[leoedin]

This definitely seems the most feasible. Sure, plants aren't particularly efficient, but they're also self-reproducing and self-maintaining, which is a huge bonus.

One interesting approach with plants is to pyrolise them to make biochar - essentially turn them to charcoal. You get a bit of hydrocarbon gas out of them, which you can sell to pay the bills (this is the biggest problem with any carbon capture - there's basically no way to pay the bills), and then you bury the pure carbon that you're left with.

I did a bit of research on this a while back and wrote up the calculations here:https://concretecuts.xyz/articles/biochar

Essentially we'd need to devote quite large amounts of land towards this if we wanted to compensate for our current emissions - something like 66% of the world's forests would need to be periodically cut down, with around 1% cut down and pyrolised each year.

You could probably get some easy wins with existing wood and crop waste - by my estimate we could capture 3% of global emissions just by pyrolising Europe's existing biofuel feedstocks.