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Spreading rock dust on farms as a climate solution
- black_13 4y ago
- spenrose 4y agoPaper from researchers: https://www.nature.com/articles/s43247-022-00436-3 https://www.nature.com/articles/s43247-022-00436-3 "Using life-cycle assessment modelling of potential supply chain impacts for twelve nations undertaking Enhanced Rock Weathering deployment to deliver up to net 2 Gt CO2 yr−1 CDR, we find that rock grinding rather than mining exerts the dominant influence on environmental impacts. This finding holds under both a business-as-usual and clean energy mix scenario to 2050 but transitioning to undertaking Enhanced Rock Weathering in the future with low carbon energy systems improves the sustainability of the Enhanced Rock Weathering supply chain. We find that Enhanced Rock Weathering is competitive with other large-scale Carbon Dioxide Removal strategies in terms of energy and water demands."
- MrDunham 4y agoI found these parts also interesting from that study: "...it is competitive in terms of sustainability. It has half the energy demand of DACS, avoids land-use competition of other land-based technologies (Bioenergy with Carbon Capture and Storage, afforestation/reforestation/biochar), and has a 10–100-fold lower water demand than these other CDR strategies."
- faleidel 4y agoA similar idea using olivine: https://www.technologyreview.com/2020/06/22/1004218/how-green-sand-could-capture-billions-of-tons-of-carbon-dioxide/ https://www.technologyreview.com/2020/06/22/1004218/how-gree...
- bradrn 4y agoThis is pretty much exactly the same idea: the paper referenced by the article mentions basalt specifically, which has olivine as a major constituent.
- xingyzt 4y agoNewer studies have put doubt to olivine's effectiveness: https://www.technologyreview.com/2022/03/30/1048434/why-using-the-oceans-to-suck-up-co2-might-not-be-as-easy-as-hoped/ https://www.technologyreview.com/2022/03/30/1048434/why-usin...
- pfdietz 4y agoThat was about putting olivine in seawater, not spreading it on soil. My concern with all these approaches is the nickel content of olivine, which can be several tenths of a percent.
- ncmncm 4y agoYes, you would favor using the low-nickel supply on farmland. I wonder if nickel in olivine would be harmful on beaches.
- heavyset_go 4y agoHere's a study that found that the olivine hypothesis might not work as expected: https://www.technologyreview.com/2022/03/30/1048434/why-using-the-oceans-to-suck-up-co2-might-not-be-as-easy-as-hoped/ https://www.technologyreview.com/2022/03/30/1048434/why-usin...
- penneyd 4y agoAny obvious downsides to this approach?
- sriku 4y agoMight need to be studied in different regions to determine whether there are any detrimental effects. It looks like it might alter the soil pH which could affect crops. Sounds promising though.
- ffhhj 4y agoDo rock minerals capture more oxigen than carbon?
- Maursault 4y agoAlso, inevitably running out of rocks.
- brokencode 4y agoCan somebody who knows about rocks weigh in here? I was under the assumption that pretty much the whole Earth crust was made of rocks, and that we’d run out of virtually any resource before we run out of rocks.
- jvanderbot 4y agoCrushing and distributing the required amount of rock seems challenging. Unless crushed rock is really produced enough by mining and is somehow really cheap to move (eg trains are coming back empty anyway)? It probably also adds another trip around the field for the combines? Still, if it's this easy we really need to be doing this.
- sriku 4y agoThe article does point out that the folks who studied this accounted for the carbon cost of doing that in estimating the capture benefits.
- ambrose2 4y agoYes, crushing and distributing is one of the main drawbacks. Too far from a mine and the net emissions are positive.
- puchatek 4y agoIt sounds like the potential of this technology is enormous so i would guess the distance would have to be very long before the emissions vaccine bet positive. Also there might be ways to combat that. Our fastest carbon sequestration method that scales are forests right now and they are slow to grow and need dedicated space. So let's build those EV combines or whatever it takes to keep rock dust net negative.
- travisporter 4y agoDiscussed by the late David mackay. http://www.withouthotair.com/c31/page_246.shtml http://www.withouthotair.com/c31/page_246.shtml
- eru 4y agoI really liked his book! I didn't know he died. That's such a shame.
- credit_guy 4y ago> by 2050, it could be removing up to 30 million tons of CO2 from the atmosphere each year, capturing almost half—45%—of the emissions the UK needs to vanquish from its atmosphere. The UK emits about 450 million tons of CO2. They are off by a factor of 6.75 https://en.m.wikipedia.org/wiki/Greenhouse_gas_emissions_by_the_United_Kingdom https://en.m.wikipedia.org/wiki/Greenhouse_gas_emissions_by_...
- throwawayboise 4y agoYou're assuming that the goal is getting to zero CO2 emission? There is no reality where that is possible. Edit: I hadn't read the article. That indeed seems to be the goal. On that basis, yes the math appears wrong.
- epgui 4y agoIt's difficult to think of any other reasonable goal that is not at least as "ambitious" as that one. That is, if one considers "trying to survive" an "ambitious" goal.
- thfuran 4y agoFrankly, we probably ought to hit net negative for some while to actually unwind the mess rather than settling for merely stopping accelerating the worsening but I agree with your assessment of the odds.
- steve76 4y ago
- beachy 4y agoAgree, and yet (assuming we reach that happy place) what happens next? Who decides how high to wind the global thermostat? Would countries who have benefited from increased temperatures (Russia perhaps) all fall in line and happily agree to go back to (say) pre-industrial revolution levels of CO2?
- rascul 4y agoIs this meant to be spread on cropland? I figure so because they say farmland and the (stock?) photo appears to be crops but I didn't see it specifically mentioned. What affects will it have on the crops?
- ggm 4y ago"It depends" some rock is net beneficial, can be both structural, physical-chemical effects on soil regarding clumping and water retention, and bio active (supporting beneficial micro-organisms, providing micro nutrients) Some phosphate rich rocks might be also known as.. fertiliser. Arsenous rocks would be a disaster. It's a huge issue in India with water table and ground contamination. Likewise lead, or salt (in the wider sense if it causes brackish ground water) although that's about deep wells. I have no idea if this is a serious risk for rockdust plans. For enough upside benefit downsides might have to be borne or mitigated.
- kuhewa 4y agoThe type of rock dust they are talking about is already commonly used as a soil amendment to add trace elements and minerals. That said it is possible I suppose that the optimal amount for carbon drawdown is greater than the optimal amount for crop health or yields
- rascul 4y agoBasalt is mentioned in the article. I know just a little bit about farming and growing things but I don't know anything about this rock stuff. But if it's good (or, perhaps, at least not bad) for the crops then it does seem like a possible good idea.
- kuhewa 4y agoBasalt rock dust is a pretty common amendment to add trace elements to soils especially in organic gardening
- tekstar 4y agoProbably a sort of crunchy effect, but hey it's high in minerals
- legitster 4y agoThere's an obvious path to a future where we can avoid the worst outcomes of climate change affordably using geoengineering. But the loudest detractors of these ideas are those who feel any path free of suffering or moralizing must be wrong. You can almost never get to a debate on the merits.
- version_five 4y agoI think you're right* It's easy to see who actually wants to address climate change, and who wants to use it as a lever to further a political agenda, by looking at support of different technological solutions, vs support for setting society and human progress back in some way as the only plausible solution. *(although I'm fuzzy on what can be included in geoengineering - this technology looks interesting and I'm a big fan of carbon capture, I don't support e.g. putting something in the atmosphere to reflect light into space or anything "unnatural" like that. But just removing CO2 from the atmosphere seems safe).
- ido 4y agoI think we should do everything we can (both reducing emissions and geoengineering) to fight climate change ASAP, but the problem is that a lot of very rich people (e.g. oil companies) are incentivized to not have people reduce emissions & will use the existence of technological solutions as an excuse to only do geoengineering. We really need both, and as much of both as possible as soon as possible.
- vkou 4y ago> use the existence of technological solutions as an excuse to only do geoengineering. Actually, they use the potential existence of technological solutions as an excuse to do nothing. The politicians they bought and pay for aren't keen on funding geo-engineering. And if they did, they'd do it out of general revenue, as opposed to a carbon tax.
- ido 4y ago
- paulcole 4y agoWhatever it takes so that nobody in America has to make any substantive changes in their way of life.
- moron4hire 4y agoArticle is about the UK, but regardless, if it can be done, why not? You got some kind of neocatholic guilt going on? "Climate change mitigation doesn't matter if it doesn't come with a heaping side of suffering".
- paulcole 4y agoIt can’t be done — that’s the problem. Anybody who thinks the “answer” to climate change is anything but sweeping changes to the Western way of living is sadly mistaken. Either it happens through choice before things get too awful or by necessity when things get more awful than anyone alive today is willing to imagine. You can stick your head in the sand and think “boy this rock dust will definitely do the trick…” or you can come to terms with the truth. Climate change is going to deliver suffering whether we mitigate it or not. I have no guilt. I don’t have kids, I live in a small apartment. I don’t eat meat. I don’t drive. I don’t go on airplanes. Even that isn’t enough, but I sleep fine.
- mrfusion 4y agoSo why would rocks do this but not the soil that’s already on the ground there? Isn’t it basically the same stuff?
- barry-cotter 4y agoThe surface area of a mountain and the surface area of that mountain ground into fine gravel are very different. The same thing happens to the surface area in both cases, yes.
- LarsAlereon 4y agoThe rock that's in the soil may not be the correct type, or it may have already reacted, or it may be in chunks that are too large to dissolve on human-relevant timescales. The idea is that you want ultramafic rocks, which are low in non-reactive Silica but rich in Magnesium and Iron oxides. These oxides absorb CO2 from the atmosphere to form carbonates and bicarbonates, sequestering it for geologic time. However, since reactions can only occur on the surface and when the minerals are dissolved, a big pile of mine spoil or river-sized rocks buried in the ground aren't doing much to absorb CO2. But if we grind it up into rock powder and spread it over fields, or crush it up into sand and dump it on beaches to let the ocean do much of the work of grinding and distributing it, the vastly increased surface area means a significant amount of CO2 can be absorbed in a human lifetime. There can also be pros or cons associated with the minerals in the rocks. For example, you don't want to spread rock containing heavy metals on fields where you grow food. On the other hand, rocks rich in Potassium are a beneficial fertilizer, and Iron-bearing rock spread in the ocean can encourage the growth of phytoplankton that further absorb CO2.
- opportune 4y agoSoil with CO2-absorbing minerals that’s already exposed to the air would already have absorbed the CO2. It’s like saying why plant trees to remove carbon from the atmosphere when we already have trees.
- pfdietz 4y agoOlivine is a particularly easily weather silicate, because the silicon atoms are in isolated SiO4(-4) tetrahedra. In most other silicates, the silica tetraheda are linked covalently by shared oxygen atoms and weather much more slowly.
- jeremygaither 4y agoThere is probably a lot of leftover rock from extracting everyday things like aluminum, as well as rare earth elements, which electronics manufacturing needs for many components. If the generation of the stones that get crushed and used for dusting is an output of other essential mining projects, that could further offset the costs associated with generating rock dust. It could also potentially reduce the shortage of these rare earth minerals, and associated electronic components, by attracting more mining operations to operate in additional countries.
- ck2 4y agoIs "rock dust" proven, peer-reviewed and reproduced or is it some pet-theory of an academic or two? Because one thing I've noticed especially over the past two years of covid research, once some PhD seems to vapor-lock onto a single substance as a "miracle cure" they can write endlessly, breathlessly about it without mentioning a single downside or limitation.
- deleted 4y ago[deleted]
- wokwokwok 4y agoIt's hard not to be skeptical. If only there was a way to solve climate change with carbon capture that was low tech, easy to do, simple to understand, didn't pose any long term side effects and pretty cheap to do. Oh, and it can solve all the CO2 emissions you could ever want, so you know, you don't even have to make significant changes to your industry or way of life, because your emissions are pretty much flat out neutralized by this one simple thing. Sounds perfect right? Sounds like a silver bullet. ...but, silver bullets don't exist. So, I can guarantee it's not that simple. Maybe it's another useful tool to help tackle climate change, probably with more research as to how to actually works. ...but, I think anyone who's excited by this needs to calllllmmm the F down, because this idea has been around for quite a while, and no one is using it; so I suspect there are some things that still need to be figured out like: - do the benefits scale linearly, or is it a logarithmic curve (like most things)? - can you actually measure the amount of carbon captured to prove its working? - does it have any side effects on the ecosystem? - does it have any impact on, you know, the farms you're putting it on? - does their model (which is all they did, create a Matlab model) actually work in the real world? - how often do you have to do it for it to stay effective? It's complicated right. I mean, sounds promising... but this: > The simple act of sprinkling rock dust—an abundant byproduct of mining—on farmland could capture 45% percent of the carbon dioxide required to help the UK meet its 2050 net-zero targets. Is just idle wishing the problem away. It might. It might not. There's a model that suggests it might. I'm not convinced we should be sprinkling rock dust over the entire country quite yet.
- deleted 4y ago[deleted]
- WalterBright 4y ago> carbon capture that was low tech, easy to do, simple to understand, didn't pose any long term side effects and pretty cheap to do. Plant a tree.
- DoreenMichele 4y agoPshaw. Plant lots of trees. Even poorly educated, dirt poor people in underdeveloped countries can do it. (And are. See for example Pakistan, where they are planting 10 billion of them.)
- snidane 4y agoIf the rock dust captures so much CO2, what will the plants breathe?
- Thorrez 4y agoI think the idea is to get the CO2 levels to what they were 200 years ago. Plants breathed fine back then.
- snidane 4y agoWhy 200 years, an not say few million years? Used to be more CO2 and plants liked it better. Definitely grew higher back in those days. I suspect the answer 200 because it is assumed these days that CO2 produced since 1800 is all man made. Would like to genuinely know if that's the case or I'm missing something.
- Thorrez 4y agoThere was a rapid growth of CO2 that started around 200 years ago[1]. To get a time with the same levels as today, we have to go back 14 million years[2]. Back then the species alive were different than the species alive today, with one notable difference being humans. I don't think it's safe to assume we can take the CO2 levels back tens or hundreds of millions of years and assume the species alive today will handle that well. >I suspect the answer 200 because it is assumed these days that CO2 produced since 1800 is all man made. Would like to genuinely know if that's the case or I'm missing something. I came up with the number 200 because that's when the graph looked like it started going up. I definitely think it was caused by humans, but I didn't pick the number 200 based on some human historical event, but rather just by looking at the graph. Regardless of whether it was caused by humans, I think such a giant increase is disturbing and should be carefully analyzed for potential problems and dealt with if there are any. AFAIK, there was no CO2 increase as steep as this in history even going back hundreds of millions of years. [1] https://www.co2levels.org/ https://www.co2levels.org/ [2] https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_at...
- eru 4y agoCompare Gwern's proposal: https://www.gwern.net/CO2-Coin https://www.gwern.net/CO2-Coin
- datadata 4y agoAdding iron to the ocean to fertilize carbon sequester ING plankton is a interesting related approach: https://en.m.wikipedia.org/wiki/Iron_fertilization https://en.m.wikipedia.org/wiki/Iron_fertilization
- csnover 4y agoPrevious discussions on this approach: Spreading rock dust on fields could remove vast amounts of CO2 from air (2020; 109 comments) - https://news.ycombinator.com/item?id=23770718 https://news.ycombinator.com/item?id=23770718 Potential large-scale CO2 removal via enhanced rock weathering with croplands (2020; 90 comments) - https://news.ycombinator.com/item?id=23831411 https://news.ycombinator.com/item?id=23831411
- greeneggs 4y agoThe Future Forest Company spreads basalt on forestland for carbon sequestration [1]. Wren offers it as one of its carbon offsets [2]. However, it is currently the most expensive of their offset programs, per ton of carbon offset or removed, and significantly so. [1] https://www.fastcompany.com/90642582/this-company-is-crushing-rocks-and-fighting-climate-change https://www.fastcompany.com/90642582/this-company-is-crushin... [2] https://www.wren.co/projects/mineral-weathering-in-scotland https://www.wren.co/projects/mineral-weathering-in-scotland
- LarsAlereon 4y agoI think these mineral weathering programs may make the most sense when applied to the oceans, where they both sequester carbon and directly reduce the ocean acidification that is harming marine life. This is especially the case if wave action on beaches can reduce the amount of energy required to grind and distribute the rock. There also seems to be potential for additional capture by the iron content of the rock fertilizing the growth of phytoplankton in areas where that wouldn't be harmful to other marine life like coral. In areas with tropical coral adding Calcium both reduces acidity and helps shell building creatures.
- elmolino89 4y agoI am also leery about spreading mountains of silica dust on fields where it can be blown in the air and end up in our lungs eventually. re phytoplankton/marine life: I guess basalt particles will sink. But if sinking is slow the top layer will get murky absorbing the light.
- hosh 4y agoIsn’t that adding more dead dirt to dead dirt, rather than cultivating soil? How does rock dust encourage soil bacteria and fungi that symbiotically trade minerals for sugars with the plants? It might be low-tech, but it’s not really a regenerative approach.
- mjsweet 4y agoI am a worm farmer and soil amendments manufacturer. One of the most important ingredients that I feed my worms is blue metal and zeolite rock dust. Trace minerals including elements like boron and sulphur are important for cellular growth. The Australian continent where I am has extremely weathered soil, depleted of minerals. I hope to help put minerals and biology back into the soil.
- daodedickinson 4y agoI have rocks to sell if anyone's buying.
- blenderdt 4y agoWhat about silicosis? Rock dust doesn't sound very healthy. People and animals next to the farm will breathe it when the weather is dry.
- birdyrooster 4y agoSeems like your question answers itself. They will not use silicate minerals in their mix of rocks.
- blenderdt 4y agoFrom the paper: "...which involves modifying soils with crushed silicate rocks, such as basalt."
- gomijacogeo 4y ago1. How much additional energy does it take to pulverize the rock? 2. What about the effect the rock will have on soil pH? 3. What about leached salts and heavy metals?
- pfdietz 4y agoPulverizing rock requires little energy, if I recall correctly. This shouldn't be too surprising as one is breaking only a small fraction of the chemical bonds in the material.
- datavirtue 4y agoPulverizing rock is one of the most energy intensive activities on the planet.
- kmbfjr 4y agoThe limestone crusher a few miles from my home can’t use more than 400-500 kW/hr judging by the power lines. That is limestone, the article talks of basalt which seems would require more.
- ncmncm 4y agokW-hrs/hr, I presume you meant. Which is to say kW. Fortunately, rocks can be crushed with power from solar panels. There remains the issue of whether those panels are better used, just now, to displace natural gas burners emitting new CO2 than to crush rocks to absorb CO2. Or, equivalently, if NG-generated power used to crush rocks makes more CO2 than would then be absorbed by the rocks. In a near enough future, it won't matter, because the NG will all have been displaced already.
- deleted 4y ago[deleted]
- ncmncm 4y agoPeople used to do it with hammers.
- lifeplusplus 4y agoWhat happens after multiple layering / years after, won't you at some point remove rock layer to keep fertile soil
- dgan 4y ago> "assuming a baseline application rate of 40 t ha−1 yr−1 of basalt rock dust" I am sorry, what? 40 tonnes of basalt dust per hectar?? What's hilarious is that when you look up basalt dust on internet, merchants sell it in bags of 2kg, "to be applied 20 grammes/sq meter", while 40t/ha is 4kg per sq meter!
- osobo 4y agoSo, I did exactly that and got a recommendation of up to 10lb per 100 sq feet, which is over 4kg/9sq meter, off the first hit.
- verisimi 4y ago> The simple act of sprinkling rock dust—an abundant byproduct of mining—on farmland could capture 45% percent of the carbon dioxide required to help the UK meet its 2050 net-zero targets. Has this news been brought to me via the 'mining board'? Is it an attempt to get us to pay for their waste?! And won't rock dust degrade the soil quality?
- gonzo41 4y agoDepending on the size, it would be like putting a sand through the soil. Great for drainage.
- alfor 4y agoAlso consider that volcanic rock contain every elements necessary for plant and animal life. Volcanic rock dust + wood chips is a popular organic way to increase soil fertility. The rock supply all the elements and the wood chip the organic matter to feed the mycelium and other soil life. It’s also a way to move away from chemical fertilizer made from mined minerals and natural gas