Humanity released ~36Giga-tons of carbon dioxide last year... capturing it will be a huge challenge- to reverse global warming you would need to capture 100's of billions of tons a year for quite a while. The immense power required to do this would need to be derived from non-carbon-emitting sources.

Lets say we magically could wave a wand and drop atmospheric carbon dioxide back to the levels it was in 1900 overnight... we would still be a warmer planet. The oceans have absorbed massive amounts of heat, and CO2... it will take a very long time for that to dissipate. We have less ice, so more of the incoming sunlight is absorbed. And as the tundra thaws from these higher temperatures it will emit MASSIVE amounts of Methane- a greenhouse gas far more potent (but also shorter lived) than CO2.

So even with that magic wand, humanity would have a challenging time ahead.

If you find a way to capture CO2 at the scale needed, what would you do with it? Inject it deep underground? Could we be certain that was safe? Could we essentially be creating a time bomb for the planet 100's of thousands or millions of years from now? Podrock is a better person to answer that- I don't know the answer.

It would be great to spin gold from straw and dissociate the CO2 molecule and get pure carbon and O2, but that would require vastly more energy than was generated in the process that made the CO2.

So you are stuck dealing with 100's of billions of tons, trillions of tons of a gas that you have to dispose of- think of all the infrastructure built to deliver oil and Coal to powerplants to be burned, now you need an even larger infrastructure to transport the CO2 gas (you can liquify it of course- with more energy investment). Even If it IS determined that injecting it deep underground is a safe solution I am sure that you would not want to inject it all in the same place, so you have to distribute it globally for sequestration. That is a LOT of gas

At standard temperature and pressure, a cubic meter of CO2 gas has a mass of ~2 kg. The emissions in 2022 were ~36GigaTons=36,000,000,000,000 (36 trillion) kg. At standard temperature and pressure that would be 18trillion cubic meters, or 18,000 cubic kilometers.
Mass of liquified CO2 is ~.68kg/liter, so if you captured just the CO2 emitted in 2022, and liquified it then you would have 53 trillion liters.
Volume of a train tanker car is ~130,000 liters- so it would take ~408 MILLION tanker cars to transport it all.
So it would be a massive undertaking....

There is no substitute for reducing CO2, of course- there are more issues than just warming - it acidifies the oceans and has other effects on the biosphere, but perhaps something like this could help as we reduce the atmospheric CO2?

(I am tired, feel free to check my math- I originally had Chat GPT do the numbers and it was WAY off)