Boreal forest management and its effect on atmospheric CO2

In a recent contribution, Cherubini et al. (2011a) analyzed numerically the effect on atmospheric carbon of a single-harvest event in a boreal forest with subsequent combustion of the extracted biomass. Those authors found that a period of increased atmospheric carbon was followed by a period of reduced atmospheric carbon, while harvest was found to be carbon neutral in the long term. First, this article shows that their results are sensitive to the choice of baseline scenario. A more realistic baseline scenario was considered here, where the stand's growth and carbon capture continue in the case of no harvest. This leads to a significantly longer period with increased atmospheric carbon than was found in Cherubini et al. (2011a). Second, the single-harvest approach is supplemented with an analysis of a series of repeated harvests to make the analysis relevant for a discussion of the consequences of the use of biomass for energy purposes, now and in the future. This changes the results fundamentally. It is found that extracting biomass from boreal forests on a permanent basis leads to permanently increased atmospheric carbon concentration when compared with the no-harvest scenario.

► Harvesting of boreal forests increases the level of atmospheric CO2.
► Atmospheric CO2 will increase also in the long term.
► Wood fuels are not carbon neutral, not even in the long term.