Matt Farrell delves into what carbon capture utilization storage (CCUS) can and can't do for reducing greenhouse gases. There are several big issues. First, doing CCUS at a scale that would make a difference will take a lot of time and money, so as a species, we would need to commit to retrofitting carbon-emitting energy plants. Those plants need to run until suitable replacements are built, but they are responsible for the overwhelming amount of CO2 emissions.
The other big issue is what to do with it once it's captured. Some oil companies want to use it for procedures similar to fracking, with all the attendant problems of that. Storing it underground has been proposed, but there are places where that is not feasible. One promising option is to use it in cement production, thus trapping it in buildings, roads, and other useful structures.
To get a sensse of just how much carbon needs to be captured, it's the equivalent of almost 140,000 great pyramids, according to Strelka:
The 138,462 pyramids calculated by our physicist friend presume a volume composed entirely of biomass. If constructed, each Giza-like pyramid would occupy thirteen acres (52,900 m²) and rise to a height of 455 feet (138.8 m). Absent any supporting infrastructure, these 138,462 pyramids would cover 2,839 mi² (7,353 km²), an area almost half the size of Beijing, three times the size of Moscow or Tokyo, or nearly ten times the size of New York City. The amount of biomass needed to construct this scheme would require wholesale shifts in existing land use practices, and we can imagine vast plantations of bamboo and other fast-growing woody plants, which might then be harvested by seasonal armies of government workers. Perhaps these harvested materials would be ground down into fiber for use as a modular building product. Cellulose megaliths might be stacked one upon another.