There are various ways to remove carbon from the atmosphere, ranging from simple, age-old approaches like planting trees to unproven advanced technologies.
New methods of carbon capture could involve trapping carbon emitted at power plants and storing it underground (a technique known as carbon capture and sequestration) or simply sucking CO2 out of the air and storing it (a concept known as direct air capture).
Futuristic as these technologies sound, they do exist — at least, in prototype forms. And it's quite possible that we'll need to use them. But unfortunately, the methods are far too expensive (or inefficient) to use on large scales, and it wouldn't make sense to implement them without putting a hefty price on carbon.
As the IPCC report says, "the effectiveness of such techniques are unproven at large scale and some may carry significant risks for sustainable development."
For these strategies to really help, they'd have to be improved and made economically viable before we heat the planet too far.