summary of national academies of science report on NETs -

solutions to sequester carbon from the atmosphere are as follows:
1) coastal blue carbon
2) afforestation / reforestation
3) forest management
4) agricultural soil adjustments / management
5) direct air capture
6) carbon mineralization

The latter two here are currently not cost-effective at scale (direct air capture is in the ~$600/ton of carbon, whereas more likely what we need is something between $50-100 (though I don't fully understand the economics yet)), and carbon mineralization we don't really understand.

Furthermore, the first four here are severely limited beyond their theoretical limit of ~10 gt/yr globally due to land use constraints (land needs to be used for food, etc.). By severely I mean potentially a factor of 2 to an order of magnitude