Many different data sources are used to produce the Sankey diagram (Figure 14, p.49). In a main source, the Joint Wood Energy Enquiry, pellets are entirely categorised as a secondary source, while in the National Renewable Energy Action Plans progress reports, wood pellets are at times reported as both primary and secondary wood, the proportion of which depends on the share of different feedstocks. We acknowledge that pellets are manufactured using primary as well as secondary woody biomass, and this is highlighted in the report (see pages 41, 42, 82 and Glossary term for Fuelwood).

We did not assess stemwood per se because it is not possible to make that assessment in a generic way (e.g., without having a full picture of the full management cycle, the tree size, location, species etc).

The carbon impact of a pathway is not only determined by the feedstock considered. Any result of carbon accounting of ‘stemwood’ is strongly influenced by the assumptions and the method of the analysis. This is one of the caution messages that we convey in the report and the reason why we describe the study boundary conditions and assumptions in so much detail (see e.g. section 5.6 on pag. 97).

In the report we refer often to a 2014 study where we assessed the direct effect of the use of stemwood for bioenergy on climate change mitigation (Agostini et al., 2014). In that study, for instance, we assumed that additional stemwood was harvested and used for energy and nothing else was changed in the forest management (i.e. using a ceteris paribus approach). It was determined that, under such an assumption, there is no short-term (10-20 years) benefit and hardly any medium-term (<50 years) benefit at all from using stemwood for energy with respect to coal and natural gas.

However, by taking a systemic perspective and including potential indirect effects, a different result might be obtained. For instance, in case of additional demand of stemwood for energy, would that lead to a change in the forest management so that more wood is produced? This is what we call in the report ‘additional’ biomass, namely biomass that would not otherwise have been produced without the demand for biomass for bioenergy. In this case, the benefits to the climate in short and medium term can be positive. These results can be found in several studies in the literature.

Interpreting the results of this type of assessment is complicated because the assumptions chosen can sway the result from positive to negative, and in a recent study (Giuntoli et al., 2020), we critique several studies for using unrealistic assumptions for the indirect effects driven by bioenergy demand. For this reason in the report we recommend not to look at the ‘results’ of these isolated exercises, and not to look for the ‘right’ answer, but rather to look for the policy conditions that would stimulate the win-win solutions.

No. CWD are deadwood components, decaying and very slowly emitting carbon to the atmosphere. On the other hand, when harvesting a living stem that would otherwise continue to grow and absorb carbon, the analysis would need to account also for this ‘foregone sequestration’. So coarse woody debris, if left behind, decays slowly and provide habitat, nutrients etc – thus it has an important ecological role - but live trees, if not harvested, live on, continue to absorb and store carbon and have a completely different ecological role.

Woody biomass for energy does not only concern by-products from sawmills. The wood-based bioenergy sector is partially based on secondary woody biomass (forest-based industry by-products, wood pellets, and recovered wood), making up almost half of the reported wood use (49%). This is an EU average. The type of feedstock used vary from country to country, see the wood resource balance sheets at Member State level. It should be noted that ‘secondary woody biomass’ includes wood pellets, which are not necessarily always produced using only secondary woody biomass (see question 1).

Experts may determine whether or not using wood/forest damaged by insects or fungi for bioenergy is sustainable on a case-by-case basis. In many EU countries national legislation require to remove infested wood from forest in order to reduce the risk of further spreading the infestation (see section 5.8.1.3, p.112; Table 7). In addition, EU legislation may require taking eradication measures in some specific cases (e.g. This was the case with the problem of pinewood nematodes in Portugal and Spain, see Council Directive 2000/29/EC). It is a common practice in the EU to burn infested wood after removal, because wood working industry do not accept infested wood. However, we report the findings from a recent study that found that there are negative effects from salvage logging on the ecosystems, particularly after fires and windthrow disturbances. These negative impacts could be mitigated with proper planning, for example if some areas are left as they are (i.e. no salvage logging takes place and if snags are retained, see e.g. Lindenmayer et al. (2017)).

The answer is 'it depends', and will differ depending on whether or not the wood is used for bioenergy or for other purposes where the carbon may be stored (e.g. material uses). To calculate the potential carbon mitigation of a bioenergy pathway (from a Life Cycle perspective), we need to compare the two scenarios: 1) using biomass for bioenergy vs. 2) leaving the biomass in the forest (i.e. the 'counterfactual').

The final result depends on many different assumptions (which we describe in the report). A very important assumption is whether one accounts solely for the 'direct' impacts or if one attempts to expand the analysis to include also second-order, indirect effects.

In the case described in the question, one would have to consider:

i) What is happening to the tree infested by the bark beetles? Is it going to die? In that case the counterfactual scenario would see the dead tree slowly rotting and thus slowly releasing its biogenic-CO₂ to the atmosphere. This scenario would be close to the archetype nr. 1 that we assess in the report (CWD removal).

ii) However, those are only the direct impacts. What happens in the whole forest ecosystem in case the infested tree is left to decay? Maybe the infestation spreads further, or faster, than it would have if the tree were removed from the forest. In that case, one should not stop at the direct effects, but should really evaluate the carbon impacts in the whole forest system in both scenarios. In the latter case, maybe the infestation spreads out of control, a large number of trees are killed and the forest ecosystem becomes a source of CO₂ rather than continuing being a sink. Another possibility is that the salvage logging allows for quicker reforestation and regrowth of the forest, which would not be happening if the dead tree were left in the forest. Further to consider is how the land is reforested (monoculture vs mixed indigenous species) and the reforestation can be an opportunity to reforest according to ecological principles, with more biodiverse and climate-friendly forest.

Additionally, one would have to consider whether the 'salvage' operation is mandated by law, in which case the counterfactual in point i ('deadwood left to decay in the forest') would be an unrealistic assumption.

Thus, the answer to this question depends on how and which of the situations above is assumed to take place. The importance of indirect effects is the main reason why we did not explicitly qualify bioenergy from salvage operations in the report. However, we did mention a recent paper (Thorn et al., 2018) that looked at the biodiversity implications of salvage logging.

The sustainability analysis is not directly linked to the quantitative analysis of current sources and uses, but rather focuses on different future potential forest management practices. See the section Choice of pathways in this FAQ for the reasons for choosing the pathways in question. In any case, pathways that consider the removal of logging residues do indeed partially address the description above ‘waste and residues and biomass that has no alternative use and would decompose if they couldn’t be used for energy’.

We do not include stemwood from eucalyptus plantations, which we consider to have been planted for pulp mainly. According to the report of Unrau et al. there are about 18 million hectares of coppice in Southern EU MS. Eucalyptus plantations in PT and ES cover in total less than 1.4 million hectares, and not all of them are coppices (data from the countries NFIs).

The assumption we made regarding the origin of the stemwood is conservative, in that we did not include species we know are mostly used for other purposes. But this does not mean we claim Eucalyptus are not burned at all, and that part of the stemwood might come from Eucalyptus coppices. It might also partially be burned, but given the numbers mentioned above, such amounts would not change the overall broad conclusion in our report.

Wood that is left in the forest after forestry logging operations is commonly referred to as ‘logging residues’. These materials generally include woody debris from final felling (e.g. branches, leaves, stumps, roots, tops, bark), small trees from thinning and clearing operations, and generally unmerchantable stem wood. The specific definition of which materials constitute ‘logging residues’ is important, because different types of deadwood play different ecological roles and, consequently, specific impacts are associated to their removal. Our analysis only focused on woody debris produced during final felling and we differentiate among the following three types of residues:

** For various definitions of FWD in guidelines around the world see Titus et al.

References:

1) Giuntoli J., Barredo J.I., Avitabile V.,Camia A., Cazzaniga N.E., Grassi G., Jasinevičius G., Jonsson R., Marelli L., Robert N., Agostini A., Mubareka S. The quest for sustainable forest bioenergy: win-win solutions for climate and biodiversity, Renewable and Sustainable Energy Reviews, Volume 159,2022,112180,ISSN 1364-0321, https://doi.org/10.1016/j.rser.2022.112180

2) Koivula M, Vanha-Majamaa I. Experimental evidence on biodiversity impacts of variable retention forestry, prescribed burning, and deadwood manipulation in Fennoscandia. Ecol Proc 2020;9. https://doi.org/10.1186/s13717-019-0209-1

3) Sändström J, Bernes C, Junninen K, Lõhmus A, Macdonald E, Müller J, et al. Impacts of dead wood manipulation on the biodiversity of temperate and boreal forests. A systematic review. J Appl Ecol 2019;56:1770 –81. https://doi.org/10.1111/1365-2664.13395

4) Titus B.D., Brown K., Helmisaari H.S., Vanguelova E., Stupak I., Evans A., et al. Sustainable forest biomass: a review of current residue harvesting guidelines. Energy Sustain Soc, 11 (2021), pp. 1-33, https://doi.org/10.1186/s13705-021-00281-w

The first part of the report establishes the main feedstocks being used for energy. However, the analysis of the pathways in Chapter 5 has a different scope: rather than assessing the impacts of current supplies, it aims to assess the pathways that could be used if the demand for bioenergy were to increase. It was never the scope to assess the sustainability of current pathways or forest management in general.

The study does quite the opposite, and focusses on the potential pathways that are likely to be considered as ‘best’ pathways, or ‘silver bullets’. The three interventions analysed by the JRC would, under the current legislation at the time of writing, realistically provide additional biomass for bioenergy. Furthermore, we think it will be useful to inform current and future policies.

Other pathways that do not produce additional biomass have been shown to have  negative results for the climate perspective (as explained in details by Agostini et al., 2014 and Giuntoli et al., 2020).

Regarding the sustainability assessment of secondary woody biomass: first, there is no direct impact on biodiversity for this pathway. Second, an increase in bioenergy demand is more likely to intensify the competition on primary sources since secondary sources are already used, but mainly, the supply of by-products is inelastic, thus increasing demand for bioenergy means that additional biomass needs to be supplied. An increase in the use of wood for material would lead to more by-products available, however, renewable energy policies are not directly driving such changes.

Although this practice is currently not dominant in Europe for bioenergy production, it could theoretically become so if there is an increased demand for forest-based bioenergy (the study has not carried any quantitative assessment of this likelihood). Furthermore, this practice does occur in exporting countries to the EU and sustainability criteria of the REDII apply irrespective of the geographical origin of the biomass. Since increasing bioenergy demand may place an increased demand for wood, this may lead to indirect drivers for conversion of natural forests into highly-productive plantations. Finally, scenarios including plantations to produce biomass for energy are hypothesis that are present in several modelling exercises attempting to estimate quantities of wood that could be used for energy.

The choice of interventions to be looked at is described in the report at pag. 104, section 5.7.2.

There were several reasons to choose these interventions:

1. They produce additional biomass (i.e. not affecting existing uses in other sectors);
2. They are forward looking (i.e. we did not look at what is happening, but to what might happen with an increase in bioenergy demand);
3. They are considered aspirational (i.e. we did not look at what is happening, but to what might be desirable to happen).

We focus on these pathways because they  produce additional biomass. Pathways that imply increased harvest are known to have negative carbon impacts (e.g. see Agostini et al., 2014) and thus we knew there would be no trade-offs to be assessed. Furthermore, if the wood is diverted from existing uses, then there would be many indirect effects to take into account and we only looked at direct impacts, so we would miss most of the potential effects.

Finally, several other interventions would fit the criteria to be included, but we did not have time to look into them, they are mentioned though in our recommendations for ‘future research’.

The JRC had six months to conduct the study and a choice had to be taken on the scientific approach, which we knew should be useful for policy. Since the study is part of the Biodiversity Strategy 2030 Action plan, we decided to focus on environmental sustainability. In any case we think it is far more robust to assess environmental implications of specific pathways completely independently of these drivers because an analysis based on causal links of specific drivers would entail assumptions that would be very difficult to demonstrate systematically.

The aim of the study is to support EU policies and did not look into how national policies address the risks outlined in this report. Although it is up to each country to define how and for which purposes its forests are managed, many EU policies do have an impact on forest management. Our aim was therefore to provide a current EU-level picture of wood-use for energy, in interaction with other parts of the wood-based value chains and to evaluate which pathways could support an increase in the use of wood for energy, while reaching the climate change mitigation goal and the biodiversity preservation and restoration objectives.

Because the term is not used in the report.

We applied the FAO definition: “Plantation forest: Planted Forest that is intensively managed and meet ALL the following criteria at planting and stand maturity: one or two species, even age class, and regular spacing.”

The REDII sustainability criteria (as defined at the time of the writing of the report) have no specific provisions establishing thresholds for removals of residues (see Article 29, paragraph 6). The report did not assess these thresholds, these are set under all national legislation. Finally, Sustainable Forest Management certification standards often have provisions only for retention of coarse woody debris (CWD) but not for stumps or fine woody debris (FWD).

Yes this is correct, provided that the locally-established removal thresholds are respected. However, we do not claim this to be the only win-win option in absolute terms, but only within the pathways assessed in detail in the report, there might be other win-win pathways that we have not analysed. Further, it is important to clarify the definitions used in the report to categorize the pathways (p. 108-109, Section 5.8.1.1):

• Fine Woody Debris (FWD) (including slash, i.e. tops and branches);
• Coarse Woody Debris (CWD) (including snags, standing dead trees, and high stumps);
• Low-stumps.

This is mainly a matter of forest management and therefore will change from place to place, which is why we remained generic in our recommendations. The main point that we found in our research is that it is crucial to maintain a certain amount and diversity of deadwood across a forest landscape. Local forest ecologists would certainly be able to define appropriate conditions and thresholds.

In terms of the thresholds: voluntary forest certification schemes and their national interpretations usually recommend a minimum amount of Coarse Woody Debris that must be left in the stand when this is harvested, but they mainly focus on large deadwood (standing or laying). Additionally, whether the operational thresholds are ecologically sufficient to maintain biodiversity is still debated (see e.g. Johansson et al. (2013), Jonsson et al. (2016), and Kuuluvainen et al. (2019)). For other types of deadwood (i.e. low stumps and tops and branches), these thresholds, when they are defined, they are usually set within national or regional forestry legislation, or management guidelines (see this recent paper by Titus et al. (2021), published after the report). For instance, the Swedish Forestry Agency has recommendations in place that at least 20% of residues are left at every clear-felled area (as reported by Nilsson et al., 2018).

While this is a valid example of 'threshold', it is not really a landscape threshold, since it is defined at each clear-cut stand. Instead, we used the term landscape as interpreted within the principles of ecosystem approach. For the specific case of saproxylic species, which are affected by the presence or absence of deadwood, our review found that the appropriate spatial scale to manage deadwood retention is bigger than a stand (i.e. the smallest unit at which forests are managed), and rather at regional or sub-regional scale (e.g. see Mason and Zapponi (2016)). We cannot comment whether this is a widespread practice or not.

The request for this report arose from the political will, expressed in the Biodiversity Strategy, to re-evaluate all policy efforts in light of the new priorities of environmental protection captured in the EU Green Deal. So the efforts in the JRC report are in line with the precautionary principle: in case of new relevant evidence, this should be included to guarantee high environmental protection.

The JRC study does not make this statement, no. The results of the analysis show that nearly half (49%) of the woody bioenergy at EU-level is sourced from secondary forest biomass and that 37% is wood from primary sources, including 4% industrial roundwood, 9% unaccounted and 24% fuelwood (see Figure 8, p.41). The remaining 14% is uncategorised wood source.

The JRC report highlighted an important gap (about 20%) between the reported amount of woody biomass used in the manufacturing of wood-based products for energy production and the reported amount reported as sources. We may go so far as to attribute to the energy sector, as explained in Chapter 3. We should acknowledge that a part may be associated to fuelwood harvesting for households or small-scale commercial consumption in rural areas that is not recorded by official national statistics. This does not mean that such harvesting is illegal or not subject to sustainable forest management legislation.

It is not possible to directly attribute any of the biomass to illegal logging with certainty and based on the data sources we have used. Satellite imagery and field observations can be a good ally in this type of analysis, and the former offers timely data with a large geographical coverage. We should consider complementarity of Earth Observation tools and field-based expertise, as discussed on p.73.

Rather than assessing the impacts of current supplies, this study aims to assess a number of selected pathways that could theoretically be used if the demand for bioenergy were to increase. It was never the scope to assess current pathways or forest management in general. See the section Choice of pathways for more FAQ.

Bioenergy was assumed, under the previous architecture of climate and energy package (2020) as climate neutral. Under the 2030 framework, adopted in 2018 but only in place since Jan 2021, bioenergy is no longer assumed climate neutral. Under the LULUCF Regulation, all annual harvest emissions are counted as an emission of the carbon stored while the tree was growing. Exceptions to this are made for wood that is stored as a solid product or for dead wood left in the forest. Bioenergy combustion emissions are therefore not accounted in the energy sector (under the 2018 Renewable Energy Directive, nor the Emission Trading System) because they have already been addressed at their source.

However, the ETS will require, from January 2022, an allowance to be surrendered for any biomass feedstock that does not meet RED II criteria.

Legislation is already in place setting climate targets, the comparison needs to be between different renewable energy sources, not with fossil sources. The climate target can be reached with or without bioenergy, so it is incorrect to state that if bioenergy is not promoted, we would rely on fossil sources.

We say that forest bioenergy is not considered climate neutral within the whole EU Climate and Energy package since the EU LULUCF regulation accounts for changes in the forest carbon sink also associated to bioenergy. While this ensures that the carbon impacts of bioenergy is accounted for and this should encourage climate-positive pathways if they are identified and implemented on the national level, it does not automatically by default guarantee that forest bioenergy contributes to climate change mitigation.

This is not totally correct. What we say is "The carbon impact of any change in management or wood use relative to a historical period is fully counted in the LULUCF sector, against the FRLs” and “the only [increase in] bioenergy emissions that may remain unaccounted for are those associated with the age-structure dynamics, that is, with the increase in harvest which is exclusively due to more area of forest becoming mature after 2020 relative to the reference period.” Thus, there may be some (limited) increase in bioenergy emissions that do not count towards target compliance (much less than in the past, under Kyoto) – although it is important to note that these emissions are reported in the LULUCF sector. This is one of the reasons why we noted the opportunities arising from starting to treat LULUCF as any other sector.

Not really, this is not our message at all. The report states that strategically,  in terms of climate action as long as carbon emissions and sequestration is accounted for properly (through the now improved LULUCF regulation), then it does not matter whether any specific pathway of bioenergy contributes to climate change mitigation, as long as the overall decarbonization target is reached. It is up to the strategic autonomy of each country/region to decide how to use their natural resources and energy system.

Nonetheless, the use of product-based LCA allows a different perspective and to assess each supply chain. While we argue against this approach as a regulatory tool, we endorse it as a strategic tool (see section 5.6, page 97, and see JRC Policy Brief on the use of Life Cycle Assessment (LCA) to evaluate environmental impacts of the bioeconomy). A product-based perspective allows for defining a clear causality between bioenergy and its impacts, and it thus offers important additional evidence for the decision-making process and a suitable tool for identifying forest bioenergy feedstock types that are most likely to achieve climate benefits in short- to medium-term. It can also empower consumers, allowing a more informed buying decision.

That is why the final synthesis in Chapter 5 considers very broad bins of payback times (Short-term, Likely Medium Term, Unlikely medium term, Long-term/never). Assumptions on the analysis can make a difference in many cases, especially on the substitution factors for fossil energy (i.e. which fossil fuel is assumed to be substituted and whether perfect substitution is considered). Many of these aspects are evaluated and discussed in details already in a decade of literature on the topic. These two publications condense our view of these aspects: Agostini et al., 2019 & Giuntoli et al., 2020.

We did not go into details about payback times because this topic has been already tackled in the past years. See for instance Giuntoli et al., 2015. In the paper we ran a rather complex analysis to assess the climate impact of using forest residues with different decay rates. However, the calculations in the background deal in a simpler way with carbon emissions (provided in the Supplementary Material of the paper). The way we tackled carbon emissions is by using a simple exponential decay for the residues left in the forest and compare this trend with the GHG emissions from the use of fossil fuels; the point where the two curves intersect would be the payback time.

Pathway 9 is discussed in details in the report as its impacts can change depending on the specific conditions. Especially for climate impact, Giuntoli et al., 2015 details the climate impacts of using residues with different decay rates. Stumps decaying in boreal conditions usually have a long payback time, however if the decay rate is higher (e.g. warmer climates or smaller deadwood types) then the payback time might be shorter and the pathway would move upwards in Fig. 42.

For pathway 1, we stand by our conclusions based on the recommendations from forest ecologists as published in the literature, which are clearly to increase the retention levels of CWD. The special case of natural disturbances has not been assessed by us (see specific questions in section Bioenergy feedstocks, questions 5 & 6.)

We did not assess whether or not EU’s current biomass energy use is sustainable or not sustainable. The variety of conditions found in Europe, and the significant data gaps, do not allow us to draw generalised and definitive EU level conclusions. We call for an effort to improve data reporting because a greater certainty on the composition of the bioenergy mix is a prerequisite to understand the impacts of using wood-based bioenergy in the EU on climate and biodiversity. Sustainability is a broad concept that needs to be defined and operationalised. In our case we took stock mainly of the REDII definition of 'sustainable' which focuses on biodiversity/ecosystem condition and GHG emissions. The operationalisation of the concept may depend on many factors such as local socio-economic and biophysical context, prevailing societal values, knowledge claims. These may originate potentially conflicting views that are among the reasons for the heated debate around bioenergy sustainability. Our attempt is to provide evidence and to highlight the current uncertainties to inform the debate.

Our report does not assess the impacts of current bioenergy practices because those are embedded in the more ‘traditional’ forest management practice which has already been the subject of extensive literature investigation. We instead looked at a selected number potential future pathways which could supply ‘additional’ biomass, i.e. growing biomass that would not be produced in the absence of bioenergy demand (thus enhancing the terrestrial carbon sink) or using biomass, such as residues and wastes, that would otherwise decompose or burn on site (thus reducing GHG emissions to the atmosphere). These interventions are often high in the agenda of climate change mitigation strategies and it was thus necessary to investigate whether they could have adverse effects on ecosystems and biodiversity.

It is important to highlight that our findings should not be interpreted to capture the whole range of possible benefits and risks associated to forest management interventions linked to bioenergy.

However, as we state in Chapter 6: as it has become clear for food crops, any additional demand of wood for bioenergy will simply add up to the overall demand of wood for other uses, meaning that even if wood for energy is subjected to strict sustainability criteria, wood for other purposes might still be produced through detrimental practices and pathways. As highlighted by the EU Bioeconomy Strategy, a holistic governance is required to move towards a sustainable and circular bioeconomy. Therefore, better defining and expanding sustainable forest management to all forest products consumed in Europe, irrespective of final use and geographical origin, would be a much more effective measure to promote a more sustainable forest-based sector as a whole.

So, to answer the question: we did not analyse current forest management practices or the bioenergy sector as a whole because: 1) there is not enough data; 2) impacts of traditional forest management are well studied and they have resulted in the current status of forest ecosystems; 3) rather than the impact of bioenergy sector we should look at the impacts of the whole forest sector. Nonetheless, we provide data to make sure that wood demand for energy does not incentivize negative forest management practices in the short-medium term.

The JRC operated under an interservice group (ISG) to conduct this study. This should be considered as a positive context because the ISG steered the study towards policy-relevant questions from all perspectives within the EC. Policy DGs contributed equally in the ISG and the study is a scientific output of the JRC. This is mentioned in the first paragraph of the inset of the report: “This publication is a Science for Policy report by the Joint Research Centre (JRC), the European Commission’s science and knowledge service. It aims to provide evidence-based scientific support to the European policymaking process. The scientific output expressed does not imply a policy position of the European Commission”. Furthermore, the report was prepared by a JRC’s multi-disciplinary team (see short biographies of authors, p.176-177 in the report), thus covering a wide range of technical expertise necessary for addressing cross-cutting questions.

On a more general note, information regarding the governance and independent role of the JRC in policy-support is available in the JRC Science Hub.