This. Early trees sequestered a whole bunch of carbon in their structure (and there wasn’t efficient methods of breaking down lignin at the time, so the carbon

This. Early trees sequestered a whole bunch of carbon in their structure (and there wasn’t efficient methods of breaking down lignin at the time, so the carbon stayed in the ground instead of rotting and returning to the sky). If we build long-lived structures out of wood or other carbon bearing materials whose carbon source is the atmosphere, we’ll be doing the same thing as trees but with human civilization as the organism.