Editing IPCC:AR6/WGIII/Chapter-12 (section)

=== Cross-Working Group Box 3 | Mitigation and Adaptation via the Bioeconomy ===

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'''Authors:''' Henry Neufeldt (Denmark/Germany), Göran Berndes (Sweden), Almut Arneth (Germany), Rachel Bezner Kerr (the United States of America/Canada), Luisa F Cabeza (Spain), Donovan Campbell (Jamaica), Jofre Carnicer Cols (Spain), Annette Cowie (Australia), Vassilis Daioglou (Greece), Joanna House (United Kingdom), Adrian Leip (Italy/Germany), Francisco Meza (Chile), Michael Morecroft (United Kingdom), Gert-Jan Nabuurs (Netherlands), Camille Parmesan (United Kingdom/the United States of America), Julio C. Postigo (the United States of America/Peru), Marta G. Rivera-Ferre (Spain), Raphael Slade (United Kingdom), Maria Cristina Tirado von der Pahlen (the United States of America/Spain), Pramod K. Singh (India), Pete Smith (United Kingdom)

Summary statement

The growing demand for biomass offers both opportunities and challenges to mitigate and adapt to climate change and natural resource constraints ( ''high confidence'' ). Increased technology innovation, stakeholder integration and transparent governance structures and procedures at local to global scales are key to successful bioeconomy deployment maximising benefits and managing trade-offs ( ''hi'' ''gh confidence'' ).

Limited global land and biomass resources accompanied by growing demands for food, feed, fibre, and fuels, together with prospects for a paradigm shift towards phasing out fossil fuels, set the frame for potentially fierce competition for land [[#footnote-001|3]] and biomass to meet burgeoning demands, even as climate change increasingly limits natural resource potentials ( ''high confidence'' ).

Cross-Working Group Box 3

Sustainable agriculture and forestry, technology innovation in bio-based production within a circular economy, and international cooperation and governance of global trade in products to reflect and disincentivise their environmental and social externalities, can provide mitigation and adaptation via bioeconomy development that responds to the needs and perspectives of multiple stakeholders to achieve outcomes that maximise synergies while limiting trade-offs ( ''hi'' ''gh confidence'' ).

Background

There is ''high confidence'' that climate change, population growth and changes in per capita consumption will increase pressures on managed as well as natural and semi-natural ecosystems, exacerbating existing risks to livelihoods, biodiversity, human and ecosystem health, infrastructure, and food systems ( [[#Conijn--2018|Conijn et al. 2018]] ; [[#IPCC--2018|IPCC 2018]] ; [[#IPCC--2019a|IPCC 2019a]] ; [[#Lade--2020|Lade et al. 2020]] ). At the same time, many global mitigation scenarios presented in IPCC assessment reports rely on large GHG emissions reduction in the AFOLU sector and concurrent deployment of reforestation/afforestation and biomass use in a multitude of applications ( [[#Rogelj--2018|Rogelj et al. 2018]] ; Hanssen et al. 2020) (AR6 WGI Chapters 4 and 5, AR6 WGIII Chapters 3 and 7).

Given the finite availability of natural resources, there are invariably trade-offs that complicate land-based mitigation unless land productivity can be enhanced without undermining ecosystem services ( [[#Obersteiner--2016|Obersteiner et al. 2016]] ; [[#Campbell--2017|Campbell et al. 2017]] ; [[#Caron--2018|Caron et al. 2018]] ; [[#Conijn--2018|Conijn et al. 2018]] ; [[#Heck--2018|Heck et al. 2018]] ; Searchinger 2018a; Smith et al. 2019). Management intensities can often be adapted to local conditions with consideration of other functions and ecosystem services, but at a global scale the challenge remains to avoid further deforestation and degradation of intact ecosystems, in particular biodiversity-rich systems (AR6 WGII Cross-Chapter Box NATURAL), while meeting the growing demands. Further, increased land-use competition can affect food prices and impact food security and livelihoods ( [[#To--2015|To and Grafton 2015]] ; [[#Chakravorty--2017|Chakravorty et al. 2017]] ), with possible knock-on effects related to civil unrest ( [[#Abbott--2017|Abbott et al. 2017]] ; [[#D’Odorico--2018|D’Odorico et al. 2018]] ).

Developing new bio-based solutions while mitigating overall biomass demand growth

Many existing bio-based products have significant mitigation potential. Increased use of wood in buildings can reduce GHG emissions from cement and steel production while providing carbon storage ( [[#Churkina--2020|Churkina et al. 2020]] ). Substitution of fossil fuels with biomass in manufacture of cement and steel can reduce GHG emissions where these materials are difficult to replace. Dispatchable power based on biomass can provide power stability and quality as the contribution from solar and wind power increases (AR6 WGIII Chapter 6), and biofuels can contribute to reducing fossil fuel emissions in the transport and industry sectors (AR6 WGIII Chapters 10 and 11). The use of bio-based plastics, chemicals and packaging could be increased, and biorefineries can achieve high resource-use efficiency in converting biomass into food, feed, fuels and other bio-based products ( [[#Aristizábal‐Marulanda--2019|Aristizábal‐Marulanda and Cardona Alzate 2019]] ; [[#Schmidt--2019|Schmidt et al. 2019]] ). There is also scope for substituting existing bio-based products with more benign products. For example, cellulose-based textiles can replace cotton, which requires large amounts of water, chemical fertilisers and pesticides to ensure high yields.

While increasing and diversified use of biomass can reduce the need for fossil fuels and other GHG-intensive products, unfavourable GHG balances may limit the mitigation value. Growth in biomass use may in the longer term also be constrained by the need to protect biodiversity and ecosystems’ capacity to support essential ecosystem services. Biomass use may also be constrained by water scarcity and other resource scarcities, and/or challenges related to public perception and acceptance due to impacts caused by biomass production and use. Energy conservation and efficiency measures and deployment of technologies and systems that do not rely on carbon, such as carbon-free electricity supporting, ''inter alia'' , electrification of transport as well as industry processes and residential heating ( [[#IPCC--2018|IPCC 2018]] ; [[#UNEP--2019|UNEP 2019]] ), can constrain the growth in biomass demand when countries seek to phase out fossil fuels and other GHG-intensive products while providing an acceptable standard of living. Nevertheless, demand for bio-based products may become high where full decoupling from carbon is difficult to achieve (e.g., aviation, bio-based plastics and chemicals) or where carbon storage is an associated benefit (e.g., wood buildings, BECCS, biochar for soil amendments), leading to challenging trade-offs (e.g., food security, biodiversity) that need to be managed in environmentally sustainable and socially just ways.

Changes on the demand side as well as improvements in resource-use efficiencies within the global food and other bio-based systems can also reduce pressures on the remaining land resources. For example, dietary changes toward more plant-based food (where appropriate) and reduced food waste can provide climate change mitigation along with health benefits ( [[#Willett--2019|Willett et al. 2019]] ) (AR6 WGIII Sections 7.4 and 12.4) and other co-benefits with regard to food security, adaptation and land use ( [[#Mbow--2019|Mbow et al. 2019]] ; [[#Smith--2019a|Smith et al. 2019a]] ) (AR6 WGII Chapter 5). Advancements in the provision of novel food and feed sources (e.g., cultured meat, insects, grass-based protein feed and cellular agriculture) can also limit the pressures on finite natural resources ( [[#Parodi--2018|Parodi et al. 2018]] ; [[#Zabaniotou--2018|Zabaniotou 2018]] ) (AR6 WGIII [[#12.4|Section 12.4]] ).

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Circular bioeconomy

Circular economy approaches (AR6 WGIII [[#12.6|Section 12.6]] ) are commonly depicted by two cycles, where the biological cycle focuses on regeneration in the biosphere and the technical cycle focuses on reuse, refurbishment and recycling to maintain value and maximise material recovery ( [[#Mayer--2019a|Mayer et al. 2019a]] ). Biogenic carbon flows and resources are part of the biological carbon cycle, but carbon-based products can be included in, and affect, both the biological and the technical carbon cycles ( [[#Kirchherr--2017|Kirchherr et al. 2017]] ; [[#Winans--2017|Winans et al. 2017]] ; [[#Velenturf--2019|Velenturf et al. 2019]] ). The integration of circular economy and bioeconomy principles has been discussed in relation to organic waste management ( [[#Teigiserova--2020|Teigiserova et al. 2020]] ), societal transition and policy development ( [[#European%20Commission--2018|European Commission 2018]] ; [[#Bugge--2019|Bugge et al. 2019]] ) as well as COVID-19 recovery strategies ( [[#Palahí--2020|Palahí et al. 2020]] ). To maintain the natural resource base, circular bioeconomy emphasises sustainable land use and the return of biomass and nutrients to the biosphere when it leaves the technical cycle.

Scarcity is an argument for adopting circular economy principles for the management of biomass, as for non-renewable resources. Waste avoidance, product reuse and material recycling keep down resource use while maintaining product and material value. However, reuse and recycling are not always feasible, for example when biofuels are used for transport and bio-based biodegradable chemicals are used to reduce ecological impacts, where losses to the environment are unavoidable. A balanced approach to management of biomass resources could start from the perspective of value preservation within the carbon cycle, with possible routes for biomass use based on the carbon budget defined by the Paris Agreement, principles for sustainable land use and natural ecosystem protection.

Land-use opportunities and challenges in the bioeconomy

Analyses of synergies and trade-offs between adaptation and mitigation in the agriculture and forestry sectors show that outcomes depend on context, design and implementation, so actions have to be tailored to the specific conditions to minimise adverse effects ( [[#Kongsager--2018|Kongsager 2018]] ). This is supported in literature analysing the nexus between land, water, energy and food in the context of climate change, which consistently concludes that addressing these different domains together rather than in isolation would enhance synergies and reduce trade-offs ( [[#Obersteiner--2016|Obersteiner et al. 2016]] ; [[#D’Odorico--2018|D’Odorico et al. 2018]] ; [[#Soto%20Golcher--2018|Soto Golcher and Visseren-Hamakers 2018]] ; [[#Froese--2019|Froese et al. 2019]] ; [[#Momblanch--2019|Momblanch et al. 2019]] ).

Nature-based solutions addressing climate change can provide opportunities for sustainable livelihoods as well as multiple ecosystem services, such as flood risk management through floodplain restoration, saltmarshes, mangroves or peat renaturation ( [[#UNEP--2021|UNEP 2021]] ; AR6 WGII Cross-Chapter Box NATURAL). Climate-smart agriculture can increase productivity while enhancing resilience and reducing GHG emissions inherent to production ( [[#Lipper--2014|Lipper et al. 2014]] ; [[#Bell--2018|Bell et al. 2018]] ; [[#FAO--2019b|]] [[#FAO--2019|FAO 2019]] b ; [[#Singh--2021|Singh and Chudasama 2021]] ). Similarly, climate-smart forestry considers the whole value chain and integrates climate objectives into forest sector management through multiple measures (from strict reserves to more intensively managed forests) providing mitigation and adaptation benefits ( [[#Nabuurs--2018|Nabuurs et al. 2018]] ; [[#Verkerk--2020|Verkerk et al. 2020]] ) (AR6 WGIII [[IPCC:Wg3:Chapter:Chapter-7#7.3|Section 7.3]] ).

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Agroecological approaches can be integrated into a wide range of land management practices to support a sustainable bioeconomy and address equity considerations ( [[#HLPE--2019|HLPE 2019]] ). Relevant land-use practices, such as agroforestry, intercropping, organic amendments, cover crops and rotational grazing, can provide mitigation and support adaption to climate change via food security, livelihoods, biodiversity and health co-benefits ( [[#Ponisio--2015|Ponisio et al. 2015]] ; [[#Garibaldi--2016|Garibaldi et al. 2016]] ; [[#D’Annolfo--2017|D’Annolfo et al. 2017]] ; [[#Bezner%20Kerr--2019|Bezner Kerr et al. 2019]] ; [[#Clark--2019|Clark et al. 2019]] b; [[#Córdova--2019|Córdova et al. 2019]] ; [[#HLPE--2019|HLPE 2019]] ; [[#Mbow--2019|Mbow et al. 2019]] ; [[#Renard--2019|Renard and Tilman 2019]] ; [[#Sinclair--2019|Sinclair et al. 2019]] ; [[#Bharucha--2020|Bharucha et al. 2020]] ; [[#Bezner%20Kerr--2021|Bezner Kerr et al. 2021]] ) (AR6 WGII Cross-Chapter Box NATURAL). Strategic integration of appropriate biomass production systems into agricultural landscapes can provide biomass for bioenergy and other bio-based products while providing co-benefits such as enhanced landscape diversity, habitat quality, retention of nutrients and sediment, erosion control, climate regulation, flood regulation, pollination and biological pest and disease control ( [[#Christen--2013|Christen and Dalgaard 2013]] ; [[#Asbjornsen--2014|Asbjornsen et al. 2014]] ; [[#Holland--2015|Holland et al. 2015]] ; [[#Ssegane--2015|Ssegane et al. 2015]] ; [[#Dauber--2016|Dauber and Miyake 2016]] ; [[#Milner--2016|Milner et al. 2016]] ; [[#Ssegane--2016|Ssegane and Negri 2016]] ; [[#Styles--2016|Styles et al. 2016]] ; [[#Zumpf--2017|Zumpf et al. 2017]] ; [[#Cacho--2018|Cacho et al. 2018]] ; [[#Alam--2019|Alam and Dwivedi 2019]] ; [[#Cubins--2019|Cubins et al. 2019]] ; [[#HLPE--2019|HLPE 2019]] ; [[#Olsson--2019|Olsson et al. 2019]] ; [[#Zalesny--2019|Zalesny et al. 2019]] ; Englund et al. 2020) (AR6 WGIII Box 12.3). Such approaches can help limit environmental impacts from intensive agriculture while maintaining or increasing land productivity and biomass output.

Transitions from conventional to new biomass production and conversion systems include challenges related to cross-sector integration and limited experience with new crops and land use practices, including needs for specialised equipment ( [[#Thornton--2015|Thornton and Herrero 2015]] ; [[#HLPE--2019|HLPE 2019]] ) (AR6 WGII [[IPCC:Wg3:Chapter:Chapter-5#5.1|Section 5.1]] 0). Introduction of agroecological approaches and integrated biomass/food crop production can result in lower food crop yields per hectare, particularly during transition phases, potentially causing indirect landuse change, but can also support higher and more stable yields, reduce costs, and increase profitability under climate change ( [[#Muller--2017|Muller et al. 2017]] ; [[#Seufert--2017|Seufert and Ramakutty 2017]] ; [[#Barbieri--2019|Barbieri et al. 2019]] ; [[#HLPE--2019|HLPE 2019]] ; [[#Sinclair--2019|Sinclair et al. 2019]] ; [[#Smith--2019a|Smith et al. 2019a]] ; [[#Smith--2020|Smith et al. 2020]] ). Crop diversification, organic amendments, and biological pest control ( [[#HLPE--2019|HLPE 2019]] ) can reduce input costs and risks of occupational pesticide exposure and food and water contamination ( [[#González-Alzaga--2014|González-Alzaga et al. 2014]] ; [[#EFSA--2017|EFSA 2017]] ; [[#Mie--2017|Mie et al. 2017]] ), reduce farmers’ vulnerability to climate change (e.g., droughts and spread of pests and diseases affecting plant and animal health) ( [[#Delcour--2015|Delcour et al. 2015]] ; [[#FAO--2020|FAO 2020]] ) and enhance provisioning and sustaining ecosystem services, such as pollination ( [[#D’Annolfo--2017|D’Annolfo et al. 2017]] ; [[#Sinclair--2019|Sinclair et al. 2019]] ).

Barriers toward wider implementation include absence of policies that compensate land owners for providing enhanced ecosystem services and other environmental benefits, which can help overcome short-term losses during the transition from conventional practices before longer-term benefits can accrue. Other barriers include limited access to markets, knowledge gaps, financial, technological or labour constraints, lack of extension support and insecure land tenure ( [[#Jacobi--2017|Jacobi et al. 2017]] ; [[#Kongsager--2017|Kongsager 2017]] ; [[#Hernández-Morcillo--2018|Hernández-Morcillo et al. 2018]] ; [[#Iiyama--2018|Iiyama et al. 2018]] ; [[#HLPE--2019|HLPE 2019]] ). Regional-level agroecology transitions may be facilitated by co-learning platforms, farmer networks, private sector, civil society groups, regional and local administration and other incentive structures (e.g., price premiums, access to credit, regulation) ( [[#Coe--2014|Coe et al. 2014]] ; [[#Pérez-Marin--2017|Pérez-Marin et al. 2017]] ; Mier y Terán Giménez [[#Cacho--2018|Cacho et al. 2018]] ; [[#HLPE--2019|HLPE 2019]] ; [[#Valencia--2019|Valencia et al. 2019]] ; SAEPEA 2020). With the right incentives, improvements can be made with regard to profitability, making alternatives more attractive to land owners.

Governing the solution space

Literature analysing the synergies and trade-offs between competing demands for land suggest that solutions are highly contextualised in terms of their environmental, socio-economic and governance-related characteristics, making it difficult to devise generic solutions ( [[#Haasnoot--2020|Haasnoot et al. 2020]] ). Aspects of spatial and temporal scale can further enhance the complexity, for instance where transboundary effects across jurisdictions or upstream-downstream characteristics need to be considered, or where climate change trajectories might alter relevant biogeophysical dynamics ( [[#Postigo--2021|Postigo and Young 2021]] ). Nonetheless, there is broad agreement that taking the needs and perspectives of multiple stakeholders into account in a transparent process during negotiations improves the chances of achieving outcomes that maximise synergies while limiting trade-offs ( [[#Ariti--2018|Ariti et al. 2018]] ; [[#Metternicht--2018|Metternicht 2018]] ; [[#Favretto--2020|Favretto et al. 2020]] ; [[#Kopáček--2021|Kopáček 2021]] ; [[#Muscat--2021|Muscat et al. 2021]] ). Yet differences in agency and power between stakeholders or anticipated changes in access to or control of resources can undermine negotiation results even if there is a common understanding of the overarching benefits of more integrated environmental agreements and the need for greater coordination and cooperation to avoid longer-term losses to all ( [[#Aarts--2010|Aarts and Leeuwis 2010]] ; [[#Weitz--2017|Weitz et al. 2017]] ). There is also the risk that strong local participatory processes can become disconnected from broader national plans, and thus fail to support the achievement of national targets. Thus, connection between levels is needed to ensure that ambition for transformative change is not derailed at local level ( [[#Aarts--2010|Aarts and Leeuwis 2010]] ; [[#Postigo--2021|Postigo and Young 2021]] ).

Decisions on land uses between biomass production for food, feed, fibre or fuel, as well as nature conservation or restoration and other uses (e.g., mining, urban infrastructure), depend on differences in perspectives and values. Because the availability of land for diverse biomass uses is invariably limited, setting priorities for land-use allocations therefore first depends on making the perspectives underlying what is considered as ‘high-value’ explicit ( [[#Fischer--2007|Fischer et al. 2007]] ; [[#Garnett--2015|Garnett et al. 2015]] ; [[#De%20Boer--2018|De Boer and Van Ittersum 2018]] ;

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[[#Muscat--2020|Muscat et al. 2020]] ). Decisions can then be made transparently based on societal norms, needs and the available resource base. Prioritisation of land use for the common good therefore requires societal consensus building embedded in the socio-economic and cultural fabric of regions, societies and communities. Integration of local decision-making with national planning ensures local actions complement national development objectives.

International trade in the global economy today provides important opportunities to connect producers and consumers, effectively buffering price volatilities and potentially offering producer countries access to global markets, which can be seen as an effective adaptation measure ( [[#Baldos--2015|Baldos and Hertel 2015]] ; [[#Costinot--2016|Costinot et al. 2016]] ; [[#Hertel--2016|Hertel and Baldos 2016]] ; [[#Gouel--2021|Gouel and Laborde 2021]] ) (AR6 WGII [[IPCC:Wg3:Chapter:Chapter-5#5.1|Section 5.1]] 1). But there is also clear evidence that international trade and the global economy can enhance price volatility, lead to food price spikes and affect food security due to climate and other shocks, as seen recently due to the COVID-19 pandemic ( [[#Cottrell--2019|Cottrell et al. 2019]] ; [[#WFP-FSIN--2020|WFP-FSIN 2020]] ; [[#Verschuur--2021|Verschuur et al. 2021]] ) (AR6 WGII [[IPCC:Wg3:Chapter:Chapter-5#5.1|Section 5.1]] 2). The continued strong demand for food and other bio-based products, mainly from high- and middle-income countries, therefore requires better cooperation between nations and global governance of trade to more accurately reflect and disincentivise their environmental and social externalities. Trade in agricultural and extractive products driving land-use change in tropical forest and savanna biomes is of major concern because of the biodiversity impacts and GHG emissions incurred in their provision ( [[#Hosonuma--2012|Hosonuma et al. 2012]] ; [[#Forest%20Trends--2014|Forest Trends 2014]] ; [[#Smith--2014|Smith et al. 2014]] ; [[#Henders--2015|Henders et al. 2015]] ; [[#Curtis--2018|Curtis et al. 2018]] ; [[#Pendrill--2019|Pendrill et al. 2019]] ; [[#Seymour--2019|Seymour and Harris 2019]] ; [[#Kissinger--2021|Kissinger et al. 2021]] ) (AR6 WGII Tropical Forests Cross-Chapter Paper).

In summary, there is significant scope for optimising use of land resources to produce more biomass while reducing adverse effects ( ''high confidence'' ). Context-specific prioritisation, technology innovation in bio-based production, integrative policies, coordinated institutions and improved governance mechanisms to enhance synergies and minimise trade-offs can mitigate the pressure on managed as well as natural and semi-natural ecosystems ( ''medium confidence'' ). Yet, energy conservation and efficiency measures, and deployment of technologies and systems that do not rely on carbon-based energy and materials, are essential for mitigating biomass demand growth as countries pursue ambitious climate goals ( ''hi'' ''gh confidence'' ).

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