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

=== 12.4.1 Introduction ===

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This section complements [[IPCC:Wg3:Chapter:Chapter-7|Chapter 7]] by reviewing recent estimates of food system emissions and assessing options beyond the agriculture, forestry and land use sectors to mitigate food systems GHG emissions. A food system approach enables identification of cross-sectoral mitigation opportunities including both technological and behavioural options. Further, a system approach permits evaluation of policies that do not necessarily directly target primary producers or consumers, but other food system actors, with possibly higher mitigation efficiency. A food system approach was introduced in the IPCC Special Report on Climate Change and Land (SRCCL) ( [[#Mbow--2019|Mbow et al. 2019]] ). Besides major knowledge gaps in the quantification of food system GHG emissions ( [[#12.4.2|Section 12.4.2]] ), the SRCCL authors identified as major knowledge gaps the understanding of the dynamics of dietary change (including behavioural patterns, the adoption of plant-based dietary patterns, and interaction with human health and nutrition of sustainable healthy diets and associated feedbacks); and instruments and mechanisms to accelerate transitions towards sustainable and healthy food systems.

Sufficient food and adequate nutrition are fundamental human needs ( [[#HLPE--2020|HLPE 2020]] ; [[#Ingram--2020|Ingram 2020]] ). Food needs to be grown and processed, transported and distributed, and finally prepared and consumed. Food systems range from traditional, involving only few people and short supply chains, to modern food systems, comprising complex webs involving large numbers of stakeholders and processes that grow and transform food commodities into food products and distribute them globally ( [[#Gómez--2013|Gómez and Ricketts 2013]] ; [[#HLPE--2017|HLPE 2017]] ). A ‘food system’ includes all food chain activities (production, processing, distribution, preparation, consumption of food) and the management of food loss and wastes. It also includes institutions and infrastructures influencing any of these activities, as well as people and systems impacted ( [[#HLPE--2017|HLPE 2017]] ; [[#FAO--2018a|FAO 2018a]] ). Food choices are determined by the food environment, consisting of the ‘physical, economic, political and socio-cultural context in which consumers engage with the food system to acquire, prepare and consume food’ ( [[#HLPE--2017|HLPE 2017]] ). Food system outcomes encompass food and nutrition, productivity, profit and livelihood of food producers and other actors in food value chains, but also social outcomes and the impact on the environment ( [[#Zurek--2018|Zurek et al. 2018]] ). ‘Sustainable healthy diets’ have been defined by FAO and WHO (FAO and [[#WHO--2019|WHO 2019]] ) as ‘dietary patterns that promote all dimensions of individuals’ health and wellbeing; have low environmental pressure and impact; are accessible, affordable, safe and equitable; and are culturally acceptable’.

The SRCCL estimated overall global anthropogenic emissions from food systems to range between 10.8 and 19.1 GtCO 2 -eq yr –1 , equivalent to 21–37% of total anthropogenic emissions ( [[#Mbow--2019|Mbow et al. 2019]] ; [[#Rosenzweig--2020a|Rosenzweig et al. 2020a]] ). The authors identified major knowledge gaps for the GHG emissions inventories of food systems, particularly in providing disaggregated emissions from the food industry and transportation. The food system approach taken in the SRCCL ( [[#Mbow--2019|Mbow et al. 2019]] ) evaluates the synergies and trade-offs of food system response options and their implications for food security, climate change adaptation and mitigation. This integrated framework allows the identification of fundamental attributes of responses to maximise co-benefits, while avoiding maladaptation measures and adverse side effects. A food system approach supports the design of interconnected climate policy responses to tackle climate change, incorporating perspectives of producers and consumers. The SRCCL ( [[#Mbow--2019|Mbow et al. 2019]] ) found that the technical mitigation potential by 2050 of demand-side responses at 0.7–8.0 GtCO 2 -eq yr –1 is comparable to supply-side options at 2.3–9.6 GtCO 2 -eq yr –1 . This shows that mitigation actions need to go beyond food producers and suppliers to incorporate dietary changes and consumers’ behavioural patterns and reveals that producers and consumers need to work together to reduce GHG emissions.

Though total production of calories is sufficient for the world population ( [[#Wood--2018|Wood et al. 2018]] ; [[#Benton--2019|Benton et al. 2019]] ), availability and access to food is unequally distributed, and there is a lack of nutrient-dense foods, fruit and vegetables ( [[#Berners-Lee--2018|Berners-Lee et al. 2018]] ; KC et al. 2018). In 2019, close to 750 million people were food insecure. An estimated 2 billion people lacked adequate access to safe and nutritious food in both quality and quantity ( [[#FAO--2020|FAO et al. 2020]] ). Two billion adults are overweight or obese through inadequate nutrition, with an upward trend globally ( [[#FAO--2019|FAO et al. 2019]] ). Low intake of fruit and vegetables is further aggravated by high intake rates of refined grains, sugar and sodium, together leading to a high risk of non-communicable diseases such as cardiovascular disease and type 2 diabetes ( [[#Springmann--2016|Springmann et al. 2016]] ; [[#Clark--2018|Clark et al. 2018]] ; [[#Clark--2019|Clark et al. 2019]] ; GBD 2017 Diet Collaborators et al. 2019; [[#Willett--2019|Willett et al. 2019]] ) ( ''robust evidence, high agreement'' ). At least 340 million children under five years of age experience lack of vitamins or other essential bio-available nutrients, including almost 200 million suffering from stunting, wasting or overweight ( [[#UNICEF--2019|UNICEF 2019]] ).

[[#Bodirsky--2020|Bodirsky et al. (2020)]] find that the global prevalence of overweight will increase to 39–52% of world population in 2050 (from 29% in 2010; range across the Shared Socio-economic Pathways studied), and the prevalence of obesity to 13–20% (9% in 2010). The prevalence of underweight people was predicted to approximately halve, with absolute numbers stagnating at 0.4–0.7 billion. Although many studies represent future pathways of diets and food systems, there are few holistic and consistent narratives and quantification of the future pathways of diets and food systems ( [[#Mitter--2020|Mitter et al. 2020]] ; [[#Mora--2020|Mora et al. 2020]] ). Alternative pathways for improved diets and food systems have been developed, emphasising climate, environmental and health co-benefits ( [[#Bajželj--2014|Bajželj et al. 2014]] ; [[#Hedenus--2014|Hedenus et al. 2014]] ; [[#Damerau--2016|Damerau et al. 2016]] ; [[#Weindl--2017a|Weindl et al. 2017a]] ; [[#Weindl--2017b|Weindl et al. 2017b]] ; [[#Springmann--2018a|Springmann et al. 2018a]] ; [[#Bodirsky--2020|Bodirsky et al. 2020]] ; [[#Prudhomme--2020|Prudhomme et al. 2020]] ; [[#Hamilton--2021|Hamilton et al. 2021]] ), reduced food waste and closing yield gaps ( [[#Bajželj--2014|Bajželj et al. 2014]] ; [[#Pradhan--2014|Pradhan et al. 2014]] ), nitrogen management ( [[#Bodirsky--2014|Bodirsky et al. 2014]] ), urban and peri-urban agriculture ( [[#Kriewald--2019|Kriewald et al. 2019]] ) and different sustainability targets ( [[#Henry--2018b|Henry et al. 2018b]] ). The UN Food and Agriculture Organization (FAO) has examined three alternative food system scenarios: ‘business as usual’, ‘towards sustainability’, and ‘stratified societies’ ( [[#FAO--2018b|FAO 2018b]] ). Others have identified research priorities or changes in legislation needed to support adoption of improved food systems ( [[#Mylona--2018|Mylona et al. 2018]] ).

Malnutrition aggravates susceptibility of children to various infectious diseases ( [[#França--2009|França et al. 2009]] ; [[#Farhadi--2018|Farhadi and Ovchinnikov 2018]] ), and infectious diseases can also decrease nutrient uptake, thereby promoting malnutrition ( [[#Farhadi--2018|Farhadi and Ovchinnikov 2018]] ). Contamination of food with bacteria, viruses, parasites and microbial toxins can cause foodborne illnesses ( [[#Ricci--2017|Ricci et al. 2017]] ; [[#Abebe--2020|Abebe et al. 2020]] ; [[#Gallo--2020|Gallo et al. 2020]] ), foodborne substances such as food additives and specific proteins can cause adverse reactions, and contamination with toxic chemical substances used in agriculture and food processing can lead to poisoning or chronic diseases ( [[#Gallo--2020|Gallo et al. 2020]] ). Further, health risks from food systems may originate from the use of antibiotics in livestock production and the occurrence of anti-microbial resistance in pathogens (ECDC et al. 2015; [[#Bennani--2020|Bennani et al. 2020]] ), or zoonotic diseases such as COVID-19 ( [[#Gan--2020|Gan et al. 2020]] ; [[#Patterson--2020|Patterson et al. 2020]] ; [[#Vågsholm--2020|Vågsholm et al. 2020]] ).

Modern food systems are highly consolidated, through vertical and horizontal integration ( [[#Swinnen--2007|Swinnen and Maertens 2007]] ; [[#Folke--2019|Folke et al. 2019]] ). This consolidation has led to uneven distribution of power across the food value chain, with influence concentrated among a few actors in the post-farmgate food supply chain (e.g., large food processors and retailers), and has contributed to a loss of indigenous agriculture and food systems, for example on Pacific Islands ( [[#Vogliano--2020|Vogliano et al. 2020]] ). While agricultural producers contribute a higher proportion of GHG emissions compared with other actors in the supply chain, they have relatively little power to change the system ( [[#Clapp--2019|Clapp 2019]] ; [[#Group%20of%20Chief%20Scientific%20Advisors--2020|Group of Chief Scientific Advisors 2020]] ; [[#Leip--2021|Leip et al. 2021]] ).

In 2016, the agriculture, fisheries, and forestry sectors employed 29% of working people; employment within these sectors was 4% in developed countries, down from 9% in 1995, and 57% in least developed countries, down from 71% in 1995 ( [[#World%20Bank--2021|World Bank 2021]] ). Employment in other (non-agriculture) food system sectors, such as the food processing industry and service sectors, differs between food systems. The share of total non-farm food system employment ranges from 10% in traditional food systems (e.g., sub-Saharan Africa), to over 50% in food systems in transition (e.g., Brazil), to high shares (80%) in modern food systems (e.g., US) ( [[#Townsend--2017|Townsend et al. 2017]] ). The share of the food expenditures that farmers receive is decreasing; at the global level, this share has been estimated at 27% in 2015 ( [[#Yi--2021|Yi et al. 2021]] ).

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