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__The__Anomaly__ OP t1_j8ih9xi wrote

University of Adelaide’s Professor Shizhang Qiao and Associate Professor Yao Zheng from the School of Chemical Engineering led an international team that successfully split seawater without pre-treatment to produce green hydrogen.

Professor Qiao said, “We have split natural seawater into oxygen and hydrogen with nearly 100 per cent efficiency, to produce green hydrogen by electrolysis, using a non-precious and cheap catalyst in a commercial electrolyser.”

The team published their research in the journal Nature Energy.

A typical non-precious catalyst is cobalt oxide with chromium oxide on its surface.

Associate Professor Zheng explained, “We used seawater as a feedstock without the need for any pre-treatment processes like reverse osmosis desolation, purification, or alkalization. The performance of a commercial electrolyser with our catalysts running in seawater is close to the performance of platinum/iridium catalysts running in a feedstock of highly purified deionized water.

Professor Zheng added, “Current electrolysers are operated with highly purified water electrolyte. Increased demand for hydrogen to partially or totally replace energy generated by fossil fuels will significantly increase scarcity of increasingly limited freshwater resources.”

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FuturologyBot t1_j8im3rr wrote

The following submission statement was provided by /u/__The__Anomaly__:


University of Adelaide’s Professor Shizhang Qiao and Associate Professor Yao Zheng from the School of Chemical Engineering led an international team that successfully split seawater without pre-treatment to produce green hydrogen.

Professor Qiao said, “We have split natural seawater into oxygen and hydrogen with nearly 100 per cent efficiency, to produce green hydrogen by electrolysis, using a non-precious and cheap catalyst in a commercial electrolyser.”

The team published their research in the journal Nature Energy.

A typical non-precious catalyst is cobalt oxide with chromium oxide on its surface.

Associate Professor Zheng explained, “We used seawater as a feedstock without the need for any pre-treatment processes like reverse osmosis desolation, purification, or alkalization. The performance of a commercial electrolyser with our catalysts running in seawater is close to the performance of platinum/iridium catalysts running in a feedstock of highly purified deionized water.

Professor Zheng added, “Current electrolysers are operated with highly purified water electrolyte. Increased demand for hydrogen to partially or totally replace energy generated by fossil fuels will significantly increase scarcity of increasingly limited freshwater resources.”


Please reply to OP's comment here: https://old.reddit.com/r/Futurology/comments/1128bwn/scientists_successfully_split_seawater_to_produce/j8ih9xi/

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Cheapskate-DM t1_j8imt6d wrote

Worth noting cobalt is a conflict mineral, but it's a hell of a lot more affordable than platinum. This could be massive if implemented correctly. In addition to terrestrial applications, this could be huge for space-related applications where electrolysis of ice water is your primary source of oxygen.

Only issue is what to do with the brine/solids left after electrolysis.

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wwarnout t1_j8ir24q wrote

>Only issue is what to do with the brine/solids left after electrolysis.

...and this is not an insignificant consideration. If we're going to generate clean water on a scale necessary for many people, we'll have a lot of waste to deal with.

Still, getting near 100% conversion efficiency is a huge deal.

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frobischer t1_j8ivt1v wrote

Here's the abstract from the original paper in Nature Energy:
"The use of vast amounts of high-purity water for hydrogen production may aggravate the shortage of freshwater resources. Seawater is abundant but must be desalinated before use in typical proton exchange membrane (PEM) electrolysers. Here we report direct electrolysis of real seawater that has not been alkalised nor acidified, achieving long-term stability exceeding 100 h at 500 mA cm−2 and similar performance to a typical PEM electrolyser operating in high-purity water. This is achieved by introducing a Lewis acid layer (for example, Cr2O3) on transition metal oxide catalysts to dynamically split water molecules and capture hydroxyl anions. Such in situ generated local alkalinity facilitates the kinetics of both electrode reactions and avoids chloride attack and precipitate formation on the electrodes. A flow-type natural seawater electrolyser with Lewis acid-modified electrodes (Cr2O3–CoOx) exhibits the industrially required current density of 1.0 A cm−2 at 1.87 V and 60 °C."

https://www.nature.com/articles/s41560-023-01195-x

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BentasticMrBen t1_j8ixv4q wrote

ELI5: how is this relevant to the public? What are some of the direct affects this will have to humanity as a whole?

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Albert14Pounds t1_j8jape2 wrote

Can we not just discharge the brine back into the ocean? I don't really have an idea of the scale we would be dealing with but my gut tells me it's difficult to remove enough water from an area to significantly change the salinity. There's just a mind boggling amount of water out there

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GaudExMachina t1_j8jbx6v wrote

Over time that causes small salinity percentage changes in ocean water. While it would slowly diffuse into the oceans given turbity, in the short term it might destroy the local ecosystem. Many creatures are very sensitive to salinity changes. Accidentally kill off the base of the food chain or a keystone species and say goodbye to all creatures in those waters.

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RupaulHollywood t1_j8jdjh2 wrote

I'll explain like you're 15.

Hydrogen is envisioned by many in the clean energy sector (and the not so clean energy sectors) as a potentially powerful medium of energy storage as a chemical fuel. It has many potential applications if it can be produced cheaply at scale with green energy - steel and concrete production, sea-based shipping, aviation, grid scale energy storage, and several others. It can also be mixed into diesel engines to partially offset usage of carbon-based fuels, which is useful because diesel engines have service lives lasting decades. So hydrogen is a big deal if you're serious about decarbonization and knowledgeable about the challenges.

The problem is that pure hydrogen is rare - it's usually part of other molecules. To get hydrogen we have to split up those molecules. Water is very appealing because it doesn't emit greenhouse gasses as a byproduct - electrolysis of water splits it into hydrogen and oxygen using just electricity. But freshwater is a limited and dwindling resource. Seawater by comparison is plentiful. But it poses challenges for electrolysis - seawater is corrosive, seawater is impure, seawater is the domain of the Deep Ones and their dread flesh constructs. We simply don't have a great way to make hydrogen from seawater at an industrial scale.

This research presents a method by which to produce hydrogen from seawater that somewhat alleviates these challenges. It's early yet, but these are the kinds of things we need to figure out if we want to start building a real hydrogen economy and phasing it into those applications.

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Albert14Pounds t1_j8jf8r4 wrote

Where do you think that water is going? It goes back into the water cycle and eventually the ocean. We cannot possibly remove enough water from the ocean to make a significant change. Where would we put it? The hydrogen made gets burned and turns back into water which returns to the water cycle as precipitation.

Also you're not adding salt, the salt came from the ocean in the first place.

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Wilusan_00 t1_j8jmafw wrote

There is limit to the solubility of salt. It depends on the temp along w/ other factors. Even today there is much more salt/minerals in the oceans than water can hold. Extra salt/minerals turn into depozits. However that does not mean the brine is a problem. While the extra salt/minerals are solidifying, the brine wreaks havoc on the fragile ecosystems.

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JUYED-AWK-YACC t1_j8joco9 wrote

Discharge doesn't get sprinkled over all the water on earth, it comes out of pipes in real places. Those real places can't handle brine because it will kill everything around. Carthage anyone?

It's obvious you don't know anything, accept it and move on.

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seanbrockest t1_j8jqq1i wrote

Lol, do a little Google search for something called a potash tailing pile. Gigatons of free salt, usually a little contamination of potassium, clay, various carnalites, and sometimes some chemicals from the milling process, but still about 98% salt.

The problem is that salt is so INCREDIBLY cheap, it's not worth refining to get that 2% contamination out. It's usually cheaper to mine it in a more pure form, and then ship it a thousand kilometers to where it needs to be sold.

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ScottaHemi t1_j8js89p wrote

cool. now we just need the nuclear power to do this!

and even if we don't we just need the nuclear power...

why do they hate nuclear power D:

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Hvarfa-Bragi t1_j8jvill wrote

It doesn't have to come out of pipes in one spot.

Automated solar-powered barges could distribute ideal concentrations of massive amounts of waste salts.

Waste salts could be buried inland.

They could be used as building materials or for any number of other applications.

> It's obvious you don't know anything, accept it and move on.

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GaudExMachina t1_j8jy2hi wrote

>economic challenge,

That is what it really is. Storage on land would also be possible to an extent.
The best option would be to find a product/market to make out of the solids to offset the cost of moving it.

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dlamblin t1_j8jzchx wrote

I also don't get this claim. There's no chance that the amount of electricity used in the electrolysis can be regenerated 100% by using the hydrogen and oxygen produced.

It further doesn't seem to account for costs of pumping, storage, transport. Nor of handling the saltier byproduct brine. And that's really weird to the point of stupidity since they only have to take a cursory look at desalination plants to get some ideas about the issues at a production scale facility and approaches that can be applied.

Desalination of course is itself causing some issues in places like the [Persian/Arabian] Gulf, the Red Sea, soon the east Mediterranean.

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thisischemistry t1_j8k5twb wrote

It's also worth noting that even with a very efficient process it takes a lot of energy to split water into hydrogen and oxygen. In addition, the storage/delivery of the hydrogen takes a lot of equipment and energy, the hydrogen itself tends to escape easily and corrode equipment, and converting the hydrogen back into energy does not happen with 100% efficiency.

Hydrogen has a few key uses but it is really not a good replacement for most uses of fossil fuels because of these issues.

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thisischemistry t1_j8k6a2z wrote

> Even today there is much more salt/minerals in the oceans than water can hold.

No, not at all. Where have you heard something like this? The salts are dissolved in the water, they aren't supersaturated at all. Yes, they can precipitate out if conditions change but you can pretty much take a container of seawater and let it sit for a long time without any of it precipitating out.

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Viper_63 t1_j8kaafv wrote

Claims being made in the article are misleading and the research itself - which is actively being pushed on mutliple social media channels in a way that borders on the absurd - is massively overstated.

>“We have split natural seawater into oxygen and hydrogen with nearly 100 per cent efficiency

No, that's a BS claim. The process is not "nearly 100%" efficient. What they have actually done is that they achieved nearly the same efficiency as with conventional electrolysis using standard catalysts and pure water.

As per the abstract from the actual paper: >[...]and similar performance to a typical PEM electrolyser operating in high-purity water.

This whole thing - i.e. "we need to solve seawater electrolysis to make the hydrogen economy happen" is absolute BS, for the simple reason that the problem doesn't actually exist, because conventional electrolysis coupled with reverse osmosis (SWRO) is basically as efficient as it gets:

>Our analysis reveals there are limited economic and environmental incentives of pursuing R&D on today's nascent direct seawater electrolysis technology. As commercial water electrolysis requires a significant amount of energy compared to SWRO, the capital and operating costs of SWRO are found to be negligible. This leads to an insignificant increase in levelized cost of H2 (<0.1 $ per kg H2) and CO2 emissions (<0.1%) from a SWRO-PEM coupled process.

>https://pubs.rsc.org/en/content/articlelanding/2021/ee/d1ee00870f

"Direct electrolysis" results in insignificant gains. Purifying seawater is not what makes the process inefficient and not having to purify the water doesn't make it markedly more efficient let alone cost saving.

What's "preventing the hydrogen economy from happening" is not that we have to deal with seawater - it's that electrolysis itself takes massive amounts of energy and isn't efficient. You don't improve the underlying economic obstacles by slashing less then 10 cents from the price of a kg of hydrogen.

The "obstalce" is not seawater, it's the inefficiency of electrolysis. And the people pushing this research just told you that somebody has come with a way that's less efficient than regular electrolysis.

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phunkydroid t1_j8kahev wrote

Headline makes it sound like splitting seawater was the hard part that we couldn't do before.

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Viper_63 t1_j8kb1s2 wrote

The "nearly 100%" is in comparison to regular electrolysis.

From the abstract of the paper:

>[...]and similar performance to a typical PEM electrolyser operating in high-purity water.

The BS claim in the article is being used to push this research on social media. I don't know how many times I've come across this "news" in the last few weeks.

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JUYED-AWK-YACC t1_j8kcnro wrote

Increasing salinity in coastal areas is already a major problem for local governments. The associated damage is not hypothetical. When these plants are built, they won't be pie-in-the-sky technology but with whatever fits a tight budget. Don't fall in love with a single technical solution.

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metaphour t1_j8kiavp wrote

lol... sometimes I can't be convinced I don't live in a simulation. So we have a climate issue... that is melting ice caps... causing sea water to rise... and now we have a technology that would use that sea water to produce hydrogen? that's some homeostasis.

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Navynuke00 t1_j8kiffz wrote

Translation: the large utilities and oil companies see pushing a Hydrogen narrative as a great way to delay having to actually cut back on their natural gas infrastructure.

In all honesty, it's a red herring.

EDIT: bring on the downvotes. I work in this arena and this is something that's been discussed at length in more than a few places.

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Albert14Pounds t1_j8kjep6 wrote

Not comparable. The salt in this scenario came from the ocean in the first place and it's just going back where it came from. It's not like there's additional salt being added to the ocean or a significant amount of water being removed to make it more saline.

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Icy_Percentage1557 t1_j8kwd8m wrote

Sounds good. We don’t need water anyway. It worked really well with turning corn into ethanol too!

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SentorialH1 t1_j8kwgvl wrote

The problem we have with sea-water is what we do with the salt sludge...

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hyggety_hyggety t1_j8l2w42 wrote

Serious question: can someone explain to me why using our limited resource of water is a good thing? Like actually destroying the water. Why is treating our oceans as a new fuel source not a horrible idea? It feels like we’re a planet of fuel junkies trying for a better high.

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Nosrok t1_j8l57z8 wrote

What's the difference between the brine/solid leftovers and sea salt you buy at the store? I tried googling but not finding much.

I'd assume that people working on this are looking for alternative uses for the leftover material both for ecological reasons but also to help generate more money from the process.

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MegavirusOfDoom t1_j8la9md wrote

Wait till someone has an actual 1 year lab setup returning verifyable results. Energy breaking news is full of scams.

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hbHPBbjvFK9w5D t1_j8lmtlx wrote

compress it and use it as a substitute for concrete. Kill 2 birds with 1 stone, as concrete is one of the top producers of greenhouse gas.

Another good use would be to extract precious metals that concentrate in the slurry. The Japanese did it during WWII.

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Giantstingray t1_j8lne6x wrote

Brine has bee split to produce hydrogen,cl2 and ca2 forever what’s the news

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Giantstingray t1_j8loz6d wrote

It’s been done successfully for many years where do you think we get chlorine from

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Alpha3031 t1_j8lykw7 wrote

Well, they hydrogen doesn't go away when you use it as energy storage (it's not a fuel source because you get less energy out burning it than you put in unless you have some pretty advanced fusion reactor, it's like million times harder than deuterium fusion) so when you burn the hydrogen again you get water back.

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seaofmaddness t1_j8midjj wrote

What about the energy inputs? I thought that splitting water to produce hydrogen required quite a bit of energy, which is unlikely to be coming from carbon free sources.

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netz_pirat t1_j8mtfm2 wrote

While you are correct, the amount of water needed for green hydrogen is probably several orders of magnitude below the amount of water that we need to convert to drinking water - so we'll also see way less brine...

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DukeInBlack t1_j8mup4q wrote

Total BS, sorry for a couple of of very BIG reasons We just “borrow” water with law salinity and we will re introduce it in the cycle. There is very little water that is ever lost.

The total amount of human consumption of fresh water is just insignificant, not even measurable, with respect the total amount of water on this planet.

Bottom line: water does not exist in a “state” but in a dynamic cycle. Altering this dynamic cycle to a measurable amount requires a scale that is far bigger (many orders of magnitude) and does not take into account negative feedbacks to the process of increased salinity, like the increase of low salinity water coming from the waste product of this process

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nohwan27534 t1_j8mym9w wrote

Tbh I didn't think it was that hard, but then seawater has a lot of contaminants that could block the basic clean water plus electric idea I assumed was already well established.

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BentasticMrBen t1_j8n9fv0 wrote

I’m on board with what you’re saying, but will this still be a problem after a few years of successful clean hydrogen? As in aren’t they all just waiting to be proven wrong until they’re forced to change?

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Navynuke00 t1_j8nhx13 wrote

>but will this still be a problem after a few years of successful clean hydrogen?

We're still many years away from even being able to see the levels of hydrogen deployment that the large investor-owned utilities and fossil-fuel companies and industries are bragging about and hedging their carbon reduction goals on. And they're counting on that fact to be able to continue to kick the can down the road with existing fossil-fuel infrastructure, because it means they can keep their existing systems in place and make their stockholders more money by avoiding having to spend anything on capital improvement projects.

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BentasticMrBen t1_j8nl7sa wrote

The final squeeze of old energy has been and will always inevitably be messy and greedy. But it’s advancements like this that’ll try to make these squeezes final. What I’m saying is the car industry didn’t believe in clean energy, until technology and consumers demanded them to be. And now that technology is almost here for clean hydrogen, the next thing to do is convince the consumers of its benefits, and (hopefully) the industry will be forced to listen.

Clarification: I truly believe Reaganomics is on its way out, and the consumers will have a stronger sway on industry, rather than just CEO’s.

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Shadow122791 t1_j8o3d6n wrote

If green mean it puts out water vapor that is 50% of global warming like water vapor is then I guess they aren't to serious about climate..

As Earth also puts out 40% of green house gases by itself.... But that leaves us with 10% or less given new discoveries that made their natural output assumptions look pathetic....

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GaudExMachina t1_j8oawiq wrote

It really isn't. A few things to consider:
As I pointed out, the LOCAL effect is the most dangerous.

Infiltration rate of ground water into rock is relatively low, but recharge due to water permeability of rocks into aquifers is on the order of thousands of years. Which means when you take all that water and combust it somewhere else, a reasonable amount of it ends up going into recharge zones and being taken out of the "dynamic" cycle for a while. As well as being removed from the drainage basin feeding back into the soon to be hypersaline environment.

Plenty of research out there to show that very small salinity changes cause significant damage to ecological niches, though it is considerably more pronounced in freshwater systems, it still has far reaching implications in Salt water. Even a small percentage of change in the ocean leads to changes in the freezing point/dissipation rate which can disrupt weather patterns, change density of currents which carry nutrients and also provide turbidity.

You have zero idea about this topic, and are basing what you are saying on a notion that it FEELS like this is just too big to fuck up. And yet here are some things we have done that have fairly drastic impact....our world has been getting warmer since the industrial revolution. Denuding of forests for agriculture has caused drastic changes to groundwater runoff. Using Potash for fertilizer has caused massive algae blooms that have created dead zones in various places around the world. Hypersaline water has destroyed local fishing ecosystems around the Middle East where desalination plants have been very common for a long time.

Don't want to believe? Go do some research on Florida Estuaries and how the spawning grounds of quite a few important marine fish are being changed by salinity changes. (Only a tiny portion of these changes come from the handful of Desal plants Florida has, but the point is that salinity is still important).

Or here is a link of evidence in a local area of how desal plants hurt a sensitive biological marker species. https://pdfs.semanticscholar.org/142a/293bfa6e2e618b777ab328dacd3e33144908.pdf

I'm sure if you spent more than 5 minutes searching around, you would find plenty more.

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DukeInBlack t1_j8of98h wrote

This is a super niche effect that has been argued over and over many times before.

Yes, there are specific cases where the salinity increase was dangerous for the local, very local wildlife but all, repeat all the study refer to very specific ecosystems usually in freshwater or at the confluence of freshwater with marine water, as you correctly point out.

I argue that none of the proposed desalination plants fall on these categories and starting FUD campaigns based on very picked and chosen data is really dangerous and detrimental to the credibility of future valid arguments.

If you are an hammer does not justify treating everything like a nail. This post was about desalination on large scale. Do you want to post a warning on not dispersing back brine in high concentrations, fine, but proper disposal of brines is not only feasible but totally inconsequential

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GaudExMachina t1_j8ozdwr wrote

So, you admit I have some points, you want to argue over whether its super localized (again as I pointed out and gave alternative disposal scenarios in the original post) versus could have larger cascading effects, as we see in all kinds of complex systems. (See above about fertilizer usage spread on continent, killing marine fisheries)

But ultimately.....it is NOT BS. Not at all. You say as much, and continue to pretend it is all FUD, though it clearly has been "argued over many times" for good reason.

Thanks for your 2 cents......

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DukeInBlack t1_j8plu02 wrote

Arguing about possible cascade effects of brine disposal from large scale desalinization that are are not proven or not even studied is the definition of FUD and BS.

Look kid, I have been an environmentalist well before you were born and well before the whole movement become hijacked by law firms, media clickbait’s and politicians, protested pesticides and antibiotics well before it seems normal to do so but you or nobody should simply clump everything up in the same basket just because it has a possibility of harm even if it is an unmeasurable one.

Ecology is about resources and understanding If the human interaction with the environment but, most of all, is a quantitative discipline, like engineering.

We do not need any more demagogues or politicians but sound minded people and defendable data for any claim we make.

In the Gulf of Mexico there is an exposed salt deposit underwater that is worth several millions years of brine accumulation from providing 100 liters of water to 10 billions humans every day.

And it made by the exact same brine because was the effect of millions years of deposits of sea salts.

Any time an earthquake hits that region, an equivalent amount of many years of best desalination plants in the world gets released and change the ecosystem.

We need to stop shooting ourselves in the foot fighting every single insignificant battle and totally losing the war.

We were manipulated enough to kill the nuclear energy in the ‘70, did we not learn anything ?

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-Avacyn t1_j90pqxf wrote

As someone who is also working in this area, I am more hopeful. My company is setting up both the infrastructure for industrial CCS ánd hydrogen transport to connect off shore wind energy parks to on shore industrial clusters. First steps for realisations of both is planned for 2030, with quick expansion in the years after. Combining CCS with green hydrogen is very promising once the infrastructure is in place.

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