More information about hugelkultur, which uses available carbon rich plant matter as the basis for a raised bed.
Building a hugel is one way to practice carbon sequestration on a small scale. The carbon they this tree ate up from the atmosphere will be captured in the soil and used to grow more plants that will then consume more carbon from the atmosphere.
Imagine doing this on a massive scale, burying carbon rich matter in our agricultural fields to regenerate the soil's carbon supply and prevent the release of more C02