Researchers Propose New Structures To Harvest Untapped Source of Freshwater (illinois.edu) 85
An announcement from the University of Illinois Urbana-Champaign:
An almost limitless supply of fresh water exists in the form of water vapor above Earth's oceans, yet remains untapped, researchers said. A new study from the University of Illinois Urbana-Champaign is the first to suggest an investment in new infrastructure capable of harvesting oceanic water vapor as a solution to limited supplies of fresh water in various locations around the world.
The study, led by civil and environmental engineering professor and Prairie Research Institute executive director Praveen Kumar, evaluated 14 water-stressed locations across the globe for the feasibility of a hypothetical structure capable of capturing water vapor from above the ocean and condensing it into fresh water — and do so in a manner that will remain feasible in the face of continued climate change. Kumar, graduate student Afeefa Rahman and atmospheric sciences professor Francina Dominguez published their findings in the journal Nature Scientific Reports....
"Eventually, we will need to find a way to increase the supply of fresh water as conservation and recycled water from existing sources, albeit essential, will not be sufficient to meet human needs. We think our newly proposed method can do that at large scales," Kumar said.
The researchers performed atmospheric and economic analyses of the placement of hypothetical offshore structures 210 meters in width and 100 meters in height. Through their analyses, the researchers concluded that capturing moisture over ocean surfaces is feasible for many water-stressed regions worldwide. The estimated water yield of the proposed structures could provide fresh water for large population centers in the subtropics....
"The climate projections show that the oceanic vapor flux will only increase over time, providing even more fresh water supply," graduate student Afeefa Rahman said. "So, the idea we are proposing will be feasible under climate change. This provides a much needed and effective approach for adaptation to climate change, particularly to vulnerable populations living in arid and semi-arid regions of the world." The researchers said one of the more elegant features of this proposed solution is that it works like the natural water cycle. "The difference is that we can guide where the evaporated water from the ocean goes," Dominguez said....
The researchers said this study opens the door for novel infrastructure investments that can effectively address the increasing global scarcity of fresh water.
Thanks to Slashdot reader L.Kynes for submitting the news.
The study, led by civil and environmental engineering professor and Prairie Research Institute executive director Praveen Kumar, evaluated 14 water-stressed locations across the globe for the feasibility of a hypothetical structure capable of capturing water vapor from above the ocean and condensing it into fresh water — and do so in a manner that will remain feasible in the face of continued climate change. Kumar, graduate student Afeefa Rahman and atmospheric sciences professor Francina Dominguez published their findings in the journal Nature Scientific Reports....
"Eventually, we will need to find a way to increase the supply of fresh water as conservation and recycled water from existing sources, albeit essential, will not be sufficient to meet human needs. We think our newly proposed method can do that at large scales," Kumar said.
The researchers performed atmospheric and economic analyses of the placement of hypothetical offshore structures 210 meters in width and 100 meters in height. Through their analyses, the researchers concluded that capturing moisture over ocean surfaces is feasible for many water-stressed regions worldwide. The estimated water yield of the proposed structures could provide fresh water for large population centers in the subtropics....
"The climate projections show that the oceanic vapor flux will only increase over time, providing even more fresh water supply," graduate student Afeefa Rahman said. "So, the idea we are proposing will be feasible under climate change. This provides a much needed and effective approach for adaptation to climate change, particularly to vulnerable populations living in arid and semi-arid regions of the world." The researchers said one of the more elegant features of this proposed solution is that it works like the natural water cycle. "The difference is that we can guide where the evaporated water from the ocean goes," Dominguez said....
The researchers said this study opens the door for novel infrastructure investments that can effectively address the increasing global scarcity of fresh water.
Thanks to Slashdot reader L.Kynes for submitting the news.
Condensing in hot climates (Score:2)
Re:Condensing in hot climates (Score:5, Funny)
The Skywalker family figured how to do it on Tatooine
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Re:Condensing in hot climates (Score:4, Interesting)
Why can't they just bring up cold water from deep depth (below 1000ft) and condense it on the spot? Use floating wind turbines to power everything. Store the fresh water in underwater bladders, then send a ship out to bring the water back. If that works, then build more permanent pipes.
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Partly because it's expensive and partly because you have to get rid of the waste, highly saline, water with all the environmental damage that this causes.
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What is the expense of a lack of freshwater to sustain the population?
There is an expense in everything we do. There is an expense in calories to rise from bed and turn on the light. This is returned in abundance from going to work and providing food, clean water, shelter, and perhaps a few luxuries. If not then we'd all lie in bed until the inevitable comes.
From desalination comes highly saline water. Without that freshwater comes the thirst of many human lives, and likely the starvation of those same
The real question is farming (Score:2)
In California, household water usage is insignificant for addressing the drought. Only 5% of water is used by households. In contrast, 40% is used by farmers, and that problem is aggravated by old laws on water rights that are mind-boggling and encourage waste. Until California is willing to address the elephant in the room (i.e., the illogical water rights laws), no other actions matter.
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Your argument is, as far as I can tell, that this is important and vital so we should do it regardless of the environmental and economic cost.
That seems backward. If it is important and vital, we should put lots of effort into doing it as cheaply and cleanly as possible.
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No, the water vapor is essentially salt free; it can't evaporate or "dissolve" in the vapor phase. You can get some salt buildup from ocean water that splashes onto something and then is allowed to evaporate. It's a very punishing environment.
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Partly because it's expensive and partly because you have to get rid of the waste, highly saline, water with all the environmental damage that this causes.
You're raising a fake issue. After desalination separates salt and water, the water passes through a city and after sewage treatment re-enters the ocean again. There is no net build-up of salt in the sea.
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Okay. Well, the linked article notes that it is a problem. Clearly, we are not talking about salt building up in the sea over the whole sea. We are talking about localized damage to wild life in the area of the discharge and for a significant area downstream.
Of course, you might say "who cares about fish", but if the local population eat the fish then you probably do. Or if the you are killing of kelp forest or mangrove swamp that it stabilizing the local shoreline and preventing erosion, you probably do.
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Okay. Well, the linked article notes that it is a problem. Clearly, we are not talking about salt building up in the sea over the whole sea. We are talking about localized damage to wild life in the area of the discharge and for a significant area downstream.
Of course, you might say "who cares about fish", but if the local population eat the fish then you probably do. Or if the you are killing of kelp forest or mangrove swamp that it stabilizing the local shoreline and preventing erosion, you probably do.
Of course we want to spread the stuff out when we return brine to the sea, to avoid those local effects.We also have the option of retaining salt on land, for its numerous industrial uses. But why do Greens have to miscast every trivial engineering problem as a showstopper as their universal excuse for clubbing to a halt every engineering solution to the environmental problems they raise? Can't generate baseload clean energy, can't desalinate away the drought crisis, can't build anything...
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Slashdot covered this a while ago [slashdot.org].
Re:Condensing in hot climates (Score:5, Interesting)
Well it's not equally hot all the time; there's this big hot thing in the sky called "the Sun" that conveniently goes away every night. You can then easily capture moisture for the cool, super-saturated morning air.
Years ago I took a jeep drive through Chile's Pan de Azucar national park, in the norther reaches of the Atacama desert. That's the driest desert on Earth; when I was visiting it hadn't rained in five years. Rather than truck water into the remote ranger stations, they set up mist nets called "atrapanieblas [wikimedia.org]" on high bluffs over the ocean to harvest moisture from morning mist coming off the sea.
The real problem with scaling this from a solution that will keep a single park ranger alive to something that will keep millions of people alive, is that your mist net system would need to be millions of times larger. Alternatively you could put the system actually on the ocean to take advantage of greater concentration of moisture, but oceans are where they are for a reason: they're in low places. People live on dry land, which is usually higher. Real water distribution systems exploit the fact that water flows downhill. They may have pumps in places to build up local water pressure or to get the water over obstacles, but pumping is expensive.
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Heres a better idea (Score:2)
Stop collecting storm water and waste water in concrete canals and then fast tracking it into the ocean where its i useable. Instead return it to the ground in a manner that makes it useable for drinking irrigation etc.
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Lack of water isn't the problem (Score:2, Interesting)
Too many people is the problem. We pollute streams and rivers left and right which prevents use of said water. During covid, I came across two pictures of the exact same stream somewhere in India. The first picture showed what it normally looked like: mountains of suds from the various businesses which lined the stream. The second picture, taken from the same spot, showed not a single bubble anywhere as the businesses were shut down during the pandemic.
More recently, this story [slashdot.org] was posted about the amount
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You first. You know what to do with yourself.
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You first. You know what to do with yourself.
Every time this is brought up, this is the response, because clearly there is no other way to reduce the world's population than by an immediate extermination. I'm presuming it's never occurred to people that not having kids might be a better, more sustainable method.
People may have criticized China's one child policy, but it was the correct one. It was only its implementation which failed since there were vast numbers of female kids killed because everyone there wants a male child.
If there was a worldwide
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You first. You know what to do with yourself.
Every time this is brought up, this is the response, because clearly there is no other way to reduce the world's population than by an immediate extermination.
Because the subtext of this statement starts getting rather unnerving relatively quickly. I'll get to the One Child Policy in a moment, but even if it were successful, it'd take several decades (if not more) for the contraction to achieve the proposed goal. "We need to reduce the number of new people being born worldwide in order to ensure the global population eventually achieves a sustainable level" would sound way better than "population reduction". The problem is that the latter statement can indeed inc
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A one child policy, no matter the implementation, was always doomed to fail. We've known for a very long time that to maintain a human population there needs to be somewhere between 2.2 and 2.5 children per mother. This is because of factors like early child death, cases of infertility, and so many other factors of life that prevent the child from pairing up to produce more children as an adult. Even if the culture of China had not favored male children it would have still resulted in a population collap
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Again moderation on Slashdot is devolving into "agree/disagree" than a condition of being insightful, interesting, or informative. Moderating me down for pointing out the failure if China's one child policy is fine. It doesn't change the outcome. China is on the path of failure. They will have to embrace capitalism or end up an isolated island of poverty and misery like North Korea.
Removing the ability of parents to assure their genetic line would progress by having 2.5 children (or perhaps 2.2 children
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Who knew America's one child policy would be so sucessful?
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People are having fewer kids. The world population is projected to peak some time by or before 2100 and drop after that. The timing depends a bit on how fast quality of life and human rights improve in the least developed areas, but not as much
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So, the Thanos solution?
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You hear this, people of the world? Stop fucking. There, I've announced it for you. Our problem can now be considered solved.
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You hear this, people of the world? Stop fucking. There, I've announced it for you. Our problem can now be considered solved.
Fuck all you want. Just don't have kids. Birth control, condoms, abortions, or abstinence. All produce the same resuls. Fewer kids.
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Mostly it's because in places like Somalia, there's little else for men and women to do for entertainment, and women have almost no access to fertility management or birth control tools. Where there is a high level of infant mortality due to disease etc there's also more compulsion to have more kids so some survive to adulthood.
In the west, it's now a reasonable assumption that if you have two kids, it's likely they will grow to adulthood. In Sierra Leone, with one of the highest rates of infant mortality i
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Religion and culture are a significant portion of the blame for this problem.
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Reduce the population by at least 1/4
I thought that you are crazy. But it turns out that there is something in what you are saying. How many people can Earth actually support?
This however considers the current desired standards of living. For example without replacing animal-based food with plant-based replacement.
Until cultures change radically, the optimum number of people to exist on the planet at any one time lies in the vicinity of 1.5 billion to 2 billion people.
Optimum human population a third of present, scientists say - Stanford News
These data alone suggest the Earth can support at most one-fifth of the present population, 1.5 billion people, at an American standard of living.
https://www.britannica.com/exp... [britannica.com]
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The earth is perfectly capable of supporting orders of magnitude more humans than there currently are. We're just currently very bad at mechanisms for effective resource allocation (even the best methods we have and use are still terribly poor) so we have great disparity in living conditions, resource utilization efficiency etc.
Necessity is the mother of invention. We're at the most populous moment in human history, but also the most efficient, the overall wealthiest, safest, healthiest... and as the popula
Prove it (Score:1)
Sounds interesting on paper but I'm waiting for a proof of concept installation.
Why not just desalinate (Score:4, Insightful)
Rather than literally chasing clouds, why not build nuclear power plants and de-salination plants all around the coast of every country?
Then you could pipe unlimited fresh water anywhere in the country you liked. Everyone could have lawns made up of nothing but exotic orchids that would have misters going 24x7, even in the desert...
It's crazy that we live in a world all this technology is simple and well understood, we have a planet that is mostly water, yet this has not been done already (well OK maybe not the orchid part).
We should start building this now before multiple giant cities are forced to do something like it at greater expensive when aquifers are completely drained.
Re:Why not just desalinate (Score:4)
The energy balance is pretty important with whatever solutions you leverage, and without a kWh/m3 number for their proposed solution it is hard to know if it is comparable or "better" than direct desalination. You also have the issue of salt/brine disposal-- you could be looking at up to 10-20,000 m3 of waste salt per day.
But personally I tend to think that desalination is a great match with nuclear, especially if you are looking at a molten salt coolant or other high-temperature process where your levels of waste heat can still be used for process applications.
Re:Why not just desalinate (Score:4, Insightful)
You also have the issue of salt/brine disposal-- you could be looking at up to 10-20,000 m3 of waste salt per day.
This is not that big of a deal as people let on. The issue is you can't dump it back into the ocean conveniently, like close to shore. You have to pump the brine back out past the local ecosystem and dump it in deep water. We are talking a 100 miles or more offshore. You probably want to use a permeable pipe at some point so not to dump all the brine at one point. Spread it out so not to raise the salinity of one area to much.
Exactly (Score:1)
especially if you are looking at a molten salt coolant or other high-temperature process where your levels of waste heat can still be used for process applications.
People often ignore this but raw heat is extremely valuable for a lot of industrial processes, so anything that generates a lot of excessive heat can be used to help industry where you don't have emissions created to generate that heat.
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Rather than literally chasing clouds, why not build nuclear power plants and de-salination plants all around the coast of every country?
You don't even need nuclear for this. There are a number of solar de-salination plants that work just fine too. There are so many ways to get fresh water, the fact that we haven't done it yet is plainly ridiculous.
In some places where drought is practically stereotype there is plenty of fresh water. Africa for example. A study found there is plenty of deep water aquafers that could provide for the needs of Africa for over a hundred years. There is just no will to tap those.
Re: Why not just desalinate (Score:2)
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Yeah, we should use those resources today, because the people need them today. There are times when you have to use what you have and not worry about the future. a hundred years is a long time to come up with a better plan.
Just to note, I'm actually not sure if they said 100 years or 1000 years in the documentary. I went with the lower number.
Re: Why not just desalinate (Score:2)
Not looking long-term is how we got into this mess.
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Libya is tapping that water as we speak. It's just a question of money. Places that are poor to start with tend not to have the money for big infrastructure projects.
Getting it out of the ground, or using solar, are the best options. Nuclear in Africa is a non starter. Way too expensive, takes way too long to build, and there is no infrastructure for it - no fuel supply or waste disposal, no regulators, no supply of highly skilled nuclear scientists, no domestic designs...
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Getting it out of the ground, or using solar, are the best options. Nuclear in Africa is a non starter. Way too expensive, takes way too long to build, and there is no infrastructure for it - no fuel supply or waste disposal, no regulators, no supply of highly skilled nuclear scientists, no domestic designs...
I'm going to do something rare and concede that you have a good point. Africa is far to politically unstable to build nuclear power plants in. Most of the other issues you addressed could be overcome with the right aid but political instability is a show stopper as far as nuclear power is concerned.
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The problem with desalination is brine. By desalinating sea water, You make two things; fresh water, and extra salty water, which, if simply dumped directly back into the ocean, creates local dead spots, as the area becomes to salty to support sea life. Dealing with brine disposal is a major hurdle to mass desalination.
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Re: Why not just desalinate (Score:2)
Compared to the number of dead spots caused by the pollution from dead rivers I'd say brine is a virtual irrelevance.
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The problem with desalination is brine
Brine isn't that big of a deal once some thought it put into it.
Brine is nothing really salty water. Remove the rest of the water and you have a resource, salt. Lots of use for salt.
If you choose to dump it, you don't just dump it all back in the sea in one spot. There are plenty of "dead" spots in the deep ocean. You can pipe the brine into the deep ocean but instead of one spot, you use a permeable membrane and spread the brine out and defuse it.
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This is solar desalination. If it's practical, it's the best kind because the solar collectors and evaporators are already made, you just have to build the condensers. And it doesn't require burning what, in your free water for everybody scenario, would be a surprisingly limited supply of fissile fuel.
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We could build all those nuclear plants and they could be perfectly safe. But history suggests that cost concerns will override long or short-term safety concerns.
Wrong (Score:1)
But history suggests that cost concerns will override long or short-term safety concerns.
I was just listing to a summary of nuclear power industries around the wold. Currently in Europe proposals for SMRs cost HALF of either natural gas power, or new proposed renewable projects like wind and solar. (this was in Estonia but applies generally to all countries in the EU, it's a Swedish power company funding an SMR in Estonia).
That;'s because the price of everything is going up used to make renewables, and fo
Paging Dr Ian Malcolm (Score:2)
It will never work (Score:4, Interesting)
I am always amazed when a university makes claims of a new and wonderful plan to save the world without checking without physics depart first. This is one of many examples where "Researchers" claim to be able to condense water from air in presumed industrial scale. Sure, you can get it work work but the math is not on your side. According to this webpage [engineeringtoolbox.com] you have extract over 670 watt-hours of energy in the form of heat to condense one kg of water at 25 deg C. Our best technology needs about 1/3 as much energy to make that transfer happen, power to move of the that amount of power to transfer allows us to move that much energy or roughly 225 watt-hours.
Re:It will never work (Score:4, Interesting)
If you are in deep enough water you likely can "free cool" the vapor with a cooling loop going down a few hundred meters. There are also isothermal dehumidification (and near-isothermal) techniques that could be used with greater thermodynamic efficiency. Unfortunately the summary lacks information on the proposed energy consumption so it is pretty hard to evaluate.
Energy requirements? (Score:2)
Meh. It’s a science article, not an engineering analysis. Cool idea though. Mechanically very simple. C
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I think this is really the important part of the equation. Significantly less chemicals required to treat saltwater, less wear, all kinds of similar benefits. Still need the energy use though for it to be meaningful.
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Vacuum distillation has very few consumables too, it's not just competing with RO.
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Isn't [multi-effect] vacuum distillation still more energy intensive (even assuming free waste heat) than RO?
It's not un-tapped (Score:4, Interesting)
It creates rain when it comes onshore. It also makes fog. If you had enough water suckers off shore in California, less fog, bye-bye redwoods. One of these projects isn't going to affect global climate, but I bet we could make a pretty big show of screwing over some local climate and then it's lawsuit time if they can actually show reduced humidity and/or rainfall over some critical agricultural zone.
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I'm glad that I'm not the only person who sees this as a potential downside. I'd like to see what the environmental impact is projected to be.
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I live in the coast ranges, and soil subsiding in smaller valleys is a thing here too. The worst part is that once that starts happening, it means the underground reserves are compacting and won't recharge as much as they did before they were over-subscribed. Of course they're still approving new vineyards and now pot farms, because money.
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I was wondering what will happen if you start to suck out moisture near the ocean fronts or even in the middle of the ocean.
Looks like I was not the only one thinking about that.
A simple version already exists (Score:5, Informative)
Vapour catchers in Chile - and no doubt elsewhere by now
https://www.newscientist.com/a... [newscientist.com]
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totally worked on Arrakis as well.
Anything but... (Score:2)
Mmmmm... microplastics! (Score:2)
I'd tap that (Score:2)
Untapped does not mean unused: that water is already part of multiple interacting ecosystems.
Careful, there, please.
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Untapped does not mean unused: that water is already part of multiple interacting ecosystems.
Careful, there, please.
Exactly. Taking resources from the environment can have amazingly unpredictable repercussions. Wind power, thats ok isn't it? Long term? Taking energy out of the wind? Where else would that energy be used? Shaking trees, moving clouds, blowing dust around... and your just going to remove that energy and nothing in nature is going to change?
But then again, nature itself is not stable. I remember hearing David Attenborough talking about how humans are disrupting the stability of nature. I can't help but think
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... nature IS NOT stable.
Hmm. True as far as it goes, but on a human (time) scale I'm not sure we're capable of sufficient discernment.
I think I'd rephrase this as nature has multiple meta-stable states. Push or pull too hard and it changes from its current state into another and, without another intervention, it will not switch back (in an appreciable timeframe) of its own accord.
We haven't even begun to map all of these states yet, but it's safe to say we don't want to fall into some of them.
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... nature IS NOT stable.
Hmm. True as far as it goes, but on a human (time) scale I'm not sure we're capable of sufficient discernment.
I think I'd rephrase this as nature has multiple meta-stable states. Push or pull too hard and it changes from its current state into another and, without another intervention, it will not switch back (in an appreciable timeframe) of its own accord.
We haven't even begun to map all of these states yet, but it's safe to say we don't want to fall into some of them.
That is so true. Snowball Earth would not be a nice place to live, not even if you really really like alpine sports.
It's the distribution, stupid (Score:2)
Just like food, the problem isn't supply but distribution. This concept may help people who live near the ocean or other large bodies of water, but what about the inland areas? Transporting enough water to support a large population is a problem with no apparent solutions. Pipelines would be extremely expensive and ultimately inadequate (pumping energy costs alone would be infeasible). You can't pump water over a mountain range. Tanker trucks? Again, it wouldn't scale.
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I read an article (sorry, I don't have a link) that analyzed the amount of electricity it would take to power the pumps to move water from the Great Lakes to the western US, over a couple of major mountain ranges. It was enormous, more than the total capacity of our current (no pun intended) grid.
do they not understand systems? (Score:2)
"An almost limitless supply of fresh water exists in the form of water in human bodies, yet remains untapped, researchers said. 7.5 billion little water tanks, just walking around all the time. A human is 60% water, you can survive comfortably down to 54, maybe 52% on a good day. That's literally billions of liters of fresh water just waiting for us to find a use for it!"
Hint: just because something isn't evidently being used at the moment, doesn't mean it's not a critical part of a larger cycle.
Great Location for this (Score:2)
This technology could optimally be deployed adjacent to industrial facilities that use tons of seawater for cooling. Nuclear plants, data centers, heavy industry.
These place emit their "waste" heat as wastewater emitted from long pipes that go out to sea. Locally warmer seawater will emit more water vapor – increasing the freshwater harvest with no additional investment needed.
And as a bonus, emplacing this process near these waste-heat dumping sites would "cool" them in the sense that they would be w