[wgolsen]

> there's no significant process that turns trees into sequestered carbon for longer than the trees' lifespan.

There is of course lumber, which can sequester CO2 for decades or hundreds of years. Lumber sequestration currently only amounts to ~1% of global annual carbon emissions, but regionally it can be big (9% in Sweden) [1]. Lumber might have a bigger impact if purposefully employed for sequestration and prioritized over other carbon positive building materials.

1 https://www.pnas.org/content/116/29/14526