In the long run, presupposing a constant size of forest, this is approximately true, but 1 if you harvest sustainably and use the lumber for building long live

In the long run, presupposing a constant size of forest, this is approximately true, but 1 if you harvest sustainably and use the lumber for building long lived structures, it might be a sink in the timescale that's important for combating global warming. 2 these forests have been sinking a lot, stands to reason they could alternatively be expanding, which would make them a carbon sink for the duration of the expansion