[HN Gopher] Efficient method to capture carbon dioxide from the ...
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Efficient method to capture carbon dioxide from the atmosphere
Author : lrasinen
Score : 235 points
Date : 2025-12-31 13:59 UTC (9 hours ago)
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| cyphertruck wrote:
| Economics rules everything. How much does this cost vs simply
| planting trees, when the value of harvesting the trees is
| included? Since tree farms are generally profitable, and wood is
| expensive, it seems this method is likely to be economically less
| efficient.
| roflmaostc wrote:
| The problem is you cannot plant enough trees around the globe
| to offset our CO2 emissions. Also, a forest only absorbs CO2
| while alive. Once it dies, it emits CO2 too. You would need to
| permanently store the wood somewhere (submerging in water,
| etc).
|
| Recent article:
| https://www.theguardian.com/environment/2025/nov/28/africa-f...
| adregan wrote:
| One little appreciated fact is that trees also respirate CO2
| when they are cracking their stored sugars produced via
| photosynthesis. So they don't sequester all of the CO2 that
| they consume.
| OsrsNeedsf2P wrote:
| It's little appreciated since tree growth still consumes
| CO2
| adregan wrote:
| I suppose I'm pointing it out to highlight the trade offs
| with any of these solutions.
|
| What is unsaid is that we need to sequester CO2 for
| hundreds of years--often far beyond the lifespan of the
| trees. Trees are short term storage, and sometimes the
| storage is a lot shorter than popular imagination
| purports.
| thinkcontext wrote:
| Individual trees are short term storage which is why its
| important to create healthy ecosystems for them to live
| in. Turning denuded farmland back into a forest buffers
| carbon from the atmosphere for as long as the forest
| stands. It could stay there for centuries or return to
| the atmosphere if it gets bulldozed for a subdivision.
| xnx wrote:
| Biochar seems like a good option
| gs17 wrote:
| It's a hugely underappreciated option. I'm not sure how
| accurate it is (or how legitimate the companies doing
| biochar carbon removal are), but cdr.fyi shows biochar as
| the top carbon sequestration method that's actually
| happening.
| cogman10 wrote:
| It's possible to permanently capture the carbon if you turn
| the wood into charcoal and ultimately bury or store that.
|
| But left out to rot and yeah, the fungus and bacteria will
| ultimately consume the wood and release CO2 as a byproduct.
| Y-bar wrote:
| You don't need to convert it to coal. Use it to build
| houses, furniture, and other things.
|
| I am currently building a wooden house this way. Wooden
| frame, wooden exterior, wooden floors, even wood-based
| insulation (https://huntonfiber.co.uk/). The isolation has
| the shortest life span and it is expected to last at least
| 60 years.
| dylan604 wrote:
| If these forests are planted by humans, why do we think the
| dead trees would just be left to rot like you suggest vs
| being harvested for wood? The logic does not compute other
| than trying to make a ridiculous point.
| arkensaw wrote:
| using the wood for heating also releases the CO2. I do
| think planting trees is a good idea, but it's worth
| pointing out they can be a carbon source even after
| harvesting, depending on the usage.
|
| On the other hand if the wood is used for construction or
| furniture it will not emit.
| thinkcontext wrote:
| I think this loses the forest for the trees. That is, a
| single tree rotting isn't what matters its how long the
| ecosystem the tree is part of lasts. Consider a square
| kilometer of denuded land turned back into a forest. You
| can think of the forest as a temporary storage for carbon,
| its stored in the trees, soil, animals, insects, etc in
| that square kilometer. Individual trees may die but on
| average if the forest remains in good health there will be
| a number of tons of carbon kept out of the atmosphere.
| loeg wrote:
| What do you think happens to harvested wood?
| dylan604 wrote:
| why do you think it will only be used as fuel? it can
| also be used to build things with it
| loeg wrote:
| I didn't say fuel. It also rots when used as a building
| material.
| dylan604 wrote:
| Then you've built poorly. That's not the wood's fault
| nephihaha wrote:
| Trees have advantages that go beyond bureaucratic aspects of
| environmentalism.
| fsckboy wrote:
| _I think that I shall never see a poem lovely as a tree._
| -- Joyce Kilmer
| manoDev wrote:
| Planting trees solves both the carbon capture and the
| emissions issue from different angles. Some examples are:
|
| - With more wood available it's more economical to use it as
| a building/manufacturing material over other emissive sources
| (concrete, steel, plastic)
|
| - We can replant the same area multiple times
|
| - Even if we plant crops for biofuels, it's closer to carbon
| neutral than burning fossil anyway
|
| Every move we can make towards planting (and managing) more
| of the surface of the Earth is an improvement, without
| waiting for miraculous new technology.
| gus_massa wrote:
| I agree. Plants are not very efficient (1% or 2%) but they
| include packaging the CO2 in a stable form. You can store the
| grain or wood for long periods of times.
|
| In this case, it looks like they get CO2 as a gas. It's cheaper
| because you don't have to use energy to undo the burning, but
| it's difficult to store for a long time.
|
| (I'm not sure if someone tried to make a fake underground bog
| in abandoned mine. Just fill with wood and water to keep the
| oxygen low and make the wood decompose slowly.)
| cjbenedikt wrote:
| Take a look at "wood vault". 'Wood vaulting': A simple
| climate solution you've probably never heard of | Grist
| https://share.google/lS8xnMGEd1pMzlNg2 Economically not
| attractive but apparently very efficient in locking up CO2.
| adrianN wrote:
| The problem with any scheme to capture and store carbon
| from the atmosphere is the incredible amount of carbon
| we've blown into the air in the last 150 years. Just look
| at the size of the machines we use to harvest coal.
| Essentially you'd need to have machines of similar size
| working for many decades to re-bury the carbon we extracted
| and burned. Who's gonna pay for that?
| dheera wrote:
| > stable form
|
| Not really, forest fires happen and then a few hundred of
| years of sequestered CO2 gets released back in an instant.
|
| Organic material with oxygen gas floating around is not
| stable.
|
| Sequestering carbon into the ocean might be a better
| strategy. Not flammable and not subject to stupid capitalism
| effects around land prices.
| lefra wrote:
| The ocean has already absorbed 30% of the CO2 humanity has
| emitted. It causes issues: ocean acidity rises, which
| reduces plankton ability to grow. Plankton being the base
| of the ocean food chain, all ocean life gets impacted.
|
| You'd need to find a way to sequester carbon without it
| leaching in the water.
|
| https://marine.copernicus.eu/ocean-climate-portal/ocean-
| carb...
| dheera wrote:
| Random idea: What if we just sequestered it into
| elemental carbon pellets and let it sink to the bottom of
| the ocean? It should not react with the water.
| S3verin wrote:
| Planting trees is not effective since it takes decades to
| capture the carbon, but the next years are crucial for
| determining long term climate developments.
| adammarples wrote:
| There is no carbon capture technology on earth that can be
| rolled out at a scale over the next few years that can
| compete with planting trees. Especially not one that has just
| been invented in one university. Ash grows 90cm per year,
| that's all carbon. Scale that to millions and billions.
| yodon wrote:
| >Economics rules everything
|
| Physics rules everything, once you start trying to run at
| scale.
|
| The density of carbon per unit volume in solid materials of
| interest doesn't vary that much, whether you sink it in trees
| or in exotic materials like diamonds. That means you can
| calculate the volume of material required so sink a desired
| amount of atmospheric carbon.
|
| If you want to have a measurable impact on the atmosphere, say
| dialing it back to 1980 CO2 levels, you're talking not about
| making a pile of stuff but about making a mountain range that's
| a mile high and hundreds of miles long.
|
| Now figure out how many trucks you're going to need to move
| that much material from where your sequestering machine is to
| where your pile of stuff is.
|
| Or if you want to dump that material in the ocean (which
| someone else will certainly object to), extend your calculation
| to figure out how many container trucks worth of material you
| need to dump into the ocean every hour to accomplish your
| atmospheric cleanup in whatever amount of time you choose (a
| decade? If it takes a century, that's not fast enough).
|
| And finally think about surface to volume ratios. You're trying
| to sink it into a volume, but you can only get the gas into the
| volume through its surface, so the speed of your process is
| limited by surface area.
|
| If you want to do it with trees, my personal spitball estimates
| are that you probably need to plant somewhere between the
| entire state of Connecticut and the entire state of Colorado to
| have the kind of impact one would want (there's more subtlety
| to tree calculations than one generally likes to admit, so feel
| free to come in with way higher numbers than I did).
|
| Which brings us back to economics. If you have a well-managed
| forest of that size and scale, someone is eventually going to
| come along, maybe in 100 years, maybe in 500 years, and say
| "hey if we cut this down, we could burn the wood to heat our
| homes" and all that carbon goes back into the atmosphere, so
| you actually need to sink it into something that is
| energetically unfavorable for recovery, which means you also
| need to expand a huge amount of energy to sink the carbon into
| that energetically unfavorable state.
| marcosdumay wrote:
| > you're talking not about making a pile of stuff but about
| making a mountain range that's a mile high and hundreds of
| miles long.
|
| Just to put it into numbers, wikipedia has the total amount
| of CO2 on the global warming page, if we assume it's in a 2
| kg/l substance it totals to around 180 km^3.
| three14 wrote:
| But if you release the O2 and convert it into diamond, then
| by my highy-suspect back of the envelope calculations, it'd
| be a diamond that would fit into one square kilometer, 87
| meters high. It would make quite the tourist attraction.
| marcosdumay wrote:
| My number is without the O2.
|
| It's a literal mountain chain of plastic. We do have uses
| for it, but it's a lot.
| carbonguy wrote:
| To put it further into numbers -
|
| 1). Wikipedia does have a citation [1] saying 2,450
| gigatonnes of CO2 have been emitted by human activity, of
| which 42% stayed in the atmosphere and 34% dissolved in the
| oceans, with the rest already sequestered by plant growth
| and land use. As we start to pull CO2 out of the
| atmosphere, it will begin to be emitted from the oceans as
| well; therefore, let's assume we have to recapture all
| excess atmospheric and oceanic CO2:
|
| :: 2450x10^9 tonnes CO2 x .66 fraction to sequester ~=
| 1.6x10^12 tonnes CO2.
|
| 2) Let's convert the CO2 to something more stable for long-
| term storage: HDPE.
|
| - Convert mass of CO2 to mass of carbon:
|
| :: 1.6x10^12 tonnes CO2 x 12/44 mass fraction of C in CO2
| ~= 4.4x10^11 tonnes C
|
| - Convert mass C to mass HDPE; assume HDPE is effectively
| (CH2)n. Then:
|
| :: 4.4x10^11 tonnes C x 14/12 mass fraction CH2 to C ~=
| 5.2x10^11 tonnes HDPE
|
| 3) That's a lot of plastic! How much volume? Wikipedia says
| HDPE is ~930-970 kg/m3; let's be conservative again and
| take the low figure:
|
| :: 5.2x10^11 tonnes HDPE x 1.0/0.930 m3 per tonne HDPE ~=
| 5.5x10^11 m3 HDPE
|
| 4) Those are cubic meters; how about cubic kilometers?
|
| :: 5.5x10^11 m3 x 1.0/1.0x10^9 km3 per m3 ~= 5.5x10^2 km3
|
| In other words, if you turned all the [excess potentially
| climate-change impacting] CO2 that humanity has emitted
| since 1850 into plastic (a process that would certainly
| emit a large additional CO2 fraction given the industrial
| buildout required) then we'd end up with about 550 cubic
| kilometers of the stuff. Coincidentally, that's about the
| volume of Mount Everest according to an intermediate
| calculation in [2].
|
| So, a mountain of carbon: more than a pile but less than a
| mountain range.
|
| [1] https://en.wikipedia.org/wiki/Carbon_dioxide_in_the_atm
| osphe...
|
| [2] https://www.quora.com/What-would-the-estimated-weight-
| of-Mou...
| sokoloff wrote:
| If we pull this off, I would not expect people 500 years from
| now to undo it.
| tzs wrote:
| If we took _all_ the CO2 out of the atmosphere and converted
| the C into graphite and spread that uniformly over the top 10
| subtropical deserts it would be around 2 cm deep.
|
| This suggests a long term approach of building solar powered
| carbon capture plants in subtropical deserts, they capture it
| and convert to graphite, which is then spread out under the
| solar panels.
|
| I once did the math on this, using the specs for currently
| available solar powered carbon capture, and it came out to
| something like if we used 100 years worth of the current
| production annual production of solar panels for this we
| could carbon capture at a rate that could drop the atmosphere
| from current levels of CO2 to pre-industrial levels in a few
| years even if we do _not_ reduce emission rates.
|
| So...not practical now, but might be feasible as a very long
| term project that over many decades builds out enough
| capacity to get things under control as long as we can keep
| everything from going to hell over that time.
| Yizahi wrote:
| In the order of importance:
|
| 1. Even if we do magic and emit nothing, we still need to
| remove CO2 from the atmosphere or it will cook us over time,
| just longer.
|
| 2. We would need an enormous area for forests (which i great),
| which would mean a lot of intervention, like resettling people,
| demolishing and constructing new buildings, a lot of machinery
| time to move people to and from the new forests, a lot of
| planting and forest maintenance involved. And add he work to
| cut and bury resulting wood. If you would sum all the
| incidental emissions from this process it would rapidly become
| much less efficient (if at all).
|
| Without either CO2 capture or a sun shade of some sort, the CO2
| levels and temperature will only ever increase, just like now.
| jacquesm wrote:
| > it will cook us over time, just longer.
|
| The largest sous-vide cooking pot ever...
| Detrytus wrote:
| This solves only part of the problem: it captures CO2 and can
| release it later. But you still need to figure out what to do
| with this CO2, how to turn it into something useful.
| mnky9800n wrote:
| you can inject it into peridotites and let it mineralize. there
| is enough exposed peridotite outcrops in the world that we
| could inject all the co2 produced and store it there
| indefinitely. this process also produces elemental hydrogen.
| cjbenedikt wrote:
| Do you have any links on research on that? Serious question.
| gus_massa wrote:
| Someone proposed to make giant beaches of malachite and let
| the sea break the rocks. Malachite has two -OH that can be
| replaced by a CO3= and so capture the CO2.
|
| I can't find a good link now, but at least it's the only
| method I know where it's not obvious that requires a huge
| amount of energy that makes the whole process net negative.
| mnky9800n wrote:
| Yes.
|
| For example:
|
| https://www.pnas.org/doi/10.1073/pnas.0805794105
|
| Peter Kelemen has written a lot of papers on this topic.
|
| Here is a more recent paper that I wrote together with
| Peter and others currently in review:
|
| https://eartharxiv.org/repository/view/9651/
|
| This is more about the mechanics of how the rock breaks to
| allow fluids to move around.
|
| And here is another paper currently in review that we
| coauthored about how we know there's gas moving in the
| system and therefore hydrogen is being produced:
|
| https://essopenarchive.org/users/543018/articles/1363688-en
| i...
|
| Tbh I have no idea why we didn't submit these to arXiv
| instead of these other preprint servers.
| Gravityloss wrote:
| Thank you for this, it's very illuminating and awesome
| news.
|
| I think it's worthy of its own submission as well
| (besides being very on topic on this subject here too).
| mnky9800n wrote:
| I would be happy to have my papers on the front page of
| hacker news lol. So far it doesn't happen.
| probably_wrong wrote:
| I'm fine with keeping it inside something brick-shaped and
| chucking it down an abandoned mine from where it can be
| retrieved at a later time. It would definitely be a storage
| improvement over "the atmosphere and our lungs".
| S3verin wrote:
| It can be used as an energy storage by compressing / releasing
| + powering a turbine. Good for storing excess wind + solar
| energy.
| NetMageSCW wrote:
| If it is reasonably energy efficient, this could be used to
| feed a methane processor, especially on Mars.
| nozzlegear wrote:
| The answer is obvious: create a cryptocurrency-based economy
| where countries and citizens are incentivized to pull CO2 out
| of the atmosphere and ship it into space in exchange for
| crypto.
|
| /s
|
| One of the subplots from the excellent Delta-V series by Daniel
| Suarez.
| jnsaff2 wrote:
| Stable storage would be limestone. To bring it down to pre-
| industrial levels it would mean that each person on earth would
| get a cube of 5 meters a side.
|
| IDK, build houses out of limestone like we have been doing for
| ages.
| HPsquared wrote:
| Roads maybe?
| pgrohe wrote:
| A startup from Quebec is using an electrochemical process to
| produce potassium formate from CO2.
|
| Electro Carbon https://www.electrocarbon.ca/en
|
| https://sustainablebiz.ca/clear-the-runway-electro-carbon-be...
|
| Their process for generating potassium formate is greener than
| standard methods. It does require electricity as an input but
| that can come from renewable, green sources.
|
| Potassium formate is used in de-icing products, fertilizer,
| heat transfer fluids, drilling fluid, etc... so a useful,
| monetizeable output comes out of the process.
|
| Disclosure - Know the founders personally. Wanted to shoutout
| their work. No financial ties to the company.Chemistry is not
| at all my expertise & I don't have details on their process
| beyond what's on the website.
| net01 wrote:
| What are the use cases of CO2 appart for making my Coke fizz?
| adregan wrote:
| The main commercial use is enhanced oil recovery--shooting it
| into old wells to extract more oil (super ironic if captured
| from the air).
|
| One application I think is neat is that it's a pretty robust
| refrigerant in a heat pump application.
| cjbenedikt wrote:
| You can combine it with H2 to produce synthetic fuels. Not
| ideal but could reduce fossil fuel use and hence new CO2
| released.
| HPsquared wrote:
| Third ingredient missed out: lots of energy.
| nkmnz wrote:
| The reaction of 3 H2 + CO2 -> CH3OH + H2O is exergonic, so
| the H2 already brings all the energy needed.
| quickthrowman wrote:
| Off the top of my head, CO2 can be used as a solvent for dry
| cleaning, it can extract THC from cannabis, and can also be
| used as a refrigerant.
| n49o7 wrote:
| As I understand it, the main driver behind current carbon-
| capture tech is selling carbon credits.
| PunchyHamster wrote:
| You can add hydrogen and make methane for those industries that
| can't easily electrify
| marcusb wrote:
| It is used as a shielding gas in some welding processes
| (notably, MIG welding.)
| black6 wrote:
| Plant food.
| istjohn wrote:
| Dry ice blasting
| potato3732842 wrote:
| You can think of industrial CO2 use as basically the same as
| nitrogen but a little worse and several fucktons cheaper.
|
| CO2 is fairly inert. This makes it useful. Welding steel is a
| typical example of something you can use CO2 to shield. There
| are many other examples in the chemicals industries of things
| like that where you want to do something at a "higher than
| natural on earth" temperature to make a reaction happen or
| happen faster but you don't want that reaction to happen with
| oxygen all around.
|
| And on the other end of the temperature spectrum....dry ice.
| goda90 wrote:
| Supercritical CO2 turbines:
| https://energy.wisc.edu/industry/technology-highlights/super...
|
| On a much smaller scale I've been hoping for a small solar
| powered CO2 compressor to exist so I could use it for mosquito
| traps. The state of the art for those right now is burning
| propane for the CO2 combined with a scent emitter for the human
| smell to attract female mosquitos.
| Gravityloss wrote:
| Synthetic food is a potentially big one.
|
| Synthetic materials is another. For example carbon electrodes
| for batteries.
| condensedcrab wrote:
| Direct air capture imo can't escape the scaling problem - when
| the feedstock has CO2 at ~400 ppm the economics simply won't work
| out despite various oil companies backing one off systems around
| the globe.
|
| Capturing CO2 at the source (power plant, etc) would be simpler
| to reach economic viability but without incentives it's dead on
| arrival. I believe the IRA infra bill had put a price ~$50/ton of
| CO2 captured.
| jmclnx wrote:
| I agree, plus were would one store the CO2 ? To get back to
| "1980", I really doubt puling CO2 from the atmosphere will ever
| work.
|
| Another concern, who will pay for maintenance ? See this for
| why you cannot let CO2 escape from underground storage:
|
| https://en.wikipedia.org/wiki/Lake_Nyos_disaster
|
| If stored near a populated area, hundreds of thousands could be
| kill, including all animals and insects, in a matter of minutes
| if the "vault" has a catastrophic failure. I would rather live
| near a nuclear waste site than a CO2 Site.
| gonzo41 wrote:
| Well as far as storing it goes, if you can capture it, turn
| it into a solid and stick it in the ground.
|
| Imagine you were growing a huge biomass that you harvest, dry
| out, and then store. We know how the bacteria and processes
| that stripped co2 from the atmosphere in the past, we just
| need to do that in a big way. Good thing we have places on
| earth that are huge and flat and growing algae won't be a
| problem.
|
| And then we complement that with green energy and an attempt
| at net zero.
| teiferer wrote:
| As long as leading figures either claim it's a hoax or that
| it's not necessary to do sth about it, none of this matters
| anywhere.
|
| This is less of a technogical problem than it is a
| political one, I'm afraid.
| literalAardvark wrote:
| Not exactly less.
|
| It's a science fiction grade engineering problem and a
| historically unprecedented political problem. That's a
| tough mix to crack.
|
| It's worth trying to delay the end of civilization, but
| reversing this is literally like putting the fire back in
| the Molotov.
| teiferer wrote:
| > I would rather live near a nuclear waste site than a CO2
| Site.
|
| If it's between immediate death and a slow one of cancer, I'm
| not sure your choice is the obvious one.
| pigpop wrote:
| A failure in containment at a nuclear waste storage site
| means danger for people on the site itself but it is easily
| detected by monitoring equipment and can be repaired, the
| waste is solid and can't spread easily. A failure in
| containment of a massive quantity of pressurized CO2 would
| be significantly more dangerous and probably a lot more
| likely to happen given the frequency of accidents
|
| https://aiche.onlinelibrary.wiley.com/doi/abs/10.1002/prs.6
| 8...
|
| https://www.youtube.com/watch?v=zkWeZ1YPI88
|
| https://www.youtube.com/shorts/H1rWZHNWBWo
| mixedbit wrote:
| Can't we just store C and let the O2 back in the air like
| plants do? We could store it right where it came from, in old
| coal mines.
| thinkcontext wrote:
| Chemical reduction of CO2 is a very hard problem since it
| takes a lot of energy. There's an enormous amount of
| research in this area. Storing it costs money, so most of
| the research focuses on turning the C into a useful
| product.
|
| https://en.wikipedia.org/wiki/Electrochemical_reduction_of_
| c...
| Teever wrote:
| But we still need to remove all the excess co2 that we released
| into the atmosphere since the start of the industrial
| revolution if we want to reduce the temperature back to what it
| was before we started disrupting the natural state of the
| plane.
|
| We and previous generations took out a loan and the payment is
| coming due.
|
| Because of the framing about degrees in celcius change people
| are thinking in small numbers, like "oh, it's just 1.5'C over
| normal. oops, we missed that, well maybe we'll get it at 2.0'C.
| They don't realize that if we want normal we ahve to _reduce_
| the temperaure and to do that we need to take that c02 blanket
| off that we 've been tightly wrapping around our collective
| bodies for decades.
|
| And that endeavor is nearly unfathomable. Think of all the
| energy used by humanity since the industrial revolution _and_
| the energy we 're going to be producing in the time period that
| we attempt to sequester the previously poduced C02. All of that
| needs to be accounted for.
|
| And then there's the surplus energy roiling around in the
| system now, and the collapse of food webs.
|
| I don't see how we get our way out of this in the next 50
| years.
| condensedcrab wrote:
| That's true. It's more of a policy issue that's like carbon
| credits... nice on paper but a big nothing burger. Look at F1
| and Porsche talking about sustainable synthetic fuels.
|
| When you compare round trip efficiencies and economics it
| makes sense to just not burn the hydrocarbons to begin with.
| raverbashing wrote:
| Yes
|
| For the atmospheric one, grow trees and algae
| teiferer wrote:
| With ice caps melted off, just removing all the excess CO2
| isn't even enough since with that reflective surface gone,
| more energy from sunlight stays in the atmosphere than
| previously when more of it was reflected back into space
| instead of nowadays being absorbed by the ocean.
| Teever wrote:
| Absolutely. People seem to think that we just need to
| recycle more, seal some cracks in the house with foam,
| install some solar panels, and buy an electric car.
|
| They underestimate the scale of the intervention that will
| be required to stave off the potential end of human
| civilization as we know it. If we have any hope of
| continuing to live at something resembling the quality of
| life that we've grown up in it will require radical science
| fiction like developments.
|
| We're going to need things like space based solar shades to
| regrow glaciers and icepack, advanced breeding and cloning
| and ecosystem engineering to reconstruct collapsing food
| webs, and I think the big picture thing is that we're going
| to need to engineer people to reduce susceptibility to
| addictive food and manipulative marketing.
| teiferer wrote:
| > If we have any hope of continuing to live at something
| resembling the quality of life that we've grown up in
|
| Chances are, developed countries won't be hit that hard,
| at least for a generation or two.
| marcosdumay wrote:
| Capturing CO2 at the source will always be worse than removing
| the source. At the same time, capturing CO2 from the air will
| stay necessary until we do it.
| elil17 wrote:
| A better title would be "More efficient method to capture CO2
| from the atmosphere." The method is not objectively efficient,
| but may be more efficient than other methods (solvents/sorbents)
| used for DAC.
| HPsquared wrote:
| Yes it's important to distinguish "efficiency getting closer to
| theoretical maximum" from "actually cheap and economically
| feasible".
| comicjk wrote:
| I gave my engineering students a CO2 removal design problem
| once, and at the end, asked why the theoretical efficiency had
| increased in the time since the textbook was written. The
| answer was that the concentration of CO2 in the atmosphere was
| higher.
| sfn42 wrote:
| The thing people don't think about with regards to CO2 capture is
| that you have to get the atmosphere in order to capture CO2 from
| it. You essentially have to suck the entire atmosphere into these
| carbon capture facilities.
|
| Using something like this to capture carbon from an exhaust pipe
| might be viable, but scrubbing CO2 out of the atmosphere is not
| even remotely viable. There's just too much air out there.
| cjbenedikt wrote:
| You can actually capture CO2 from sea water thereby reducing
| ocean acidification and improving its capability to continue as
| our planets biggest CO2 sink.
| roflmaostc wrote:
| there's also lots of water to wash then.
|
| The problem is the same, the relative concentration of oxygen
| in air is less than 0.05% (~450pars per million). In water
| much less.
| sfn42 wrote:
| Well here's the thing - there's quite a lot of water out
| there too.
|
| How long and how many terawatts of power do you think it'll
| take to suck a significant fraction of the earth's seawater
| through a capture facility?
| nilamo wrote:
| You're right, it's expensive and hard, so it's better to
| not do anything and... migrate all humanity onto space
| stations so we don't die with the earth, I guess is the
| alternative you're suggesting?
| umeshunni wrote:
| The earth doesn't die because CO2 levels increase. There
| have been multiple epoch with higher CO2 concentrations
| than we have now.
| sfn42 wrote:
| Never in the history of the planet has the temperature
| increased anywhere near as quickly as it's doing now.
|
| If you look at a chart of historic temperature levels,
| pretty much every significant change on that chart
| corresponds to a mass extinction.
|
| So yes, the earth does die. The earth has died many times
| before and it's currently happening again. The rock
| itself will still be here but us and pretty much
| everything else that lives here will be wiped out by
| climate change. The only question is how long it will
| take, and as you can see it's going fast.
|
| This is not controversial, except for ignorant people who
| refuse to face the facts. This is what climate scientists
| have been warning us about for our entire lives.
|
| Doesn't matter whether you believe it, it's happening.
| sfn42 wrote:
| It's not expensive and hard, it's impossible. The largest
| carbon capture facility in the world is called mammoth,
| and in order to offset our current emissions we would
| need a million of them. We can not build a million of
| them.
|
| This is why climate scientists have been saying for a
| hundred years that we need to stop producing all this
| CO2, because we can't take it back. We can't just fix it.
| We can't just get back all the ice that's melted and
| keeps melting, we can't unthaw the permafrost. We can't
| stop all the methane and other climate gases that have
| been trapped under ice for millions of years from being
| released and making it even worse. We just can not do it.
|
| We were warned, we ignored the warnings and now we're
| seeing the consequences.
| j_maffe wrote:
| Gasses diffuse through the air very quickly. Having a few high-
| volume extraction points would be enough long-term.
| sfn42 wrote:
| Yeah except the highest volume facility in the world is
| called mammoth and in order to offset our current emissions
| we would need a million mammoths.
|
| Even if you could make it a thousand times more efficient it
| would be a stretch.
| condiment wrote:
| At current rates of emissions, we're only about 20 years away
| from people needing to install CO2 scrubbers in their homes.
|
| Soda lime, or calcium hydroxide, is the current state of the art.
| We use that in an anesthesia and in saltwater aquariums and in
| scuba rebreathers. An idealized system can capture 500 mg per
| gram, but in practice you only capture around 250mg/g. This
| outperforms the method in the article but it's one-shot. There
| are interesting proposals to use this for direct capture at
| industrial facilities and to turn the waste material into bricks
| for building.
|
| The key advantage of this new material appears to be that it can
| be heated and reused. That would be very valuable in an interior
| direct air capture use case. Think about filtering the CO2 from
| an office or a home to get us back to pre-industrial levels
| indoors.
| yodon wrote:
| Do you have a citation for that 20 years estimate?
| netcraft wrote:
| I was also a bit skeptical, but chatgpt gave a pretty good
| answer I think: https://chatgpt.com/share/69553e26-ea28-8011-
| bc17-8658fbea4e...
|
| Buildings with higher people/sqft could already take
| advantage of indoor co2 scrubbers today.
| idiotsecant wrote:
| https://en.wikipedia.org/wiki/Carbon_dioxide_in_the_atmosphe.
| ..
|
| Just extrapolate.
| marcosdumay wrote:
| https://gml.noaa.gov/ccgg/trends/
|
| Extending the current exponential for 20 years, we get into
| the 500ppm region.
|
| I don't think that's enough to need scrubbers.
| Ringz wrote:
| Indoor is always higher ppm (how much depends on many
| parameters) without proper ventilation. ,,Proper" should
| include a ,,Heat exchanger" thus you don't need to reheat
| fresh air.
| marcosdumay wrote:
| Still, it will add some 80ppm over the amount you have
| today. There's a huge amount of disagreement over how
| much CO2 is harmful, but it tends to happen over numbers
| way above 800ppm.
|
| If your room has 2 times the open air concentration, and
| you are concerned if it's 2.0 times or 2.2 times, you
| should already be dealing with the problem.
| literalAardvark wrote:
| It's not way above, it's around 700+.
|
| So at 500 external you'd pretty much need continuous ERV
| but not necessarily scrubbers just yet.
| mort96 wrote:
| According to https://www.co2meter.com/blogs/news/carbon-
| dioxide-indoor-le..., at 1000 ppm people start getting
| drowsy. Let's assume that a decent indoor environment has 300
| ppm more CO2 This means that our threshold for when people
| start getting drowsy even in decent indoor environments is
| when atmospheric CO2 reaches 700 ppm. For reference, it is
| currently around 420 ppm, and pre-industrial levels were 280
| ppm.
|
| From https://www.climate.gov/news-features/understanding-
| climate/..., the pessimistic projections suggest that we may
| reach our 700 ppm threshold by roughly 2070; 45 years from
| now. (The graphs are hard to read precisely)
|
| The 300 ppm offset compared to the outside air is naturally
| just an arbitrary number, everything up to 1000 ppm (meaning
| everything up to 580 ppm more than atmospheric levels) is
| considered "acceptable". That means any increase in CO2
| concentration will take an indoor environment which used to
| be considered "acceptable" and make it cross the threshold
| into "unacceptable". An indoor environment which would've
| been at 900 ppm around the industrial revolution (280 ppm)
| would've crossed the threshold when we surpassed 380 ppm
| (which was in 1965 according to
| https://www.statista.com/statistics/1091926/atmospheric-
| conc...).
|
| let's compare the past 20 years. In 2004, the concentration
| was ~377 ppm. That's 47 ppm lower than what was in 2024. An
| indoor environment which was "borderline but acceptable" at
| 955 ppm CO2 in 2004 would've crossed the arbitrary 1000 ppm
| threshold by now, and therefore would benefit from a CO2
| scrubber. The next 20 years will likely have a higher
| increase than the past 20 years, so there will be a larger
| range of currently acceptable indoor environments which will
| cross the 1000 ppm threshold by 2045.
|
| TL;DR: It's complicated, 20 years is arbitrary, but as CO2
| concentrations increase, indoor quality gets worse so indoor
| environments which were already bad will become worse. 45
| years is a more realistic estimate for when your typical good
| indoor environment will become unacceptable, but it's a
| gradient.
| netcraft wrote:
| 160F, non toxic, this already sounds like something that could
| feasibly be used in the home. I would already be interested in
| installing one. And would absolutely love to see what it would
| do to school performance.
|
| The hard part is capture and disposal.
| adrianN wrote:
| You can heat definitely heat NaHCO3 to get CO2 and NaOH back.
| It just takes a lot of energy.
| 29athrowaway wrote:
| Maybe we just need to make cyanobacteria that multiplies
| faster.
| UniverseHacker wrote:
| I think it's little appreciated that high CO2 levels cause
| cognitive impairment, and with the same amount of (often very
| poor) air exchange, higher outdoor concentrations can push
| indoor spaces to levels that cause impaired cognition and poor
| sleep. I've already been seeing this in my home, and will often
| open windows even when cold just to keep co2 levels reasonable.
| One solution that can help is an external air heat exchanger,
| which can exchange air with the outdoors without compromising
| your homes heating and cooling like an open window will do.
|
| Noticeable cognitive impairment starts in the 700-1000ppm
| range, whereas it is very common for homes to reach
| 2000-3000ppm, especially when in a closed bedroom.
| lokar wrote:
| Really? Wow, I try to keep my place at 500-600, without that
| much effort.
| malfist wrote:
| I find it extremely unlikely that homes are routinely at
| 2000-3000 ppm. That is extremely high and would mean
| multiple people in a small area with no air exchange for a
| long while.
|
| I monitor my indoor co2, but don't take any action because
| it's extremely rare to be above 700 or 800. I can only
| remember a handful of times its reached 1k ppm. And my
| house should be prime candidate for co2, it was built
| during the era of "seal all air gaps" but before ERV or
| HRVs. I also use pressurized co2 to inject co2 into a
| planted aquarium. And my dogs are terrified of open windows
| so they are rarely open.
| jhpankow wrote:
| Homes in the upper midwest are well-sealed and insulated.
| Bedrooms can hit 2,000 ppm with two adults sleeping in
| them.
| cassepipe wrote:
| If we are three in my small living room in winter (around
| 20m2), it easily climbs above to 2000ppm in less than an
| hour
| stavros wrote:
| My bedroom regularly gets to 3000 at night, and the flat
| in general is around 2000. This is in the winter, when I
| don't open the windows for days because of the cold. The
| flat is very well insulated.
| mapt wrote:
| It happens a lot in efficient houses that don't cover all
| bases with HVAC (the vast majority of recently built
| houses), where the room door is closed, maybe the vents
| are not ideal, and there is usually no makeup air or
| forced air ventilation other than a furnace intake.
|
| This change in scientific literature actually causes a
| ~quadrupling of recommended airflow ratios for tight
| homes versus ASHRAE's previous guidelines, putting strong
| emphasis on an ERV. Previously, ventilation needs tended
| to be dominated by air quality and smell, by humidity
| buildup, or by theoretical house parties that maxed out
| the system.
|
| This ventilation adds capital expense, but it's
| substantially more controllable and significantly cheaper
| in the long run in colder climates than 'just open a
| window' or 'just don't build the house so tightly
| sealed'. Reserve the operable window for the
| aforementioned house party, which is out of a reasonable
| design envelope.
| ekianjo wrote:
| > high CO2 levels cause cognitive impairment
|
| Sounds seriously unlikely. How would this work in practice,
| at the level of bodily functions?
| MathMonkeyMan wrote:
| I don't know the mechanism, but:
| https://www.google.com/search?q=co2+cognitive+impairment
| nehal3m wrote:
| >One solution that can help is an external air heat exchanger
|
| I have one of those, it blows fresh air in through the
| bedroom and sucks it back out through the kitchen (loft
| house, this route prevents food smells from wafting into the
| bedroom). Aside from just feeling fresh all year, this system
| also prevents mosquitoes from entering in summer while still
| allowing air circulation, it automatically bypasses the
| exchanger at night to provide cool air and it has some pollen
| filters installed which helps with hay fever.
|
| So great economic return and a bunch of upsides, but it does
| require space for the exchanger and the ducts throughout the
| house.
| mrspuratic wrote:
| This. I have that type (regenerative MHVR) installed in the
| attic for upstairs, and a synced pair of in-wall ceramic
| (recuperative) types on opposite sides of main living area
| downstairs (eliminating ducting, albeit with reduced
| efficiency). I haven't attempted any energy/ROI
| calculations but fresh filtered air, lower humidity and
| good nights sleep are well worth the claimed single-digit
| watt power usage to me.
| hinkley wrote:
| I suspect bathrooms aren't big enough to buffer the air
| pressure but it seems like we should design the air
| handling so the "fan" is always on in the bathrooms. Maybe
| a split between several places and taking a bit from the
| cold air return for the rest.
| nehal3m wrote:
| The system is always on and moving air as a whole, and
| the water closet and bathroom have an intake duct that
| sucks in humid air that goes to the heat exchanger for
| exhaust. I have a little humidity sensor hooked up to
| Home Assistant that kicks the fan in the exchanger into a
| higher gear and returns to auto when humidity returns to
| baseline.
|
| All rooms in the house have an intake or exhaust duct
| depending on requirements.
|
| There is also a small control panel next to the
| thermostat in the living room that controls the whole
| system for when, ahem, your number two's are particularly
| odorous (or you're using the kitchen to cook for 6).
| deadbabe wrote:
| Ok this sounds like BS, what kind of sensor is being used to
| get such readings? What do you use?
| bluerooibos wrote:
| I used an Awair Element after wondering if Co2 buildup was
| causing my groggieness in the morning and an ever so slight
| dull headache.
|
| My bedroom was quite small at the time, but I measured the
| same effect of buildup in a larger bedroom, just the Co2
| level took a little longer to reach it's peak.
|
| In the small room it took about 45 mins to climb to about
| 1400 after I closed the door and went to sleep.
|
| I'm currently trying to install some above-door vents to
| improve circulation but this is a topic most people don't
| consider at all, even though studies have shown the effects
| of classrooms having high Co2 concentrations on exam
| results and cognition.
| lawrenceduk wrote:
| We monitor air data quite closely at work.
|
| CO2 rises really fast with people in even a large space.
|
| I wouldn't put too much effort into vents above a door as
| we've seen that CO2 will leak through doors and even
| floors/ceilings very quickly.
| deadbabe wrote:
| When was it calibrated?
| ctoth wrote:
| > higher outdoor concentrations can push indoor spaces to
| levels that cause impaired cognition
|
| I am somewhat skeptical of this:
|
| https://www.astralcodexten.com/p/eight-hundred-slightly-
| pois...
| cassepipe wrote:
| I have been monitoring for high CO2 for a few months now. I
| easily find myself in the 1000 - 1400 range for some time
| before I finally let some air in in winter.
|
| I have not noticed significant cognitive impairment (not
| saying it did not happen)
| wcoenen wrote:
| > _Noticeable cognitive impairment starts in the 700-1000ppm
| range_
|
| The US navy failed to detect such effects in submarine crew,
| even at much higher levels like 10,000 ppm.
|
| Another reason to be skeptical is that exhaled breath is 4%
| CO2 (40,000 ppm!). Therefore a few thousand extra ppm in the
| inhaled air should not make much of a difference to the
| homeostasis mechanisms in our bodies.
| progbits wrote:
| See my sibling comment for meta-analysis that disagrees
| with you. Would love to see citation for those navy
| experiments.
| wcoenen wrote:
| Citation for a 2018 study with submarine-qualified
| sailors: https://pubmed.ncbi.nlm.nih.gov/29789085/
| hinkley wrote:
| Have you ever met a submariner? These are not normal
| humans. That's some serious cherry picking of data.
| hinkley wrote:
| Back in the 00's I worked at a place where we were still
| ignoring WLB and would work until seven a couple nights a
| week on average. But the building AC shut off at 6. A few
| of us noticed that the later it got the worse our
| decisions and the worse the bickering and we eventually
| got to the policy that anyone could declare Deciding done
| for the evening when they realized we were just tired,
| hot, and stuffy. Every minute past about 6:15 got worse,
| particularly in summer.
|
| I'm sure the CO2 was part of it but lack of circulation
| also means increasing temperature, especially with a
| bunch of people in a small meeting room. Long meetings
| themselves are a problem and any excuse to call it early
| is probably worth it even if it's not entirely true.
| UniverseHacker wrote:
| I don't need to look at studies in other people, I notice
| and feel the effects directly at high CO2 levels, such that
| I can tell when it it too high before checking the meter.
|
| I'd need to look at the study, but I also suspect the
| submariners would be used to high CO2, and also not
| experienced enough in doing focused creative or knowledge
| work for impaired abilities there to be detectable.
| ifwinterco wrote:
| This is a meme on hacker news that's usually stated as a
| fact, but I'm not sure there's any robust evidence of
| cognitive impairment at <1000ppm
| progbits wrote:
| https://www.sciencedirect.com/science/article/pii/S03601323
| 2...
|
| > In this study, a systematic review and meta-analysis of
| fifteen eligible studies was performed to quantify the
| effects of short-term CO2 exposure on cognitive task
| performance.
|
| > The complex task performance declined significantly when
| exposed to additional CO2 concentrations of 1000-1500 ppm
| and 1500-3000 ppm
| codeulike wrote:
| Additional
| ifwinterco wrote:
| It looks like there might be a very small effect starting
| at around 1000ppm but so small that many studies find no
| difference at all, and reliable effects are only noted at
| 3000ppm or more.
|
| So we're a long way from needing to scrub co2 from the
| atmosphere to get any work done
| progbits wrote:
| Not from atmosphere but we need good ventilation. Over
| 2000ppm in offices is very common.
| ProllyInfamous wrote:
| My quality of sleep/life have greatly increased since
| installing an Energy Recovery Vent (ERV) -- it exchanges
| outside/inside air through a membrane, which is about 60-80%
| efficient for both humidity and temperature re-capture
| (depending on fan speed).
|
| [*] <https://en.wikipedia.org/wiki/Heat_recovery_ventilation#
| Ener...>
|
| I use a Panasonic model -- readily available from Big Box
| Retail (~$700 + $100 in vent/conduit) -- which can do 20 - 60
| cfm (in my 900 sqft home this can easiliy exchange the entire
| volume several times per day).
| thangalin wrote:
| > I think it's little appreciated that high CO2 levels cause
| cognitive impairment
|
| Have you been telling representatives? Here's a letter I
| wrote to mine:
|
| https://pdfhost.io/v/bRJEGptatL_climate-change
| jiehong wrote:
| Could something like this be used to make cement?
|
| Imagine capturing CO2 to turn it into cement, used for
| constructions.
|
| Pardon my ignorance, though.
| bobfromhuddle wrote:
| We don't use CO2 to make cement, we use limestone, and CO2 is
| the byproduct of heating the limestone to make reactive
| calcium.
| henearkr wrote:
| Do you know ferrock?
|
| It is a kind of cement that uses CO2 to cure.
| henearkr wrote:
| You can store CO2 and sell it to construction companies (to
| cure ferrock), to energy storage companies (who like to put
| the CO2 in huge bubbles nowadays, go figure), or to
| agricultural corporations (who enrich greenhouses air in CO2
| to accelerate growth).
| marcosdumay wrote:
| > The ease of releasing CO2 is the key advantage of the new
| compound.
|
| I have no idea why the journalist that wrote this article
| choose to highlight the carbon density of the sub-header. It's
| almost completely irrelevant for carbon capture plants.
|
| Another clear benefit is that it's a liquid.
|
| Today people mostly use the substances that you called non-
| reversible in research plants (AFAIK, all plants are research
| right now). They are perfectly reversible, but that uses a lot
| of energy.
| nine_k wrote:
| > _perfectly reversible, but that uses a lot of energy_
|
| Looks like a perfect match to a solar plant, which provides
| basically free energy periodically. All you need is a large
| enough cistern to hold the liquid during night time.
| marcosdumay wrote:
| Yes, it's a great match to solar plants.
|
| But you don't need to store the capture medium. You use a
| bit more energy to make they work faster while the Sun is
| shining, and stop everything when it's gone.
|
| The largest bottleneck is what you do to get rid of the
| CO2.
| eisfresser wrote:
| We use the CO2 to synthesize methanol with the H2 we
| electrolyze using surplus solar energy. The methanol we
| burn in winter for heat. Yes, that releases the CO2
| again. The goal here is not to save the planet. It is to
| bring solar energy to winter. My house produces many
| times the electricity that it needs per year, but most of
| it is wasted in summer. Efficient conversion is not a
| factor. If I can get 20% of the energy input back as heat
| in winter, it is worth it: that is oil or wood I don't
| have to burn for heat.
| nine_k wrote:
| I mean, you have to recycle the CO2-carrying liquid. You
| have to store some of it that has CO2 captured but not
| yet recycled because the Sun is down.
| omgJustTest wrote:
| citation for the co2 scrubbers in home need?
| DivingForGold wrote:
| "outperform" by only one metric too often fails usefulness.
| It's a one shot unless you heat the calcium carbonate to 900C,
| the compound in the article only requires 70C, and has quite a
| bit of ability to re-process CO2 absorption multiple times.
| Although solar ovens could reach over 900C, probably too
| dangerous for residential use.
| bilsbie wrote:
| Just to counter your extreme prediction, if co2 levels halve
| from here all life on earth goes extinct.
|
| https://www.researchgate.net/post/Minimum_necessary_concentr...
| loeg wrote:
| They aren't at risk of halving, though?
| gspr wrote:
| Please stop trying to hurt every single human being with
| these derailments. There is no plausible mechanism by which
| carbondioxide levels would halve. That means you're just
| trying to derail the discussion by appealing to people's
| instincts about how fragile atmospheric composition is. Stop.
| keepamovin wrote:
| I have an efficient method. It's called plants. Amazon is re-
| greening
| PeterHolzwarth wrote:
| Well, instead of repeating myself manually, I'll paste in a
| comment of mine here from a past discussion on carbon capture:
|
| It's easy to forget why there is a bit of a challenge to getting
| C02 out of the air: there's so little of it, comparatively.
|
| In order, air is, broadly, made up of the following:
|
| Nitrogen: %78.084
|
| Oxygen: %20.946
|
| Argon: %00.934
|
| CO2: %00.042
|
| The stuff is essentially beyond a rounding error - it really
| gives one an appreciation of the "either don't release it, or
| capture it at the point of release" sentiment, and for the
| difficulties in making carbon capture outside of these scenarios
| be even slightly cost-effective.
| saubeidl wrote:
| What if one started emitting Nitrogen, Oxygen and Argon in the
| right proportions instead to get the mix right again?
| dotancohen wrote:
| These gases are refined from air to begin with.
| saubeidl wrote:
| Do they need to be?
| avianlyric wrote:
| Where else are they going to come from? They're all basic
| elements, either you separate them from air, or you have
| to go through an energy intensive process to liberate
| them from various chemicals they've been compounded into.
|
| But guess what, all of those chemicals are extremely
| valuable, such as nitrates for fertiliser, water, and
| Argon does really react with anything (it's a noble gas),
| which is why we use it as a shield gas in processes like
| welding.
|
| So producing enough of those gases to somehow offset CO2
| production would first require ludicrously large amounts
| of energy, and if we had access to that amount of clean
| energy we wouldn't even be having this discussion. Plus
| it requires breaking down really valuable chemicals that
| we spend quite a lot of energy trying to produce or
| preserve anyway.
| hannob wrote:
| Where would that come from? It's not that we have some
| large untapped Oxygen or Nitrogen source laying around
| that is not part of the atmosphere.
| GZGavinZhao wrote:
| My naive guess is that since CO2 takes up so few percentage,
| you would need an unfathomable amount of N, O, and Ar to get
| the mix right..?
| the_gastropod wrote:
| Think about the magnitude you're talking about here. Every
| internal combustion engine on earth is emitting CO2. Every
| volcano, forest fire, coal power plant, etc. The atmosphere
| is _massive_. We've been, basically, doing our best to pump
| it full of CO2 for the last 150 years, and this is what we've
| got. Ignoring the chemical challenges with your idea here,
| the scale is impossibly gargantuan.
| hannesfur wrote:
| Interesting thought but you would need a _lot_ of these
| gasses on the one hand and on the other hand it doesn't help
| in working against the greenhouse effect. The greenhouse
| effect depends on the absolute amount of CO2 in the
| atmosphere, not the percentage. How much infrared light is
| absorbed by CO2 primarily depends on the amount of CO2 in the
| atmosphere.
| mort96 wrote:
| We will unquestionably reach more than twice the CO2
| concentration of pre-industrial levels (which was around 280
| ppm; we're at 424 ppm now, it'll increase to beyond 560 ppm
| in most not-super-optimistic projections).
|
| Do you really think it's both feasible and a good idea to
| release so much O2 and N2 to _double the mass of the
| atmosphere_? Or even just increase it by some appreciable
| fraction?
|
| For the record, the atmosphere is around 5 150 000 000 000
| 000 metric tons. 5 _quintillion_ kilograms. You 're talking
| about producing _metric exatons_ of gas.
|
| Wikipedia says that there's 300 000 to a million gigatons of
| nitrogen in the earth's crust; that's 300 teratons to a
| petaton (https://en.wikipedia.org/wiki/Nitrogen#Occurrence).
| If you extracted LITERALLY ALL THE NITROGEN IN THE CRUST,
| converted it to nitrogen gas and released it into the
| atmosphere, and we use the extremely optimistic 1 petaton
| estimate, you'd have increased the mass of the atmosphere by
| roughly 1/5000. That means you'd have decreased the CO2
| concentration in the atmosphere ... by roughly 1/5000. From
| 424 ppm to 423.92 ppm.
| anotherpaulg wrote:
| I like the unconventional approach. A few minutes with GPT
| raises two issues:
|
| 1. We've raised CO2 from 280ppm to 420ppm, about a 50%
| increase. To dilute it back down would require 50% more total
| atmosphere. This would also raise the surface air pressure
| 1.5x.
|
| 2. How much heat is trapped is related to the absolute amount
| of CO2 in the atmosphere, not the fraction. So the diluted
| atmosphere would retain just as much heat.
| vscode-rest wrote:
| Would it increase the steady state surface air pressure by
| 50%, or would more molecules offgas into outer space to
| compensate?
|
| If the latter, it might actually work. Assuming they offgas
| at-proportion. Which they probably wouldn't...
| caturopath wrote:
| Plants seem to manage it okay.
| hannob wrote:
| They don't, and they can't cheat physical realities either.
|
| Plants only filter out very small amounts of CO2 from the air
| over relatively long timeframes. That's why crop-based
| biofuels require such enormous amounts of space.
| leobg wrote:
| So then, is it really the CO2 that produces the cognitive
| impairment, or is the CO2 here just the proxy value that we are
| measuring, and the real reason for the cognitive impairment is
| low oxygen?
| xboxnolifes wrote:
| If the amount of CO2 is basically a rounding error, so too
| would be the reduction in oxygen.
| kzrdude wrote:
| You could climb a mountain to test your hypothesis, keeping
| an eye on partial pressure of O2
| loeg wrote:
| We have a natural experiment. People in Denver aren't
| especially stupid.
| rdruxn wrote:
| It's also the metabolic changes in pH. CO2 is a proxy for ph
| as carbon dioxide acidifies the blood as it dissolves.
| nradov wrote:
| Nitrogen also causes cognitive impairment. It is essentially
| a very weak anesthetic. If you can replace all of the
| nitrogen in your breathing gas with helium then you'll
| probably gain the equivalent of a couple IQ points (although
| obviously that isn't generally practical).
| thunderbong wrote:
| I get what you're saying, but couldn't this be used in a place
| with high concentrations of CO2, like factory chimneys?
| cwillu wrote:
| That would be "capture it at the point of release"
| verytrivial wrote:
| Indeed. I've always had trouble picturing how to efficiently
| "unmix the cake" too. CO2 is rare and throughout the whole
| atmospheric column. What kind of concentration gradient can you
| get going to meaningfully pull it out from _everywhere_ in
| human timescales? (Sorry if this nerd-snipes someone stronger
| with calculus than me.)
| IshKebab wrote:
| Also more fundamentally it's always going to be more efficient
| to not produce CO2 than to unproduce it.
|
| Ok maybe in a small number of circumstances there's no other
| option (e.g. planes), but mostly you're _far_ better off
| spending your energy making solar, wind, batteries, heat pumps,
| insulation etc.
| BurningFrog wrote:
| It's hard to put my finger on why, but that's a really weird
| way to frame the situation.
|
| For one thing, most of us don't control any CO2 production we
| can turn off.
|
| Also, even if/when we finally produced our last CO2 molecule,
| the excess CO2 will last for many centuries, and we really
| should get it back to lower levels.
|
| With good capture tech, you can keep keep doing some
| important CO2 producing activities.
|
| Sure, it seems very unfeasible with current technology, but
| that is bound to improve as you work on it.
| rwke wrote:
| Without knowing much about the details of it, this might be
| interesting to evaluate as a potentially economically more
| attractive alternative to DAC in the supply chain of e-fuel
| production?
| jmward01 wrote:
| I am not against doing research in this area, please do, it is
| interesting and likely has many applications but global CO2
| removal isn't one of them. Nothing proposed, including this, is
| within any orders of magnitude of a viable solution. The only
| solution we have is put less in the air in the first place. This
| tech looks interesting for transporting CO2 but that doesn't mean
| it sequesters it and even if sequestration was solved the scales
| here are massive. If we don't have the political will to reduce
| the amount going into the air then what makes anyone think we
| would have the political will to build out some system to capture
| and sequester? We need to focus more on not putting CO2 into the
| air and less on trying to take it out.
| nine_k wrote:
| Sequestering CO2 where it's highly concentrated, e.g. at power
| plants or cement factories exhausts, would be one way to emit
| less.
| LargeWu wrote:
| I've wondered if capturing carbon emissions from industrial-
| scale compost facilities would be a net positive. It would
| have the added benefit of the carbon initially being captured
| by natural organic processes (i.e. growing food), so it
| avoids the problem of the energy requirements from trying to
| just pull carbon from the ambient atmosphere. I don't know if
| this is feasible but I haven't seen any research on it.
| nine_k wrote:
| What we need to offset the last 3 centuries of coal use is
| to reverse the process. Plant large amounts of trees, cut
| them, burn the hydrogen part of them, producing char and
| reclaiming some energy, then bury the resulting coal back
| in the abandoned coal mines.
| LargeWu wrote:
| Yeah, that too. There's not going to be one single
| solution, the problem is just too big for that. The idea
| with compost is that growing plants for food and dealing
| with the waste and excess (which is substantial) is
| something we're already doing, so can we tack carbon
| sequestration on top of that
| mikestorrent wrote:
| > burn the hydrogen part of them
|
| Could you elaborate
| fodkodrasz wrote:
| I guess Coke.
|
| https://en.wikipedia.org/wiki/Coke_(fuel)
| mikestorrent wrote:
| How are we getting that out of a tree
| nine_k wrote:
| https://en.wikipedia.org/wiki/Charcoal
|
| Did you ever do a barbecue? You first burn the light,
| hydrogen-rich substances of the firewood, with a large
| beautiful flame; that flame would burn down the meat, but
| it burns off quickly. What remains is charcoal, the
| source of most heat in the firewood; it does no produce a
| visible flame, but emits _a lot_ of heat. It is mostly
| carbon.
| TSiege wrote:
| This is called Carbon Capture and Storage and so far it has
| never been worth it energetically. And the only companies
| doing it are oil companies in a process known as enhanced
| recovery which pushes more co2 out than is pushed in. The OP
| was right. Better to leave it in the ground
| nine_k wrote:
| You can have 100% renewable energy. You can't realistically
| produce cement or steel without using and exhausting large
| amounts of CO2. This has to be addressed, even if it costs
| energy (which, as we agreed, can be 100% carbon-neutral).
| teknopaul wrote:
| I think OPs point is this tech is good only if you sink it
| after.
|
| I. e. Collection is half the problem.
|
| Collecting it in a way it's cheap to get it back again is
| potentially just less than minus half the problem.
| teknopaul wrote:
| Did a bit of searching: fizzy drinks companies sometimes go
| and get stored CO2 to put in drinks or make it.
|
| Any atmospheric extraction has a net positive compared to
| that.
| graeme wrote:
| We'll need this tech later. If and when we get emissions to net
| zero we'll still have too much CO2 in the air. Better to have
| begun the research now.
| ctoth wrote:
| > If we don't have the political will to reduce the amount
| going into the air then what makes anyone think we would have
| the political will to build out some system to capture and
| sequester?
|
| Because political will requires coordination, building systems
| and turning them on doesn't have to!
|
| > We need to focus more on not putting CO2 into the air and
| less on trying to take it out.
|
| What part of the "we" in _this_ coordination problem doesn 't
| require political will?
| ctoth wrote:
| The implicit model in "just emit less" is that human
| coordination problems are easier than engineering problems.
| That's historically backwards. We're extremely good at
| building things. We're terrible at getting everyone to
| sacrifice simultaneously for diffuse future benefits. Please
| generalize this!
| teknopaul wrote:
| Covid proved this generalisation is not a truism.
|
| USofA was probably the only place that actively resisted
| the global effort.
|
| I think people do want a better world. Greed is not
| universal. Most countries that grow a middle class find
| most people prefer to stop work. I.e. there are not that
| many infinitely greedy humans. And they can be taxed.
|
| Despite neocon economic theory, most people aren't selfish.
| And those that are, are often happily rewarded with a
| plaque in their honor or a medal.
|
| Just look at the length Trump goes to for an award.
| rayiner wrote:
| COVID didn't cost anyone anything in terms of improved
| standard of living. Curbing emissions growth would do
| that.
|
| People aren't "greedy," but my family in Bangladesh
| absolutely wants to live like my family in America, or at
| the very least like my family in Canada. They don't
| consider that "greedy" and if you tell them it is they'll
| laugh at you.
|
| The country's CO2 emissions per person have increased by
| a factor of 5x since we left in 1989, consistent with per
| capita GDP going up by 10x. Even on an efficient
| development path it's going to go up another 5x in order
| to increase the country's GDP per capita another 10x,
| which will put it at the level of a poor eastern european
| country like Hungary or Croatia. That's the earliest
| anyone is even going to listen to you about CO2
| reduction.
| schoen wrote:
| Maybe with nuclear power? Are you already factoring that
| in under "an efficient development path"?
| ethbr1 wrote:
| > _USofA was probably the only place that actively
| resisted the global effort._
|
| Really? China, Indonesia, Iran, South Korea, Italy, UK,
| Brazil, Tanzania, North Korea, etc.?
|
| Making the COVID response sound like one global
| cooperative endeavor is some serious retcon'ing.
| teknopaul wrote:
| The is one trick that doesn't require political will. If you
| can make the microeconomics work it can be made to scale it
| self.
|
| E.G. Make CO2 extraction so cheap it's worth everyone doing
| it and say, make a market to sell the CO2 to farmers. Then
| make burying inedible bits of plants so cheap it's done on a
| large scale.
|
| Then you just wait. Microeconomics takes over.
|
| They did this with plastic clean up. By building a machine
| that makes plastic into fuel & construction pellets. Then
| stuck such a machine on a plastic poluted island and waited.
|
| For this trick. All you require from your politicans is that
| they don't lie or bomb the place.
| nxpnsv wrote:
| Buried plants make methane...
| aaronblohowiak wrote:
| We need this even if emissions went to zero overnight. World is
| a big place, can do more than one thing at a time.
| maddmann wrote:
| Unfortunately, Technological solutions are more politically
| feasible than attempting to reduce via restrictions and
| regulations that require intense global coordination that does
| not exist.
| lenkite wrote:
| Maybe we need to genetically engineer special of trees that are
| active only during the day and sleep at night. Photosynthesis
| at daytime and Dormancy at nighttime for maximum CO2
| conversion.
| vasco wrote:
| There's no general will, it's not specifically political will.
| Emitting less CO2 means doing less things or doing them for
| much more money due to high taxes to discourage it (and also
| disproportionately affect poor people). Other than some
| luddites I've never met anyone that genuinely was willing to
| sacrifice eating a nice steak or going on vacation unless they
| are millionaires, and that's only because those people know
| they can do it as much as they want. You have a huge mass of
| people getting lifted from poverty that will tell you to fuck
| off if you tell them that now they are finally out of eating
| rice and starving they can't have a steak, because of CO2.
|
| All the things silicon valley "caviar communists" say you need
| to stop doing are basically the dreams of a whole mass of
| people coming out of poverty. Nice food, traveling, having a
| car, having A/C, etc.
|
| So we can either find alternatives, or slowly figure out more
| geoengineering projects like mass absorbing CO2 and the like.
| wincy wrote:
| I grew up in a trailer, and last month I flew halfway across
| the country and ate at a Michelin star restaurant that fed me
| truffles flown from Italy.
|
| I am definitely part of this group you describe.
| fillskills wrote:
| There are 4 different categories of fixing the global CO2
| challenge: a. Remove CO2 from atmosphere b. Prevent adding new
| CO2 from reaching atmosphere
|
| This could also be a good use case for #b where CO2 is captured
| before being released to the atmosphere. For example factories
| and vehicles could be mandated to use this.
| imoverclocked wrote:
| There are applications where weight still makes battery storage
| impossible. By capturing carbon, we may give ourselves the
| ability to harvest fuel from the air instead of the ground.
| Given the sometimes negative cost of electricity, this could
| make it more cost effective to do so. If we replace fossil fuel
| drilling with sequestration then we are at net zero.
|
| This may be part of the solution ... or maybe we find a way to
| make a utopia where we can all agree to just stop polluting.
| Historically, the utopia has no precedent that I am aware of.
| akshatjiwan wrote:
| I think you have a point. It could be difficult to justify the
| cost of carbon capture based on sequestration alone. One of the
| reasons I think this might still work is that captured carbon
| can be used to create platform chemicals (various hydrocarbons)
| using the fischer tropsch process. Electrofuels are using
| direct air capture to generate fossil replacements.
|
| Only requirement is energy and there too it isn't all that
| expensive to pull air in from the atmosphere or to seperate CO2
| from adsorbent via low grade heat (70-100c)
|
| So far into the future this method could allow us to continue
| produce critical hydrocarbon materials (used everywhere from
| plastics to pharamaceuticals) without having to depend upon
| concentrated and contested oil supplies.
|
| More than energy efficiency its volumetric efficiency that's
| the issue. At the moment (to the best of my knowledge) kg of
| capturing materials capture tens of grams of CO2. Pulling it
| from air is not that energy intensive but finding materials
| that can actually filter out CO2 from that air is difficult. If
| breakthroughs are made in this area it will have industrial
| applications. Then it won't be just sequestering.
|
| Of course the easier solution is to plant more trees and
| grasses but they grow very slowly and require valuable land.
| Still this approach is feasible in some uncultivable lands.
| Crops like cottongrass[1] can grow even in tundra climate and
| can be valuable source of both technically imp carbon via
| cellulose and a means to capture CO2. We don't have to make a
| choice. We can do both simultaneously.
|
| [1]
| https://www.fs.usda.gov/database/feis/plants/graminoid/eriva...
| jmward01 wrote:
| I wonder what the economics could look like for using this
| with remote solar for production instead of considering it
| for global removal/sequestration. If you build a solar farm
| in a desert and use this to pull raw materials from the air
| to create something actually worth money, what levels of
| efficiency do you need to make that profitable? How close is
| something like that in reality?
| SquirrelOnFire wrote:
| Giant miscanthus can grow on land that's not viable for
| farming food (other than grazing grasses), has a lot of
| properties that ready it for becoming charcoal (high tonnage
| per acre, self drying, minimal inputs needed). Without a
| price for carbon, it's hard to make it work, though.
| amelius wrote:
| You might think it is silly to do this, but what if carbon
| emission trading makes this profitable?
| Retric wrote:
| That's like asking what happens if gravity reverses, the
| answer is irrelevant because the situation is not going to
| happen.
| Retric wrote:
| When a question assumes as part of its premise that
| something is a good idea, it is no longer a meaningful
| question.
|
| https://en.wikipedia.org/wiki/Begging_the_question
| abraae wrote:
| Removing CO2 from the air is a pipe dream for several obvious
| reasons.
|
| Firstly, it will always be more difficult and energy-intensive
| to extract CO2 than to just stop putting it into the atmosphere
| in the first place. Yet the world is nowhere near agreeing any
| meaningful framework on reducing emissions, and the party in
| power in the largest democracy in the world is in denial that a
| problem even exists.
|
| But mainly, if there was an effective means of CO2 removal, who
| will be in charge of the dials, and who will set the targets?
|
| Atmospheric CO2 is now 50% higher than when I was born. Will we
| go back to the levels as at the 60s, or perhaps the beginning
| of the industrial revolution? Obviously that is unfavorable to
| the frozen regions that are now thawing - like Russia (and
| Greenland), who benefit from climate change.
| kbrkbr wrote:
| > Removing CO2 from the air is a pipe dream for several
| obvious reasons.
|
| For me at least both your arguments are not obvious.
|
| There are a lot of things that are harder to put in the
| atmosphere than to remove them. Stones for example.
|
| The second one is less of an argument, but rather a question.
| Why not the UN, the US, China, or Europe?
| orbital_laser wrote:
| Stop writing confident rhetorical takes on about which you
| know nothing.
| abraae wrote:
| You really created an account to post this?
| imtringued wrote:
| Not just that, he burned a cool username for it. Shame on
| him!
| tim333 wrote:
| It's not practical now but maybe in a more enlightened (and
| warm) future it may be?
| https://en.wikipedia.org/wiki/Ocean_fertilization could be
| cheap for example.
| rayiner wrote:
| > The only solution we have is put less in the air in the first
| place
|
| That's not a solution either, because the developing world is
| not going to stop increasing their CO2 output until they fully
| industrialize. They're just not. Feel free to seek reductions
| where you can, but don't think of it as a solution because it's
| not.
|
| The technical problems with CO2 capture are far more solvable
| than the sociological problems with net zero emissions.
| dalyons wrote:
| I think they are, but more by accident. They're going to
| industrialize with renewables, batteries, EVs and electric
| everything. It's inevitable due to economics
| rayiner wrote:
| They will increase emissions more slowly than European
| countries did at the same phase in their development, but
| emissions will still go up a ton compared to now. China's
| CO2 emissions per capita is now almost double that of
| France. India has gone from 0.5 tons/person in 1980 to over
| 2 tons/person today. They're building some renewables, but
| they're also building a ton of coal and gas. The EU retired
| 11 GW of coal in 2024, while China built 30GW and India
| built another 6 GW.
|
| It's not just economics, it's logistics. Countries like
| Bangladesh don't have the space to build wind and solar,
| and they don't have the sophistication to manage long
| distance grids with batteries, EVs, etc. That's why they
| keep building more coal. They're not stupid, there is just
| are practical concerns these countries confront that don't
| exist in countries that have more central organizational
| capacity.
|
| And the math just sucks. Say countries like India
| industrialize with a high percentage of renewables, etc.,
| so they end up with developed economies at just double the
| current CO2 output of India (4 tons/capita). That would
| mean that the growth in CO2 output from the subcontinent
| alone (India+Pakistan+Bangladesh) would exceed the current
| CO2 output of _the entire EU_.
| rangestransform wrote:
| China couldn't jump past the fossil fuel stage of
| technology development, but now its technology
| development and gigantic manufacturing capacity allows it
| to help poorer nations fully bypass that stage.
|
| I think it's entirely possible that giving first world
| money to poor nations to buy Chinese solar and batteries
| is a more cost effective solution to carbon emissions
| than paying western skilled labour wages to decarbonize
| energy production in the west.
|
| Of course, I'm sure you'll have tremendous success
| convincing "candy for dinner" American voters to pay
| third worlders to spend in China
| crucialfelix wrote:
| Developing world generally has a lot more sunlight, and now
| very cheap solar energy.
| rayiner wrote:
| It's not cheaper when you factor in the batteries, the need
| for sophisticated electric grids, etc. China and India
| continue to build huge amounts of coal power. It's not
| because they're too stupid to buy the cheaper option.
| thechao wrote:
| I'm going to have to disagree in a (hopefully) nuanced way.
| First, I just ran an end-to-end continent scale simulation of
| CO2 sequestration for the US, as is. To put it bluntly: there's
| no way outside of magical pocket sized fusion that will make
| this work. If you add full ground transportation abatement;
| full power abatement; and, then, use dedicated thermal sources,
| then the final cost is ~1 trillion a year. And, that's after
| all the positive upsides to the economy. There's a bunch of
| "almost unlimited upside" to be had from not having to move
| Miami, Houston, etc., but it's too complicated to model.
| However, just the healthcare implication upsides are roughly
| parity, disaster included.
|
| But! Notice that abatement doesn't get us to 0. It merely
| _slows_ the process. The remainder absolutely needs ACC. The
| output stream needs to be dirt cheap, the thermals need to be
| 100degC and not 900degC. Those sorts of things would bring ACC
| down to "hundreds of billions" rather than a trillion.
| testing22321 wrote:
| Zoidberg is always worth quoting.
|
| "Why not both?"
| steeve wrote:
| Thank you
| standeven wrote:
| This. The fossil fuel industry continues to overflow the tub
| with CO2, but instead of turning off the tap, we keep trying to
| invent a better sponge.
|
| We need carbon taxes, tariffs on high-emitting countries and
| products, and support for adopting clean energy, clean
| transportation, and clean everything else. Lobbying and
| misinformation has made these actual solutions politically
| impossible to implement though, so we continue to waste
| resources on sponges.
| beloch wrote:
| "The Wizard and the Prophet" by Charles C Mann sets up an
| interesting duality that I think more people should be aware
| of.
|
| Mann describes "Prophets" as people who see a problem and then
| try to prod people to change their behaviour in order to avoid
| it. e.g. Thomas Malthus observed that exponential population
| growth had humanity on track to experience severe famine,
| conflict, etc. that would violently and savagely bring our
| numbers back within the carrying capacity of the Earth.
| Multiple people have made predictions about when humanity would
| reach the brink at numerous points in the years since Malthus,
| but were always wrong about _when_ the Malthusian trap would
| finally spring...
|
| ...because of "Wizards". Wizards are people who set about
| solving problems with tech. Advances like the use of
| fertilizer, first bat guano and then the Haber-Bosch process,
| followed by scientific crop breeding have effectively raised
| the carrying capacity of the Earth so much that, despite our
| exponentially ballooning numbers, there are far more calories
| per person available now than in Malthus' day.
|
| Prophets are valuable for their ability to observe and raise
| awareness about problems. The Earth does have an ultimate
| carrying capacity too, which we should keep in mind even if we
| don't know what it is. However, the track record undeniably
| favours the Wizards. They get things done. Prophets _hate_
| this, because it makes it look like they were wrong. They weren
| 't wrong. They were just too focused on an approach to the
| problem that rarely works.
|
| The modern environmentalist movement is dominated by prophets.
| So much so, that wizards are often portrayed as the enemy.
| History has shown that this is wrong-headed. We should value
| prophets for what they do, but ignore them when they tell us
| not to fund the wizards.
| vdupras wrote:
| Wizards invented guns, good for them, but now the order is
| tall: they need to figure out how to undo the effect of their
| bullets.
| LasEspuelas wrote:
| This seems like the actual work of the article:
| https://pubs.acs.org/doi/10.1021/acs.est.5c13908
|
| And the superbase is 1,5,7-triazabicyclo [4.3.0] non-6-ene
|
| It is an anime based technology. Other amines in water-based
| solutions also get regenerated at about <200C. It is great to
| find new molecules to do this work but as I usual, these
| marketing articles sensationalize the actual work.
| lemoncucumber wrote:
| I would've expected the research to be coming out of Japan if
| it's an anime based technology ;)
| spants wrote:
| how about trees? just a thought.
| paseante wrote:
| That's the first thing I thought when I read the title. Hey we
| have already efficient systems for eliminating CO2 from the
| athmosphere: trees!. The joke tells itself.
|
| It seems like we have not yet done the full circle, but we are
| close.
| ReptileMan wrote:
| Just use lye to baking soda. You could in theory make an
| efficient roundtrip.
|
| Anyway - CO2 in the atmosphere is here to stay. Much more
| "realistic" approach is to decarbonize the ocean and let the
| ocean absorb the atmospheric CO2.
| zeristor wrote:
| One thought I had was to go a very cold place and freeze CO2 out
| of the air, about -80degC.
|
| There's the katabatic winds off of the glaciers in Greenland and
| Antarctica, which could help things go through.
|
| But I soon realised that CO2 is so potent, that it's so such a
| small proportion of the air that not much would be taken out.
|
| There's some renewable storage systems that liquify air, that
| could remove CO2 but they don't mention it;,but air liquification
| doesn't seem to be growing fast as an option.
|
| The other one from mere A-level chemistry is buffer solutions and
| using chemical reactions in the Oceans, apart from iron seeding
| for life, but a chemical that precipitate an insoluble carbonate.
| Not ideal raining down precipitates, or using the Ocean as a test
| tube.
| DivingForGold wrote:
| Tired of EU "nag screens" ?
|
| https://archive.ph/SjcLx
| moktonar wrote:
| I read somewhere that electrolysis of marine water could emit
| enough oxygen, while also harvesting hydrogen, to counter CO2
| emissions, but I can't find the source, has anyone heard of it
| before or am I filling the gaps of my memory with generated
| garbage?
| cramcgrab wrote:
| Trees!
| m0llusk wrote:
| It seems like the focus should be on capturing carbon dioxide
| from the oceans. Carbon dioxide in the atmosphere is extremely
| diffuse, but the oceans absorb it in large quantities and as a
| result it becomes much more dense which makes capture
| fundamentally more efficient.
| blacksqr wrote:
| The best carbon capture device is the ocean, and for the last 10
| years or so huge amounts of free-floating sargassum seaweed have
| grown in warm ocean waters around the world. Nobody is certain
| why the sargassum has appeared in such volume lately, but it's
| plausible to speculate that increased CO2 in ocean water plays a
| role. As far as I can see the only remotely efficient way to
| sequester carbon at scale is to leverage the ocean by gathering
| the seaweed and dumping it on marginal or desert land, both to
| trap the carbon and fertilize the soil, thus promoting additional
| carbon-binding plant growth.
| conductr wrote:
| As a layman on this topic, but assuming the gathering requires
| fossil fuel and probably lots of it given the scale, is it
| feasible to do the gathering in a net negative carbon way?
|
| I feel like anything I hear about that teases net negative
| sequestration at scale eventually falls apart or is found to be
| akin to a perpetual energy machine that eventually is debunked.
| ethbr1 wrote:
| If only there were a carbon-free method to move vessels
| across the water.
| tczMUFlmoNk wrote:
| Maybe we could put a wind turbine on the boat, generate
| electrical power, and use that to power an onboard motor!
| number6 wrote:
| On good days you could use a solar collector to boil
| water and generate electricity with it
| zahlman wrote:
| > leverage the ocean by gathering the seaweed and dumping it on
| marginal or desert land
|
| Why would it gather more CO2 over there than it does where it
| already is?
| jayd16 wrote:
| They're suggesting to harvest it and sequester it elsewhere,
| making room for more to grow.
| MetaWhirledPeas wrote:
| Presumably relocating it makes room for more?
| ethbr1 wrote:
| > _for the last 10 years or so huge amounts of free-floating
| sargassum seaweed have grown in warm ocean waters around the
| world_
|
| For those curious about numbers for 2025, a couple links:
| https://optics.marine.usf.edu/projects/SaWS/pdf/Sargassum_ou...
| https://abcnews.go.com/International/scientists-concerned-re...
|
| > _Nobody is certain why the sargassum has appeared in such
| volume lately_
|
| For the record 2025 volumes specifically, the ABC article notes
| that sudden phosphorus flushes as a result of multi-year
| drought-hit watersheds finally being flushed out likely
| contributed. Ocean ecology at scale is usually highly
| correlated with nutrient density.
| softwaredoug wrote:
| Alkalinity enhancement of oceans (so it absorbs more carbon) is
| one carbon capture mechanism.
|
| https://oceanvisions.org/ocean-alkalinity-enhancement/
|
| But in general carbon absorption by oceans leads to
| acidification and habitat destruction.
| constantcrying wrote:
| People need to keep in mind how rare CO2 is in the atmosphere. It
| currently is at around 420 ppm and was at around 100 ppm less in
| the 60s. CO2 is a miniscule part of the atmosphere, which is why
| large _relative_ changes are caused by human activity.
|
| To remove 10ppm of atmospheric CO2 from the atmosphere (which
| would do nothing to sustainably lower CO2 in the atmosphere)
| would require processing 10ppm of the _entire_ atmosphere. That
| is one in 100.000 parts of the atmosphere. The entire atmosphere
| is around 5x10^18 kg, so we need to process 5x10^13 kg of air.
| Which is 50 million million (no typo) kilos of air.
|
| The industrial task of doing this unfathomably large and by
| itself would have no long term Impact.
|
| Human fabricated carbon capture from ambient air is a complete
| fools errand only promoted by the scientific illiterate or those
| who benefit from scientific illiteracy. You can essentially just
| look at the first graph on wikipedia and see that it is never
| going to work:
| https://en.wikipedia.org/wiki/Carbon_dioxide_in_the_atmosphe...
| tasty_freeze wrote:
| The article doesn't mention the energy costs directly. The fluid
| is good for at most 100 cycles, probably less, to release the
| captured CO2 requires heating the fluid to 70C, and then you
| still have the problem of disposing the CO2 in some way. All cost
| energy.
|
| A given locale has some metric, based on local generation
| sources, for grams of CO2 emitted per kWh or whatever. How much
| CO2 is released to capture 1 gram of CO2? If it is close to a
| gram or more, this is not worth considering. Maybe one day zero-
| carbon energy sources become so inexpensive we could contemplate
| wide-scale CO2 capture, but we aren't anywhere close yet.
| -warren wrote:
| Sounds like this would be great on a long haul space mission
| where carbon capture is small scale, but very important!
| namuol wrote:
| Keep it in the ground.
| WalterBright wrote:
| Never mind the CO2 released in making the ingredients and
| recycling them.
|
| Just plant a tree, harvest it to make lumber.
|
| The article's method might be useful in a submarine or
| spacecraft.
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