Hemp. Nature provides a way to do many things that technology can't do efficiently. Hemp will capture carbon and store 80% in the roots. We would need 5 billion acres of hemp production to remove double our current emissions, I did the math a year ago. That would only be achievable with floating greenhouses, as far as I can figure, but if we hit net zero, then hemp looks much more doable in terms of a long term solution.

Edit: Also marijuana, and we can still use both plants the way we currently do, just store the roots in drums and fill up Yucca Mountain, since we aren't storing nuclear waste there.