Olivine is mined at $25/ton right now, which presumably takes capital requirements into account, so that's less of a concern from my POV.
The need for $900 billion to make this work (or even $300bln if the olivine price really drops as they predict) is the hard part. But then, the alternative is pretty much climate collapse, so it's still a bargain. Question is if people will realize that soon enough. But yeah, definitely not paid through jewelry. I'd imagine an actual emissions tax with teeth might help.
As for ecosystem impact, let's for now just look at a per-country amount. CR is 5M people, ~1.6tons of CO2/yr, so 8 megatons. With 800 miles of coastline, that's a lot of rocks - if they were only deposited on the beach. But it can be dumped in the water as well, if the currents are right. See e.g. https://projectvesta.org/science/#dflip-df_90/26/ (Not CR, but Europe, and basically says "pour it in the Channel")
I don't have the weathering rate, and the claim in their booklet (p. 32) actually doesn't make sense to me, so that's the big question for me as well. AIUI, this is the big unknown - they claim the old numbers don't apply, but they need to run a large-scale test to actually tell what the numbers would be.
I'm not, to be clear, saying "don't be skeptical". I'm merely saying as far as CO2 absorption ideas at scale go, this is one of the saner ones. It's not immediately unfeasible, and we should probably test it.
(As you can tell, I'm a fan of arguing on the Internet ;)
The need for $900 billion to make this work (or even $300bln if the olivine price really drops as they predict) is the hard part. But then, the alternative is pretty much climate collapse, so it's still a bargain. Question is if people will realize that soon enough. But yeah, definitely not paid through jewelry. I'd imagine an actual emissions tax with teeth might help.
As for ecosystem impact, let's for now just look at a per-country amount. CR is 5M people, ~1.6tons of CO2/yr, so 8 megatons. With 800 miles of coastline, that's a lot of rocks - if they were only deposited on the beach. But it can be dumped in the water as well, if the currents are right. See e.g. https://projectvesta.org/science/#dflip-df_90/26/ (Not CR, but Europe, and basically says "pour it in the Channel")
I don't have the weathering rate, and the claim in their booklet (p. 32) actually doesn't make sense to me, so that's the big question for me as well. AIUI, this is the big unknown - they claim the old numbers don't apply, but they need to run a large-scale test to actually tell what the numbers would be.
I'm not, to be clear, saying "don't be skeptical". I'm merely saying as far as CO2 absorption ideas at scale go, this is one of the saner ones. It's not immediately unfeasible, and we should probably test it.
(As you can tell, I'm a fan of arguing on the Internet ;)