The storage part is a big issue with current plans for CCS and DAC. If they end up turning around and repackaging the CO2 into something that can be released again, it’s only better than pumping out new petroleum and not a true reduction.

But the title is a bit wrong. It should be “Pulling CO2 out of the air alone won’t stop climate change”. Even if we dropped the CO2 level to preexisting levels (280ppm or even lower) there are still some feedbacks already in play that wouldn’t suddenly stop their contribution. It would be far better than continuing to add to CO2 for sure, but there is still going to be some climate change and adaptation needs regardless of how well we act. And of course, we are not acting very well.

If only we could use massive floating solar arrays anchored over the Mariana Trench, and use that power to create carbon fibre from atmospheric CO2. Some could be used in industry, but let’s scale that up until we are creating solid spheres of carbon 1-2m in diameter and dropping those into that subduction trench. It will take some time, but most ought to be pulled down into the crust via subduction, and return carbon to the mantle where it ought to be locked away for several hundred million years.

Keep doing that until we have gotten things back down to under 200ppm.