Well the timescale of climate change is on the order of a few decades to a century. The decomposition process is somewhat slow by human standards, but it's still fast compared to a century. In order to effectively remove CO2 from the atmosphere to prevent climate change, it needs to be removed on timescales longer than a century.
Re:We need to take CO2 out of the sky
by jazzyjackson on Tuesday October 05, 2021 @08:39PM
(#28767692)
decomposition doesn’t evaporate the tree into the air, it can build the soil and become habitat for larger animals (which also count as biomass)
You make it sound like a rapid process. Univ of Arizona did a study that showed CO2 emissions of dead trees was lower than living ones due to the rotting process being very slow compared to a living trees normal respiration cycle