I'll echo this - The technological developments we need to sequester gigatonnes of carbon at the level that it would make a difference already exists and are in common use, at scale, today. In my assessment most work on novel carbon capture technology is really working out how to make something that's profitable. I'm not confident it's an area of research likely to bear fruit although I also don't want to sound like I'm putting down folks who are doing much more than me here armchair judging.
Aside from growing then burying cellulose or cooking it off into carbon, you could also pyrolize it into a liquid form via a self-feeding process if your preferred form of sequestration is to pump it back underground i.e. into previous extraction fields.
Direct air capture is something that makes me doubly wary - Aside from the carbon-density-in-air issue, return-on-energy-invested is a key metric I don't see enough emerging encouraging information about. Incorporating the acres of wind, solar, or hydro required to power a DAC solution, the usual land-use objection to a forestry-based carbon removal approach would seem to evaporate pretty quick.
Aside from growing then burying cellulose or cooking it off into carbon, you could also pyrolize it into a liquid form via a self-feeding process if your preferred form of sequestration is to pump it back underground i.e. into previous extraction fields.
Direct air capture is something that makes me doubly wary - Aside from the carbon-density-in-air issue, return-on-energy-invested is a key metric I don't see enough emerging encouraging information about. Incorporating the acres of wind, solar, or hydro required to power a DAC solution, the usual land-use objection to a forestry-based carbon removal approach would seem to evaporate pretty quick.