Marine biologists warn that widespread desalinization could take a heavy toll on ocean biodiversity because such facilities essentially vacuum up and inadvertently kill millions of plankton, fish eggs, fish larvae and other microbial organisms that constitute the base layer of the marine food chain. Also, for every gallon of fresh water produced, another gallon of doubly concentrated salt water must be disposed of, further wreaking havoc on marine ecosystems.
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Dear EarthTalk: With all the talk of desalinization of ocean water for drinking, what do we know about the impacts this might have on climate, ocean salinity and other natural processes?
-- Fred Kuepper, via e-mail
Due to its high cost, energy intensiveness and overall ecological footprint, most environmental advocates view desalinization (or desalination)‚ the conversion of salty ocean water into fresh water‚ as a last resort for providing fresh water to needy populations. Sourcing fresh water from streams, rivers, lakes and underground aquifers and adhering to strict water conservation measures are much more viable for both economic and environmental reasons in most situations, although some desert regions with thirsty and growing populations may not have many such options.
The relationship between desalinization and climate change is complex. Global warming has increased droughts around the world and turned formerly verdant landscapes into near deserts. Some long held fresh water sources are simply no longer reliably available to hundreds of millions of people around the world.
Meanwhile, expanding populations in desert areas are putting intense pressure on existing fresh water supplies, forcing communities to turn to desalinization as the most expedient way to satisfy their collective thirst. But the process of desalinization burns up many more fossil fuels than sourcing the equivalent amount of fresh water from fresh water bodies. As such, the very proliferation of desalinization plants around the world‚ some 13,000 already supply fresh water in 120 nations, primarily in the Middle East, North Africa and Caribbean, is both a reaction to and one of many contributors to global warming.
Beyond the links to climate problems, marine biologists warn that widespread desalinization could take a heavy toll on ocean biodiversity; as such facilities' intake pipes essentially vacuum up and inadvertently kill millions of plankton, fish eggs, fish larvae and other microbial organisms that constitute the base layer of the marine food chain. And, according to Jeffrey Graham of the Scripps Institute of Oceanography's Center for Marine Biotechnology and Biomedicine, the salty sludge leftover after desalinization for every gallon of freshwater produced, another gallon of doubly concentrated salt water must be disposed of can wreak havoc on marine ecosystems if dumped willy-nilly offshore. For some desalinization operations, says Graham, it is thought that the disappearance of some organisms from discharge areas may be related to the salty outflow.
Of course, as supplies of fresh water dwindle, the economic cost of desalinization‚ especially in coastal areas with easy access to ocean water‚ begins to look competitive with traditional water sourcing. To date there are about 300 desalinization plants in the United States, with 120 in Florida and less than 40 each in Texas and California. Some 20 additional plants are planned for the coast of California in the coming years, unless environmentalists extolling the virtues of conservation and wielding low-flow shower heads and toilets prevail.
CONTACT: Scripps' Center for Marine Biotechnology and Biomedicine, www.cmbb.ucsd.edu.
EarthTalk is produced by E/The Environmental Magazine. GOT AN ENVIRONMENTAL QUESTION? Send it to: EarthTalk, c/o E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; submit it at: www.emagazine.com/earthtalk/thisweek/, or e-mail: earthtalk@emagazine.com. Read past columns at: www.emagazine.com/earthtalk/archives.php.
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20 Comments
Add CommentOceans are not the only source of water that requires desalinization. Some lakes are naturally brackish and require the same process for drinking and use.
Reply | Report Abuse | Link to thishttp://tinyurl.com/lakekemp
I saw an article in Popular Science in the last year or so that described an evaporative desalinizer, that did not burn fossil fuels, had little to no moving parts, and yet provided plenty of fresh drinking water from the natural evaporative process of any body of water. What has happened to this design, and if it works, why is it not being implemented?
Reply | Report Abuse | Link to thisIn addition to my last comment - I seem to constantly see a disconnect in industries, where what one considers "waste", is often a necessary ingredient to another. Yet the "waste" is often disposed of, rather than redirected to another useful process. I am reminded of this by this article - the salt extracted from the process is returned to the ocean as "waste", potentially damaging the environment due to the higher salinity created. Yet here in the US in colder climates, we use tons of salt every winter on the roads to help prevent accidents (not necessarily the best practice, but this is just an example) - where do we get this salt? I would bet it is coming mostly from salt mines - and of course we all know that it will eventually make it's way via waste water back to the sea, adding to the net salinity. If we were instead using the "waste" salt from desalinization, not only would we be saving resources used to extract mined salt, but the net effect on ocean salinity would be reduced or negated due to only returning to the sea what was taken from it in the first place. If industries thought more along the lines of "who needs this" rather than "how can I get rid of this", I would imagine quite a few environmental impacts could be reduced.
Reply | Report Abuse | Link to thisIf you have to resort to desalination to quench the thirst of mankind you needn't be a scientist to understand there are simply too many humans on the planet. Devote more resources to population reduction in underdeveloped countries is the key.
Reply | Report Abuse | Link to thisthere should be batter ways go get fresh water, i heard of new plants that use algae and other types of filters to reduce waste both "gray water" and human waste. after this process we can retrieve a large percent of water used back into fresh water. although this might take a lot of energy solar is always a "green" type of way to get energy. i don't know enough about these type of topics so its always good to check the correct calculations and information somewhere else.
Reply | Report Abuse | Link to thispopulation reduction, you mean killing people? or do you mean have every other generation give birth? waiting till you are 50 years to have a children? just letting them die instead of feeding them? population reduction might be important but its impossible to do. you cant just kill people and not feeding them is inhumane. if your talking about people controlling others decisions usually through government for example that would be communism or at least a type of it. and if your talking about us controlling other countries decisions that would be unjust and unreasonable.
i think people are too worried about the economy and efficiency and that's why the world is having so many problems. like TNSciGuy said, "need to worry about who needs this instead of how to get rid of this" that is a good way to put it. just find every bit of waste we can try to recycle and reuse. plus if people where not so darn over payed then tons of problems would be solved. nobody needs to eat all day or sit around. but then the entire "democracy view is obliterated and is transformed into socialism. there is almost no good way to go about problems involved in the world.
Completely disagree alexdrudi. The surface of this planet is primarily water. It is extremely plentiful. Fresh water is a different matter. We're never going to "use up" all of the water since almost all of the water we do use eventuallt winds up back in the ocean way way or another.
Reply | Report Abuse | Link to thisI completely agree with TNSciGuy about reusing the excess salt from the process. Seems like a no-brainer. Also, to address fossil fuel concerns and global warming, why not couple future desalination plants with alternative power sources (solar maybe?).
Instead of poeple always talking about why we can't do things, how about coming up with innovative approaches to make it work in an acceptable manner?
alexdrudi, the problem is not the "underdeveloped" world. Its the developed nations rampant consumption that is to blame. So rather than population reduction in the 3rd world, we should advocate stomach reduction in the 1st world.
Reply | Report Abuse | Link to thisI think everyone talking about sustainability issues should state her own position on the following: "Is the world overpopulated?".
Reply | Report Abuse | Link to thisI notice those who disagree with me fail to be outspoken on this.
It's the attitude which keeps underdeveloped nations in the horrible situation they've consistently been in for decades.
Yes, "underdeveloped", because to be "developing" you should show some sign of improvement due to your own initiative and resources, not just increasing international support.
Nice inaccurate words don't solve problems, mask them.
And no, you needn't be starving to be allowed to make your own material situation better. I think having ten starving children is much more disgraceful than having a well-fed small family.
Way less people and better standards of living for all is definitely the way to go.
"it is thought that the disappearance of some organisms from discharge areas may be related to the salty outflow"
Reply | Report Abuse | Link to thisGold medal award for stating the bleeding obvious!
What's with the statement 'may be related'?
I strongly agree with alexdrudi's remarks, and not just for the developing world but also for the developed 'western' countries.
Reply | Report Abuse | Link to thisIt doesn't take an educated person to realise that if resource availability increases at an arithmetic rate, yet populations keep increasing at an exponential rate, people will suffer.
Women in the developed world have the advantages of birth control, education, and the ability to lead independent lives. The result has been a drop in birth rates below replacement levels in North America, Europe, and Japan (partly compensated by immigration from the third world).
Reply | Report Abuse | Link to thisI have no doubt that this will eventually happen in developing countries as well. Once women in the third world have the same opportunities, they too will have fewer children. Better living conditions in poor countries are the solution to the worlds overpopulation. Unfortunately, given the political turmoil in much of the world, this isnt going to happen any time soon.
great ideas,let's get our new administration to start listening to us. I think now we have people with open minds unlike the Bush boneheads.
Reply | Report Abuse | Link to thisResponce to tjams, There are methods and simple devices that bring WATER back to it's enate healthy state, that anyone can apply at home or on the farm.They are not filters, but they do work well with any filter system. The problem being that MOST people have such a limited understanding of Water and it's TRUE NATURE, that WATER is completly misunderstood and devalued. I'm Here to say that with a more basic and natural approach in processing Water, we will realize a more benefitial effect, from the WATER, because of the simple restructuring of the Water molecule,from H2 O to H3 O.The WATER becomes more bio-avalible. In all of my experiments with plants and small pets, I have realized one thing that I can always count on is, healthier, more abundant growth with plants, and healthier cats, dogs and goats. Not to mention my own health benefits, that I have been aware of for years now since installing 2 simple devices on my water lines in my house that creates a natural VORTEX in the WATER. This process made my WATER, softer, killed the chlorine smell and taste. I now build and sell my own Vortex Water systems that are helping to improve the vitality of WATER as well as do work shops to help educate people about the importance of healthy WATER..... Walter
Reply | Report Abuse | Link to thisThe use of desalination for human use does not have to be detrimental to the environment. For example, the middle east requires massive amounts of fresh water, yet the availability of fresh water is limited. Canada during the winter months requires very large amounts of salt which is used for deicing the highway system. The middle east can install solar thermal desalination units to provide water for their people, at the same time, have the brine continue to evaporate until nothing but the salts remain, and then collect them and sell to Canada for winter highway deicing. As a result, you eliminate the need for salt mining and provide drinking water at the same time. In response to the thought of large volumes of plankton and other small life forms being sucked into the system, simply use large pools connected to the ocean, with sand filters just like in a water treatment plant to prevent small life forms from entering the system.
Reply | Report Abuse | Link to thisThat's my take on the situation, evaporation is a natural part of the global water cycle, desalination by distillation is simply improving on nature.
Chris
www.bonsolaire.com
Reply | Report Abuse | Link to thisIt is possible to extract fresh water from the air.
In the Netherlands:
http://www.dutchrainmaker.nl/
And in Israel :
http://www.israel21c.org/bin/en.jsp?enZone=Technology&enDisplay=view&enPage=BlankPage&enDispWhat=object&enDispWho=Articles%5El2321
Make small units to provide a house all the water needed.
Of course: this is a partal solution.
A point not made is that desalination (for goodness sake, "desalinization" went out about 20 years ago) often employs waste heat from power stations. As the final paragraph of the article implies, building dams, pumping groundwater and other "conventional" supplies also take large amounts of energy. This has often not been costed fully when comparisons are made with desalination.
Reply | Report Abuse | Link to thisTHE WORLD IS NOT OVERPOPULATED
Reply | Report Abuse | Link to thisI believe that londoncalling and alexdrudi have a very luddite view of the world. The thought that population control (reduction I believe is the term that was used) is the only method possible to solve the problem is simply inhumane. You can not tell another group of people they are not permitted to have children simply because you think 10 children might eat more than 1 does. Many rural communities and families rely on their teenage children to help on the "farm" and this is common just as much in the western world as it is in the developing world.
Western economies are so stressed with their aging populations who just happen to have a never ending desire to consume, that they are relying on their so called third world former colonies to provide the workforce in order to maintain standard of living for the retired population who some how did not manage to have enough children to maintain growth in the economy. It is not the third world that is the problem, but the urbanized first world which consumes over 75% of the worlds resources but arguably has less than 25% of it's actual population.
The only way to over come the current problems is proper resource management. Proper management of land use, water use, energy use, and the use of agricultural production is necessary in order to reduce the problems of the world.
Case in point. Zimbabwe. That country was once a net exporter of agricultural food stocks and now is nearly in total collapse and starvation due to poor resource management.
Another nation. Israel, that nation uses a very small landmass which is mostly arid and poorly suited for agricultural production to produce a multitude of agricultural exports through the use of advanced irrigation and crop management.
If the nations of the Arabian Peninsula and Northern African countries of the Sahara were to use renewable technologies for energy, advanced irrigation methods including desalination of sea water and waste conservation methods such as total processing of sea water and collection of mineral salts which would result. They would be able to transform their desert nations into highly productive sustainable economies with export items ranging from mineral salts to high nutrient fruits and vegetables to any number of processed goods.
It is not over population that is the problem, but the lack of proper resource management and adaptation of technology, as well as the lack of political will that is at the root of the problem.
Christopher Towle
christophertowle@bonsolaire.com
Who to "bless & to blame" is irrelevant, an eco-friendly solution
Reply | Report Abuse | Link to thisfor resource avaliability would be constructive.
Small airconditioners produce a fair amount of water, could solar energy to a massive atmosfere conditioner be a "green machine"?
It should be noted that some sea water desalination plants do not have surface water intakes and instead rely on wells that offer water with low silt density and a constant chemistry. The problem of intake impingement and entrainment is not an issue. In addition concentrate (doubly salty waste) is injected into deep wells thus avoiding surface discharge sparing the osmoregulators. That being said, the many comments about using the concentrate are correct, but unfortunately it is not economic to do so until the value of the coastal flora & fauna have a price tag.
Reply | Report Abuse | Link to thisI appreciate the requirements for populations in arid regions but can anyone point me to the fuel requirement data for desalination, i.e. the cost in fossils fuels for a litre of drinkable water?
Reply | Report Abuse | Link to thisTIA Barry