Enhanced Rock Weathering was discussed recently[1], and that is cost effective at something like $100/ton. I don’t think there is any question about whether it’

Enhanced Rock Weathering was discussed recently[1], and that is cost effective at something like $100/ton. I don’t think there is any question about whether it’s thermodynamically possible (trees do it, as you say), it’s more whether it’s economically possible; without a carbon tax there is no real incentive for most producers to offset. (If we are relying on demand from “ethical consumers” I don’t think we are going to shift things very far.) 1: https://www.theguardian.com/environment/2020/jul/08/spreading-rock-dust-on-fields-could-remove-vast-amounts-of-co2-from-air https://www.theguardian.com/environment/2020/jul/08/spreadin...