Rock weathering for removing atmospheric CO2 (spreading rock dust on farmfields)

  • I was somewhat surprised to learn about this approach to removing carbon in the air. Rock weathering is the term used to describe rock dust (e.g. crushed basalt) being applied to farm fields.

    Why do this? The chemical reactions that degrade the rock particles lock CO2 into carbonates within months.

    The cost depends on local labour rates and varies from $80 per tonne in India to $160 in the US. This is in line with the $100-150 carbon price forecast by the World Bank for 2050.

    The best part - many farmers already add limestone dust to their land in order to reduce acidification. Adding other rock dust can improves fertility and crop yields.

    What do you think? Serious potential or is there something I'm missing?

  • Cool potential. The real question is whether (weather?) the economics make sense from the farmer's perspective. If so, I could see it gaining traction. There would need to be an efficient route for getting the carbon credit $ into the hands of the individual land owners