Trees capture co2 into the biosphere, and when they do so it is temporary (~100 years by the time they've decomposed and released it back in to the atmosphere). Still, planting trees helps hold more co2 from the atmosphere and needs to be part of the solution. Especially if we can re-green areas that are currently barren, like deserts.

Proper sequestering, which I agree doesn't really exist yet, is to capture co2 back into the geosphere.