3 ms·

So first it’s 1.68 trillions of dollars per year every year with political battles over who should be paying for this. And that’s just to get to net 0 for 1 yea

So first it’s 1.68 trillions of dollars per year every year with political battles over who should be paying for this. And that’s just to get to net 0 for 1 year with a technology we don’t know how to actually scale to do 40Gton a year. That 1.68T number (insanely optimistic btw because 4c/kwh is quite cheap and it’s probably closer to 3-5x more expensive in practice), is just electricity. People to build these factories need salaries. There are significant construction costs. And then there’s the 40GTon of captured co2 we’d need to sequester - figuring out where to store it is a huge problem. And remember we need to repeat this process each year ongoing to keep up - forget about all the co2 already in the air. Oh and these tend to be chemical reactions so you’re also going to have to be shipping large scale of consumables around to perform the sequestration process. Sequestration is a long long long way off from being practical if it ever even gets there and you’ve wildly underestimated the cost and complexity I think.

lumost 3y ago
Sequestration via pulverized stone will yield various precipitates into the soil, in many cases - the byproducts should be tunable to enrich the soil. I’m less concerned about total cost, olivine weathering proposals generally sit at $50 per ton delivered and applied where it’s needed. Which is 1/3rd the price of the electricity I estimated. That gets us into the realm of 500 billion per year. Less than the US’s defense budget. If more economic efforts materialize - perhaps we’d get to 100-300 billion per year at which point joint funding becomes obvious. Still great to do the other things, but let’s not ignore a technology which is promising and cheap.