The best carbon capture device is the ocean, and for the last 10 years or so huge amounts of free-floating sargassum seaweed have grown in warm ocean waters around the world. Nobody is certain why the sargassum has appeared in such volume lately, but it's plausible to speculate that increased CO2 in ocean water plays a role. As far as I can see the only remotely efficient way to sequester carbon at scale is to leverage the ocean by gathering the seaweed and dumping it on marginal or desert land, both to trap the carbon and fertilize the soil, thus promoting additional carbon-binding plant growth.