Today there is much concern about the increasing carbon dioxide (CO2) content of the atmosphere, because it increases the global temperature, which melts the ice sheets and makes the sea level rise. When a tree grows, it absorbs (captures, sequesters) CO2, a building block of wood. An unmanaged virgin forest does not absorb CO2, because growth is balanced by wood decay and its associated CO2 emission — see the entry “Carbon Dioxide (CO2), carbon credits, carbon sequestration” in the book. After all, if a virgin forest went on and on absorbing CO2, where would it end?
In managed and logged forests, on the other hand, there is no wood decay. It is true that the forest products derived from the logged forest do not last forever, and when they eventually decay they too emits CO2, but some of these products have a very long life; e.g. wood panelling, high quality paper, structural timber.
I should like to see some virgin forest preserved in every type of forest, for scientific and other reasons, and they do serve as carbon sinks, but from an active CO2 capture point of view they are no good.
Mikael Grut, 30.9.2014