While these are interesting technologies, it's very difficult to see how they make sense economically. The cost/benefit ratio is invariably much worse than simply investing in emissions reductions.

If we have $X to invest in climate mitigation, it's always going to be better to spend it on technologies that reduce carbon emissions: replacing fossil-fuel power plants, electrification of transport, etc. To my knowledge there is no technology that removes a ton of carbon from the atmosphere that comes anywhere close to being competitive with what it costs to not emit that ton of carbon in the first place.

Of course, the day may come when all the easy carbon reductions have been made. If the climate is still not stabilising at that point, then we can start looking at all the climate engineering mega-projects.