There are concurrent media campaigns and publications questioning the use of woody biomass for renewable energy production. Several of them misrepresent on-the-ground forestry practise and bioenergy systems, and associate the use of woody biomass for energy with overexploitation of forests, even permanent deforestation, and “the burning of trees”.
In reality, forest bioenergy is an integral part of the forest sector which responds to bioenergy demand by devising forest management approaches and industrial processes to produce fuels, heat and electricity along with sawlogs, paper and a multitude of other biobased products. The media campaigns also often ignore the many steps that have already been taken towards sustainable forest management, particularly in Europe and North America.
While it is certainly important to identify what is needed to ensure that biomass is produced and used in a responsible way, the misrepresentations within recent soundbites run the risk of discrediting biomass as a sustainable material and energy source altogether – a feat that could have dire consequences for global carbon neutrality ambitions.
February 2021 – Combustion is today the most frequent means of converting woody biomass into energy, particularly in the form of heat and/or power. This can conjure the vision of “burning trees and forests” in the mind of the common reader and even scientists that are unfamiliar with on-the-ground forestry, however the reality is very different! It is already well-recognized that any harvesting of biomass – be it for bioenergy, construction material, paper, or other use – should occur within sustainability boundaries. This implies management and harvesting principles providing safeguards against overharvesting and maintaining ecological sustainability as well as cultural and recreational values.
Nonetheless, current media campaigns are associating bioenergy with irresponsible biomass harvesting and overexploitation of forests without recognizing the many steps that have already been taken to mitigate such risks.
For example, sustainable forest management schemes such as FSC or PEFC endorsed schemes – which are applied to hundreds of millions of hectares of forests globally – contain clear requirements for maintaining forests and their biodiversity. Many countries have adopted similar forest management principles in their national or regional forestry legislations. Moreover, in the European context – the focus of these media campaigns – the recast of the Renewable Energy Directive imposes further requirements to minimise the risk of using forest biomass derived from unsustainable practice. The Directive is to be transposed into national law by all EU Member States before 30 June 2021, and its sustainability requirements must be met also by imported biomass.
Several media campaigns and publications that criticize the use of biomass for energy contain misconceptions, particularly misrepresenting on-the-ground sustainable forestry practices, ignoring that wood production and use is part of the biogenic carbon cycle, and discrediting international greenhouse gas accounting principles. IEA Bioenergy, and recently also the Joint Research Centre (JRC) of the European Commission, have published reports and articles to dispel some of these misconceptions in relation to forest biomass and de-toxify the debate surrounding the sustainability of wood-based bioenergy.
It is important to take a moment to look at some key facts about the use of woody biomass for energy. More specifically:
Do we really need bioenergy? The most important climate change mitigation measure is to transform energy and transport systems as soon as possible so that we can leave fossil carbon in the ground. Sustainable bioenergy is available now, and is compatible with existing energy infrastructure, enabling immediate substitution of coal, natural gas or petroleum fuels. It can therefore play a significant role in supporting energy system transformation to achieve carbon neutrality. There is a lot of focus on renewable electricity – which is also moving the fastest – but other forms of energy, particularly heat and transport fuels, get much less attention. Bioenergy provides renewable heat, electricity and transport fuels and can actually remove CO2 from the atmosphere (going beyond carbon neutrality) when combined with carbon capture and storage of the emitted CO2. It can support the expansion of seasonal or intermittent renewables such as solar or wind energy by providing balancing power and provide solutions for markets that are difficult – or take a long lead-time – to electrify.
Biomass combustion also emits CO2, so how is this better than fossil fuels? CO2 from woody biomass combustion is part of the short-term carbon cycle; the emitted carbon was previously taken up from the atmosphere, and is taken up again by growing trees in the forest. So as long as harvests do not exceed carbon uptake in the forest, it does not increase atmospheric CO2 concentrations. In contrast, fossil fuel use causes a linear flow of carbon from geologic stores to the atmosphere. Just comparing CO2 emissions at the exhaust – as is sometimes done – misses this fundamental difference between biogenic and fossil carbon. What matters is whether increasing use of forest biomass for energy is part of a changing forest management paradigm that brings systematic decreases or increases in the amount of carbon stored in forests. If there is a decrease this diminishes the climate benefits of forest bioenergy. If there is an increase the climate benefit is enhanced.
Are forests being cut to produce bioenergy? Several media campaigns and publications give the impression that complete forest stands are cut for energy alone. However, this does not reflect on-the-ground forestry practice, particularly in Europe or North America, where forests are managed to provide multiple forest products, such as sawnwood, paper, bioenergy and also other biobased products. These different forest products together avoid fossil carbon emissions when replacing products with high carbon footprint such as fossil fuels, cement, steel, or petroleum-based plastics and chemicals. As a case in point, about 90% of global renewable industrial heat consumption is currently based on biomass, mainly in industries that can use their own biomass waste and residues, such as sawmills and the pulp and paper industry. By shifting from fossil fuels to biomass these industries can stop injecting fossil carbon into the atmosphere. Energy efficiency improvements and changes in industrial processes in addition enables them to produce fuels, heat and electricity for use elsewhere, e.g., for heating homes.
Is bioenergy using valuable stemwood? The wood used for bioenergy is not high quality lumber, but typically comprises thinnings, low-quality wood, salvage wood, harvest logging residues, processing residues or wood waste. The Joint Research Centre of the European Commission found that about 50% of wood used for bioenergy in the EU is derived from secondary products, such as forest-based industry by-products and recovered post-consumer wood, 17% from treetops, branches and other residues, and 20% from stemwood – which is mostly coppice wood, small stem thinning wood and harvested stems of poor quality that cannot be used in sawmills or pulp and paper production.
Can we consider bioenergy from woody biomass as renewable? Forest biomass is a renewable resource if forest productivity is maintained, as is prescribed in sustainable forestry principles. Biomass derived from permanent deforestation, however, should not be recognized as renewable, so provisions are needed to exclude such cases from support – both for domestic applications, and for international trade.
All actors in the field already acknowledge the importance of sustainable forest management as a precondition for biomass harvests. “Sustainable forest management” includes, for example, protection of highly biodiverse areas, management that ensures regeneration after harvest, and maintenance of productive capacity – meaning that the managed forest continues to convert atmospheric CO2 into wood. An increase in demand for bioenergy and other forest products – with clear market requirements for sustainable forestry practice – can actually incentivise reforestation and improved forest management leading to healthier forest systems and higher growth compared to the situation where forests are left unmanaged. Forest management generally also reduces the risk of carbon stock losses due to wildfire and diseases/insect outbreaks, issues that are increasingly prevalent under climate change.
The use of woody biomass to meet growing energy demand as well as its carbon neutrality goals should not be excluded because there may be risks of unsustainable practice. Rather, the focus should be on what practices, innovations, and policy regulations are required to ensure sustainable sourcing and efficient conversion to bioenergy and bioproducts.
The IEA Bioenergy Technology Collaboration Programme (IEA Bioenergy TCP) is a global network on research and implementation of bioenergy, established under the International Energy Agency’s Implementing Agreement mechanism. The IEA Bioenergy TCP comprises a world-wide network of experts in every aspect of the value chain of biomass for energy, who are from the research community, institutions of higher education, government agencies and industry. IEA Bioenergy has a rich and excellent history of encouraging and perpetuating the use of biomass as an energy source, to help lessen dependence on fossil fuels, both within and outside its member countries. Further information: www.ieabioenergy.com