical and legal approach to
           | innovations with potential for causing harm when extensive
           | scientific knowledge on the matter is lacking. It emphasizes
           | caution, pausing and review before leaping into new
           | innovations that may prove disastrous. - Wikipedia
           | 
           | Criticisms are well articulated on the Wikipedia page. They
           | are worth reading and discussing. They are fair and don't
           | rely on mischaracterizing what they criticize.
           | 
           | To be clear, I'm not taking a position here on the
           | precautionary principle. I am suggesting: don't be vague and
           | don't mischaracterize others' positions. Sorry if this sounds
           | harsh; it seems to me that people on Hacker News have the
           | intellectual horsepower and time to think and write well.
        
       | jeroenhd wrote:
       | 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 wrote:
         | > 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.
        
           | OsmMapper wrote:
           | The salt extraction pools can reduce the salinity to the
           | salinity level of the input water. The amount of effort
           | needed increases as you approach the salinity level of the
           | input so it isn't practical to achieve the exact same
           | salinity level as the input water. In this case the proposed
           | input water is from the Mediterranean which is not too salty
           | for life.
           | 
           | I'm not sure how much more salty the sea can be while still
           | having a reasonable ecosystem and an also not sure what ratio
           | of extraction pools to sea surface area would be needed to
           | achieve that so I don't know if it is actually practical.
        
           | marcosdumay wrote:
           | > OP suggests using electricity to desalinate his sea. This
           | would take insane amounts of energy
           | 
           | Well, making water fall 200m and desalinating sea water have
           | around the same change in entropy. If you have a very
           | efficient process, it will be close to break-even.
        
           | rob74 wrote:
           | > _Salinity will prohibit life in the water and directly at
           | the shore._
           | 
           | Maybe these guys might survive:
           | https://en.wikipedia.org/wiki/Brine_shrimp Also these:
           | https://en.wikipedia.org/wiki/Ephydra_hians - not really
           | impressive, but birds think they're yummy...
        
       | h4kor wrote:
       | 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
        
         | brutusborn wrote:
         | I doubt it, the Qattara Depression is a fraction of the size of
         | the Sahara. Marginally less fertile? Probably. Dead? No chance.
        
           | h4kor wrote:
           | As I understood it, the Sahara is not a stable system and can
           | relatively easily be greened again.
        
       | mkj wrote:
       | 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 wrote:
         | 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.
        
       | nickdothutton wrote:
       | 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.
        
       | culebron21 wrote:
       | 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 wrote:
         | Well, the air in Dubai is much more humid than in Riyadh (this
         | is based on personal observation).
        
         | mnw21cam wrote:
         | 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 wrote:
           | The romans were using gravity to move the water "for free".
           | Using gravity to generate electricity is a different concept.
        
       | euroderf wrote:
       | Dress up the Dead Sea project to attract tourism, and
       | Israeli/Jordanian co-operation will find a way.
        
       | rtpg wrote:
       | 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
       | 
       | 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 wrote:
         | That Wikipedia page talks about digging a 60 meters deep canal,
         | not boring a tunnel.
        
       | aaron695 wrote:
       | [dead]
        
       | gmuslera wrote:
       | 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.
        
       | ggm wrote:
       | 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.
        
       | NKosmatos wrote:
       | Very interesting article and the whole idea of controlled sea
       | flooding is well founded, but international geopolitics for sure
       | is a major obstacle.
        
         | lproven wrote:
         | 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.
        
       | senkora wrote:
       | 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 [2]:
       | https://www.physicsforums.com/threads/air-pressure-below-sea...
        
         | topaz0 wrote:
         | 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.
        
       | dvh wrote:
       | Or make Czech reservoir: https://prehrada.hrach.eu/en.html
        
         | FlyingSnake wrote:
         | I am sure the people living in Czechia will not like to live
         | underwater.
        
           | rhubinak wrote:
           | It will solve the housing crisis...
        
         | BurningFrog wrote:
         | I don't think inland seas will affect ocean levels?
        
       | FlyingSnake wrote:
       | 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
        
       | spuz wrote:
       | 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
        
         | ZeroGravitas wrote:
         | 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-re...
        
           | CommieBobDole wrote:
           | 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.
        
         | AbrahamParangi wrote:
         | 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.
        
           | mnw21cam wrote:
           | Also to be fair, it was created with water from a river that
           | had all sorts of horrible run-off from farms in it, which is
           | why it is so particularly toxic.
           | 
           | I'd expect projects like the ones mentioned in the article to
           | be slightly cleaner than that, but still pretty awful.
        
             | ajmurmann wrote:
             | I thought the run-off was just from surrounding farms and
             | continues till now. Is that not correct?
        
               | [deleted]
        
       | deepsun wrote:
       | > 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.
        
       | ajuc wrote:
       | 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.
        
       | aww_dang wrote:
       | 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-sh...
        
         | desas wrote:
         | Shipping to where exactly? How lucrative is the middle of the
         | Sahara desert market?
        
       | Gys wrote:
       | 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 wrote:
         | > 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 wrote:
           | 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 wrote:
           | 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.
        
             | keyle wrote:
             | Unlikely to be important, compared to the creation of
             | irrigation and additional plants and greenery that
             | generates O2 and absorbs CO2?
        
             | jonstewart wrote:
             | It all depends on clouds, though.
        
               | patall wrote:
               | It's always astonishing to me how pretty much every
               | climatologist will tell you "clounds are the joker". It
               | totally makes sense, but that doesn't make it in any way
               | less fascinating and is kind of funny.
        
             | throwaway290 wrote:
             | 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.
        
             | luxcem wrote:
             | Adding water to the atmosphere does not cause more warming
             | due to greenhouse effect at least not on this scale. Water
             | vapor concentration is regulated by condensation, adding
             | more water simply means more rain.
             | 
             | What is actually causing more warming is the increase of
             | temperature, that changes the equilibrium vapor pressure
             | point.
        
             | lproven wrote:
             | 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.
        
       | julienchastang wrote:
       | 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 wrote:
         | 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
        
       | alex_duf wrote:
       | 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.
        
         | Kortaggio wrote:
         | XKCD talked about why flooding Death Valley in this manner
         | would be a bad idea, because unless you remove all the salt and
         | sediments left behind from evaporation it would create a toxic
         | waste pool https://what-if.xkcd.com/152/
        
         | singularity2001 wrote:
         | I always find it disappointing to see how little evaporation
         | adds to the local greening (also see the boarders of Red Sea)
        
           | MichaelZuo wrote:
           | Well the Red Sea Coast has plenty of small plants, just no
           | forests, large grasslands, etc... due to local climate.
           | 
           | It's probably unlikely for a verdant grassland to pop up next
           | to the Qatta depression, but a lot of small plants I can
           | believe.
        
           | mike-the-mikado wrote:
           | It is claimed that a lack of trees leads to a lack of rain
           | (leading to a lack of trees)
           | 
           | https://www.theguardian.com/environment/2021/mar/20/our-
           | bigg...
        
           | lasfter wrote:
           | [1] argues a crucial component of greening is trees "pumping"
           | water from the oceans inland and creating nutritious soil.
           | Otherwise evaporated water is simply blown away by the wind.
           | I'm sure other local terrain (e.g., mountains) play a part in
           | locally retaining evaporated water and creating conditions
           | for rain.
           | 
           | [1] The Hidden Life of Trees: What They Feel, How They
           | Communicate--Discoveries from A Secret World by Peter
           | Wohlleben.
        
         | BurningFrog wrote:
         | 70% of the planet is filled with salted water, which are
         | thriving ecosystems.
         | 
         | Is there any reason I'm missing why expanding the ocean won't
         | just give us more ocean?
        
           | bradleyjg wrote:
           | I think most of the oceans are a barren wasteland.
           | 
           | That said, as a shallow and, at least at first, nutrient rich
           | part of the ocean it could be a flourishing part of it. But
           | if it's filled via underground pipe, it'll be isolated from
           | sources of ocean life.
        
             | zaphar wrote:
             | I think most of the oceans are a barren wasteland.
             | 
             | This is as far as I know, incorrect. I'm not sure why you
             | think it would be true. Oceans, aside from areas like the
             | Dead Sea are some of the most vibrant and life filled
             | ecosystems we have. Even at the most crushing depths far
             | from the sun there are entire ecosystems on the ocean
             | floor.
        
               | black_puppydog wrote:
               | But as you say: except for the dead sea.
               | 
               | In my mind, these new seas would have a steady influx of
               | salt water, but only sweet water would evaporate out of
               | them. And since I don't see the mechanism by which salt
               | would get sequestered or removed from these bassins, I'd
               | also guest their salt concentration would rise quite
               | quickly.
               | 
               | Of course, it might still be interesting to have a huge
               | water surface in the area that effectively serves as a
               | rain generator, but it might not be the same thriving
               | ecosystem we imagine when we say "ocean".
        
               | akiselev wrote:
               | The GP is technically correct. By volume much of the
               | ocean is practically a wasteland because of the oxygen
               | minimum zone [1]. A few animals like vampire squid are
               | adapted to this zone but for the most part, the vast
               | majority of ocean life is found in the top and bottom
               | most layers.
               | 
               | [1] https://en.wikipedia.org/wiki/Oxygen_minimum_zone
        
               | bradleyjg wrote:
               | From articles like this one:
               | https://edu.rsc.org/feature/iron-ocean-
               | seeding/2020176.artic...
               | 
               | Could be wrong.
        
               | BurningFrog wrote:
               | The Dead Sea is a lake, which is why it's dead.
        
           | cryptonector wrote:
           | Filling basins with ocean water will not increase the volume
           | of sea water. It will probably increase the area of sea water
           | (thus increasing evaporation, causing more precipitation, and
           | speeding up the water cycle, which has a net cooling effect
           | on the planet), and it will lower sea levels. Win win win
           | win!
        
             | mecsred wrote:
             | You're underestimating just how big the oceans are.
        
           | coryfklein wrote:
           | Depends on whether the rate of salt extraction is precisely
           | equal to the inflow over the long term. The Great Salt Lake
           | is extremely salty and basically only two species can live in
           | it: brine shrimp and brine flies. With about the
           | corresponding level of "tourism" you'd expect.
           | 
           | And that is with industrial levels of salt harvesting. Would
           | we expect the salt harvesting of these inland seas to be
           | equal to or greater than the daily inflow of salt via the sea
           | water? Seems dubious to me.
           | 
           | On the other hand, there are still many other benefits.
           | Migratory birds love the Great Salt Lake. The Great Salt Lake
           | Effect[0] on precipitation in this desert seems unambiguously
           | positive.
           | 
           | [0] https://en.wikipedia.org/wiki/Great_Salt_Lake_effect
        
             | ignite wrote:
             | > there are still many other benefits.
             | 
             | Too bad it's going away.
             | 
             | https://www.theguardian.com/environment/2023/jan/10/utah-
             | gre...
        
             | BurningFrog wrote:
             | If you make it a bay of the Mediterranean, it should behave
             | no differently than the rest of that ocean.
             | 
             | With the various pipeline/tunnel/channel options that are
             | admittedly more realistic, at least at first, there might
             | very well be the kind of problems you mention.
        
             | Gordonjcp wrote:
             | > Migratory birds love the Great Salt Lake
             | 
             | some birds, flying:
             | 
             | "hey you want to come and eat some shrimp?"
             | 
             | "yeah I could go for some shrimp, know anywhere good?"
             | 
             | "well yes actually, but it's a bit of a trek"
             | 
             | "okay cool, sky trip!"
        
           | alex_duf wrote:
           | That's a fair point, I only had a land ecosystem in mind when
           | writing it, sure there would probably be plenty of sea life
           | in there.
        
         | moffkalast wrote:
         | Well given that a fair bit of the Netherlands was made this
         | way, I would think it's not impossible to make it usable land.
        
           | a2800276 wrote:
           | Pretty sure that none of the Netherlands were created by
           | flooding large depressions in a desert. Quiet the opposite,
           | in fact.
        
           | lambdasquirrel wrote:
           | The Netherlands does not sit in a dry arid area though. When
           | they reclaimed / drained it, it became like the areas near
           | it.
        
         | throwaway290 wrote:
         | > 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/2017/1
         | 1/09/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?
        
           | alex_duf wrote:
           | >Which should benefit from this the most.
           | 
           | But that's making an assumption about their desire, maybe
           | they don't love the idea of being displaced and having to
           | have another activity (tourism or whatever) in order to live.
           | 
           | Regarding the organisms living there, my point is we don't
           | know what effect getting rid of such an ecosystem could have
           | in the global scale. Maybe whatever bacteria / insect / small
           | mammal that manages to survive there is useful for a species
           | of bird that stops there on their way to another reproduction
           | site. We can look at it and think by filling it with water it
           | will be "better", whatever better means, but there are
           | serious unknown unknowns that we can't take into account.
        
             | DrScientist wrote:
             | Exactly - history is littered with unintended consequences.
        
               | throwaway290 wrote:
               | The ship for "maybe we should not do something lest we
               | disrupt the ecosystem with unintended consequences" has
               | sailed.
        
               | Peritract wrote:
               | The solution to negative unintended consequences is not
               | to trigger more and hope that the next lot are positive.
        
               | throwaway290 wrote:
               | Maybe a solution to unintended negative consequences from
               | destructive activities that never cared about
               | environmental impact until too late is more so a
               | constructive project with intended positive consequences
               | and specific environmental goals and less so the default
               | alternative of "keep doing those destructive projects as
               | before and stall anything else"
        
             | throwaway290 wrote:
             | > there are serious unknown unknowns that we can't take
             | into account.
             | 
             | We can model stuff. Also we don't find out if we don't try.
             | 
             | I just don't get how we are fine with causing constant
             | large-scale intentional harm to environment for industrial
             | purposes even as there were so many unintended
             | consequences, but when considering a major project
             | _specifically_ aimed to benefit our environment and long-
             | term humanity it 's instantly the apathetic "oh but what
             | if?".
             | 
             | Plus consider the amount of free clean water energy and
             | positive uses of that as a result of this project.
        
               | akiselev wrote:
               | Because even industrial pollution at a modern scale is
               | small potatoes compared to the possible consequences of
               | honest-to-god intentional _geoengineering._ The risks
               | here are in a completely different league.
               | 
               | We recently found out that the Amazon rain forest depends
               | on winds that carry nutrients from the Bodele depression
               | [1]. The Amazon rainforest is nutrient limited by the
               | phosphorus it gets _from the other side of the planet_.
               | Obviously the depression is way above sea level and isn't
               | at risk from artificial flooding in the northern sahara,
               | but that should illustrate the scale of the consequences
               | we're dealing with: if we fuck up even a little bit, it
               | could mean ecosystem collapse in the Mediterranean or
               | beyond.
               | 
               | [1] https://earthobservatory.nasa.gov/images/7279/bodele-
               | depress...
        
               | throwaway173738 wrote:
               | People constantly overestimate the benefits and
               | underestimate the harms on projects like this. Where I
               | live we made it a point to dam up a lot of rivers to get
               | hydroelectric power, but the dams prevented fish in the
               | area from returning home to spawn, weakening our
               | fisheries. And in the end the dams don't produce that
               | much power.
        
               | throwaway290 wrote:
               | All projects like that are done for money or energy first
               | though. We know they all come with possible environmental
               | damage and all they do is try to mitigate it. These
               | projects keep being done and we don't bat an eye.
               | 
               | This is different in that it has environmental
               | improvements as goals. Lower sea levels a bit, enrich
               | local ecosystem, etc. So it's a bit sad that when it
               | comes to projects like there is always paralysis but not
               | when we just want more stuff.
        
               | burnished wrote:
               | Part of it is just the audience. Your average HN comment
               | section would likely fiercely debate the creation of
               | crosswalks, curb cuts and other common sense improvements
               | (though that may be true of the population at large).
               | 
               | If the things you felt like dont receive enough attention
               | were available for this level of public scrutiny well, I
               | think you can rest assured it would receive it.
        
         | konschubert wrote:
         | > 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.
        
         | coryfklein wrote:
         | Agreed.
         | 
         | The biggest point that seemed missing to me: the author talked
         | so much about increased evaporation, but isn't water vapor one
         | of the worst greenhouse gases? Sure you mitigate sea level
         | rise, but at the cost of increasing temperatures? That doesn't
         | seem like a great tradeoff.
        
           | bonzini wrote:
           | The water just moves, doesn't it? He's saying to build a
           | canal.
        
             | coryfklein wrote:
             | I guess it depends on whether such canals increase the net
             | surface area. If you raise the ocean by 3mm across the
             | globe, does it result in the same net increase in surface
             | area as flooding a large swath of the Sahara?
        
           | snewman wrote:
           | You are correct that water vapor is the primary greenhouse
           | gas. Despite that, water vapor emissions are not generally
           | considered to impact warming. I think that is because the
           | water content of the atmosphere is already in balance due to
           | the massive amount of evaporation and condensation (e.g.
           | rain) that is constantly going on. If we dump some extra
           | water vapor into the atmosphere, that will balance out as a
           | bit of extra rain and/or a bit less evaporation somewhere
           | else; atmospheric water vapor levels won't change.
           | 
           | I don't know whether a large scale, ongoing intervention,
           | such as permanently flooding a large area, could nudge this
           | balance sufficiently to result in a sustained (if small)
           | increase in atmospheric water vapor content, and thus an
           | increase in warming. An interesting question!
           | 
           | I wrote about the role of water vapor in global temperatures
           | a while back at
           | https://climateer.substack.com/i/60052576/you-thought-the-
           | ma.... My primary source was an IPCC report, specifically the
           | sidebar on pages 8 and 9 of this PDF: https://www.ipcc.ch/sit
           | e/assets/uploads/2018/02/WG1AR5_Chapt....
        
         | goda90 wrote:
         | I think tidal canals would be the better option than pipelines.
         | Dig channels deep and wide enough that the water of the seas
         | actually mingle, letting dissolved salts spread out into the
         | wider ocean.
        
           | ajmurmann wrote:
           | With quite a bit of extra digging this could get us an
           | alternative to the Suez Canal which I believe many countries
           | would be interested in and would strengthen global trade.
        
             | vasco wrote:
             | They already added lanes to the suez canal and I imagine
             | it'd be way more cost effective to keep expanding those as
             | needed.
        
           | bell-cot wrote:
           | For that "deep and wide enough" to work out, just how deep
           | and wide would the canal need to be?
           | 
           | Such mingling happens at the Dardanelles - but it's half a
           | mile or so wide, and ~180 feet deep.
           | 
           | https://en.wikipedia.org/wiki/Dardanelles
        
         | cryptonector wrote:
         | Presumably all these could be allowed to get saltier than the
         | seas they fill from. That would allow more water to evaporate,
         | which would speed up the water cycle, which has a net cooling
         | effect on the planet, and which would cause more precipitation
         | that would then help green the planet. It would also tend to
         | lower sea levels. Win win win win!
        
       | detritus wrote:
       | 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 wrote:
         | > 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.
        
         | kwhitefoot wrote:
         | Sounds a bit like the Desertec project.
        
         | marcosdumay wrote:
         | > a little cooler
         | 
         | Hum... About this little bit, increasing low altitude humidity
         | is almost guaranteed to make the place hotter, not cooler. Even
         | if it adds vegetation.
        
       | villgax wrote:
       | 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.
        
       | hok wrote:
       | 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 wrote:
         | 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.
        
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