This is an open scientific question, not an engineering problem, so there isn't a knowable answer right now on how long and what resources this might take. I ha

This is an open scientific question, not an engineering problem, so there isn't a knowable answer right now on how long and what resources this might take. I have a feeling that time would be the bottleneck. We also have several other routes for capturing and storing carbon from the atmosphere or ocean, other than by life forms, and it's likely that we would prefer those methods for all sorts of reasons. Ultimately, any sequestration is going to be far more expensive than just not emitting the carbon in the first place. And today, we have the technology to interchange 95% of our economy to be carbon free, without any reduction in standard of living, and in fact we would have a better standard of living because energy would be cheaper and we would have less disease from pollution. It's politics that is now the rate limiting step, not the tech. By the time we get that 95% of known solutions implemented, we will have lots of options for the remaining 5% And sequestration of carbon will certainly be required, starting around the 2050 era (according to an IPCC special report), but we should let that tech bake for 30 years before we start massive deployment so we can get the best options without too much lock in. Hopefully in 2030s there will be a robust carbon trading network which will cause larger scale deployment of carbon capture and sequestration, then we deploy gigaton scale in the 2050s