Sustainably managed forests can save at least ten times more CO2 than unmanaged forests

WBA, AEBIOM, ABA appeal to policy makers to take scientific results into account when establishing harmonised EU sustainability criteria and future bioenergy policy.

Professor Hubert Hasenauer from the Vienna University of Natural Resources and Applied Life Sciences (silviculture institute) recently published a paper, based on several years of research work, which highlights the major role that managed forests play in carbon emissions mitigation compared to unmanaged forests. One of his main conclusions is: “the effect of the managed forest as a CO2 sink is many times that of the primary forest” - in the example studied at least ten times. The results are based on carbon measurements in European unmanaged forests and sustainable managed forests.

These results can be explained by looking at the relationship between sustainably managed forests and CO2 levels in the atmosphere: Carbon which would be released into the atmosphere during the unmanaged forests phase of decay is put in use in the form of fossil fuel substitution in the case of a managed forest.

The studied unmanaged forests emitted during their life cycle (300 years) almost as much CO2 as they absorbed. As no wood was harvested, no substitution effect occurred. The effect as carbon sink of these forests was therefore minimal.

The managed forest absorbed and emitted more CO2 over the same period of time (balanced result) but in addition, the harvested timber was used as a substitute for fossil energy carriers and allowed to avoid CO2 emissions.

Overall, unmanaged forests release the CO2 they absorb because of natural degradation. The carbon stored in the wood harvested in managed forests is actually released into the atmosphere at the end of the product life but – and this is the important difference to the natural release of carbon in unmanaged forests – only after this carbon has served as material and / or fuel that substitute fossil energy.

The study also points out that changing sustainably managed forests into unmanaged forests does not necessarily cause the stored carbon to increase. The opposite can happen when huge amounts of carbon are released in the atmosphere due to natural damage (eg: insects’ infestations or fungus diseases often followed by forest fires).

Need to increase the use of sustainable solid biomass without administrative burdens

Solid Biomass will still be the most important renewable energy source. “The use of fossil fuels is responsible for 89 percent of global CO2 emissions. Not using the bioenergy potentials now means to postpone the energy transition – from fossil to renewables – for decades. Time we do not have in view of the 2 degree target”, says Heinz Kopetz, President of the World Bioenergy Association.

“Once again it is scientifically proven that it is favourable from a carbon standpoint to use sustainably managed forests also for bioenergy. This is why it is important to ensure that biomass used in Europe originates from forests that are sustainably managed. Given that European forest management is world famous for its sustainability, the introduction and implementation of EU sustainability criteria should support the European way of silviculture, and should not constitute a burden for European producers” says Gustav Melin, President of the European Biomass Association.