>Their model also incorporated the emissions costs of mining and then spreading this powdered rock over fields.
Of course, there's always a chance of errors in both how they estimated these emissions and how they estimated the amount of CO2 that will be removed.
Sounds promising though.
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_...
> A new study estimates that the low-tech method could capture almost half the carbon the UK needs to meet its climate goals
> [...]could capture 45% percent of the carbon dioxide required to help the UK meet its 2050 net-zero targets
Edit: I hadn't read the article. That indeed seems to be the goal. On that basis, yes the math appears wrong.
The goal is to find a different reality than that one.
If this works then doing it more is clearly possible. Maybe not politically or economically viable in the current circumstances but certainly possible. If weathering fine gravel/dust is the mechanism there’s an awful lot of coastal land with relatively active currents in the UK and elsewhere to dump it.
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.
There are lots of opportunities for harm, but plenty of material that would be beneficial, particularly for crops that like higher pH.
Olivine, e g., often has excess nickel, which you then would not use on farmland. You might dump that on beaches, instead. The main thing is to move a lot of it. You would prefer to use renewable electric to crush it, but the main thing is to get started.
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.
*(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).
We really need both, and as much of both as possible as soon as possible.
Putting gigatons of co2 to the atmosphere _is_ natural?
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.
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.
Plant a tree.
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.)
- does it have any impact on, you know, the farms you're putting it on?
These two questions probably already have an answer: we already grow plants, vegetables, fruit trees on basaltic soils (soils formed by the erosion of basaltic rocks). Some European countries have almost only them, like Iceland, Albania, Montenegro. Usually the crops are excellent, and benefits directly from this natural fertilizer e.g. some Italian wines. These rocks also help to capture water in arid regions, btw. We are also plenty of real world experiments of adding these substances to other ecosystems: every basaltic volcanic eruption distribute a dust cloud around the vent, usually in an area of hundreds km^2, influencing the environment.
There are many, many examples of miracle technologies that have huge effects for the resources expended on them: antibiotics, vaccines, printing, writing, mathematics, the transistor.
My concern with all these approaches is the nickel content of olivine, which can be several tenths of a percent.
I'm way more concerned with the side effects of the process as others have mentioned. Maybe not heavy metals, but soil PH, and other poisons.
Still, if it's this easy we really need to be doing this.
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.
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-crushin...
[2] https://www.wren.co/projects/mineral-weathering-in-scotland
re phytoplankton/marine life: I guess basalt particles will sink. But if sinking is slow the top layer will get murky absorbing the light.
Rock dust doesn't sound very healthy. People and animals next to the farm will breathe it when the weather is dry.
"...which involves modifying soils with crushed silicate rocks, such as basalt."
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.
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.
"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."
"...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."
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?
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!
It might be low-tech, but it’s not really a regenerative approach.
Spreading rock dust on fields could remove vast amounts of CO2 from air (2020; 109 comments) - 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
It’s also a way to move away from chemical fertilizer made from mined minerals and natural gas
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.
