Hacker News Reader

Comment by wiz21c | Hacker News Reader

website: "With 3 tons of basalt application you can capture up to 1 ton of CO2. Our software optimizes both for crop yield and carbon capture — making your land as productive as possible while you earn revenue from carbon removal."

Should I read: 1 CO2 ton effectively captured after discounting CO2 emitted for basalt extraction and dispersion ?

View on HN

I am also curious how much carbon is released to extract and spread that 3 tons. I'm guessing it's still a net carbon-negative, but that's still a lot of material to be moving around.

Yikes, that is a terrible ratio. A single emission source is considered an "insignificant" CO2 emitter if it emits less than 100,000 metric tons of CO2 per year. People don't realize just how much CO2 is being emitted; it's staggering. This seems way worse than (albeit not an alternative to) planting a tree.

The issue is that trees release that CO2 back into the atmosphere when they eventually die and decompose. Only expanding the coverage of living forest actually captures carbon, and it's a one time thing. As a reference, an acre of forest in Maine stores about 400 tons of CO2, putting away about 8 tons per year until it reaches maturity. To expand forest coverage you're either taking land that was previously deforested for some reason (for example agriculture), in which case you're competing with that alternative land use, or you're planting trees in an area that never had forest, almost certainly because the location is not naturally conducive to forest, meaning you need to expend substantial resources to make it (possibly literally) take root. You can get more out of it by burying trees after they die such that they can't decompose, but this is a substantial labor investment.

With weathering, the carbon is permanently locked away and as long as there is more rock to weather you can keep capturing more and more carbon. We already produce billions of tons of waste rock each year as a byproduct of mining. The bottleneck is entirely the extraction of desired resources from that rock. If we didn't care about that, it's really easy to just blow up massive quantities of rock to dramatically increase the exposed surface area.

Only basalt absorption judging by the wording, and that sounds optimist (unsurprising for marketing material):

"One tonne of basalt captures 0.153–0.165 tonne CO2, depending on infiltration rate (400–1200 mm/a), reactive surface area (3.7–15 m2/g) and CO2 partial pressure (41.1–3000 Pa). When the infiltration rate is high (1200 mm/a), the CO2 capture capacity of basalt is exhausted after 9.5–11.4 years." [1]

[1] https://link.springer.com/article/10.1007/s12665-022-10320-0

It's gross not net. The way they minimize is that they use basalt waste (so they don't dig for it, it's been dug for) and they deliver as local as they can so there's hopefully low transport costs. I don't know if moving basalt waste is something mines already do and if they specifically count that.

I suppose one could argue that by reducing the cost of getting that waste away, they're effectively incentivizing mining. You'd need a more sophisticated model to see if this will work.

This probably makes more sense in a context where mining and transport was done carbon neutrally. Similar to how switching to an EV doesn't automatically lower your CO2 bill if the electricity you use is dirty but it allows for decentralized improvements (i.e. renewable energy) that roll out without the individual having to do anything.

No. There's no way that this is carbon negative.

Lithos is almost certainly one of the many scam CO2 projects.

no, it sounds to me that it requires 3 tons of basalt to capture 1 ton of CO2. it does not read like it is making any claims beyond that. it reads to me as if you're putting words into it on your own.

Reply on news.ycombinator.com