Editing IPCC:AR6/SRCCL/Chapter-1 (section)

=== 1.3.3 Value chain management ===

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==== 1.3.3.1 Supply management ====

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Food losses from harvest to retailer. Approximately one-third of losses and waste in the food system occurs between crop production and food consumption, increasing substantially if losses in livestock production and overeating are included (Gustavsson et al. 2011 <sup>[[#fn:r726|726]]</sup> ; Alexander et al. 2017 <sup>[[#fn:r727|727]]</sup> ). This includes on-farm losses, farm to retailer losses, as well retailer and consumer losses (Section 1.3.3.2).

Post-harvest food loss – on farm and from farm to retailer – is a widespread problem, especially in developing countries (Xue et al. 2017 <sup>[[#fn:r728|728]]</sup> ), but are challenging to quantify. For instance, averaged for eastern and southern Africa an estimated 10–17% of annual grain production is lost (Zorya et al. 2011 <sup>[[#fn:r729|729]]</sup> ). Across 84 countries and different time periods, annual median losses in the supply chain before retailing were estimated at about 28 kg per capita for cereals or about 12 kg per capita for eggs and dairy products (Xue et al. 2017 <sup>[[#fn:r730|730]]</sup> ). For the year 2013, losses prior to the reaching retailers were estimated at 20% (dry weight) of the production amount (22% wet weight) (Gustavsson et al. 2011 <sup>[[#fn:r731|731]]</sup> ; Alexander et al. 2017 <sup>[[#fn:r732|732]]</sup> ). While losses of food cannot be realistically reduced to zero, advancing harvesting technologies (Bradford et al. 2018 <sup>[[#fn:r733|733]]</sup> ; Affognon et al. 2015 <sup>[[#fn:r734|734]]</sup> ), storage capacity (Chegere 2018 <sup>[[#fn:r735|735]]</sup> ) and efficient transportation could all contribute to reducing these losses with co-benefits for food availability, the land area needed for food production and related GHG emissions.

'''Stability of food supply, transport and distribution.''' Increased climate variability enhances fluctuations in world food supply and price variability (Warren 2014 <sup>[[#fn:r736|736]]</sup> ; Challinor et al. 2015 <sup>[[#fn:r737|737]]</sup> ; Elbehri et al. 2017 <sup>[[#fn:r738|738]]</sup> ). ‘Food price shocks’ need to be understood regarding their transmission across sectors and borders and impacts on poor and food insecure populations, including urban poor subject to food deserts and inadequate food accessibility (Widener et al. 2017 <sup>[[#fn:r739|739]]</sup> ; Lehmann et al. 2013 <sup>[[#fn:r740|740]]</sup> ; Le 2016 <sup>[[#fn:r741|741]]</sup> ; FAO 2015b <sup>[[#fn:r742|742]]</sup> ). Trade can play an important stabilising role in food supply, especially for regions with agro-ecological limits to production, including water scarce regions, as well as regions that experience short-term production variability due to climate, conflicts or other economic shocks (Gilmont 2015 <sup>[[#fn:r743|743]]</sup> ; Marchand et al. 2016 <sup>[[#fn:r744|744]]</sup> ). Food trade can either increase or reduce the overall environmental impacts of agriculture (Kastner et al. 2014 <sup>[[#fn:r745|745]]</sup> ). Embedded in trade are virtual transfers of water, land area, productivity, ecosystem services, biodiversity, or nutrients (Marques et al. 2019 <sup>[[#fn:r746|746]]</sup> ; Wiedmann and Lenzen 2018 <sup>[[#fn:r747|747]]</sup> ; Chaudhary and Kastner 2016 <sup>[[#fn:r748|748]]</sup> ) with either positive or negative implications (Chen et al. 2018 <sup>[[#fn:r749|749]]</sup> ; Yu et al. 2013 <sup>[[#fn:r750|750]]</sup> ). Detrimental consequences in countries in which trade dependency may accentuate the risk of food shortages from foreign production shocks could be reduced by increasing domestic reserves or importing food from a diversity of suppliers (Gilmont 2015 <sup>[[#fn:r751|751]]</sup> ; Marchand et al. 2016 <sup>[[#fn:r752|752]]</sup> ).

Climate mitigation policies could create new trade opportunities (e.g., biomass) (Favero and Massetti 2014 <sup>[[#fn:r753|753]]</sup> ) or alter existing trade patterns. The transportation GHG footprints of supply chains may be causing a differentiation between short and long supply chains (Schmidt et al. 2017 <sup>[[#fn:r754|754]]</sup> ) that may be influenced by both economics and policy measures (Section 5.4). In the absence of sustainable practices and when the ecological footprint is not valued through the market system, trade can also exacerbate resource exploitation and environmental leakages, thus weakening trade mitigation contributions (Dalin and Rodríguez-Iturbe 2016 <sup>[[#fn:r755|755]]</sup> ; Mosnier et al. 2014 <sup>[[#fn:r756|756]]</sup> ; Elbehri et al. 2017 <sup>[[#fn:r757|757]]</sup> ). Ensuring stable food supply while pursuing climate mitigation and adaptation will benefit from evolving trade rules and policies that allow internalisation of the cost of carbon (and costs of other vital resources such as water, nutrients). Likewise, future climate change mitigation policies would gain from measures designed to internalise the environmental costs of resources and the benefits of ecosystem services (Elbehri et al. 2017 <sup>[[#fn:r758|758]]</sup> ; Brown et al. 2007 <sup>[[#fn:r759|759]]</sup> ).

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==== 1.3.3.2 Demand management ====

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'''Dietary change.''' Demand-side solutions to climate mitigation are an essential complement to supply-side, technology and productivity driven solutions ( ''high confidence'' ) (Creutzig et al. 2016 <sup>[[#fn:r760|760]]</sup> ; Bajželj et al. 2014 <sup>[[#fn:r761|761]]</sup> ; Erb et al. 2016b <sup>[[#fn:r762|762]]</sup> ; Creutzig et al. 2018 <sup>[[#fn:r763|763]]</sup> ) (Sections 5.5.1 and 5.5.2). The environmental impacts of the animal-rich ‘western diets’ are being examined critically in the scientific literature (Hallström et al. 2015 <sup>[[#fn:r764|764]]</sup> ; Alexander et al. 2016b <sup>[[#fn:r765|765]]</sup> ; Alexander et al. 2015 <sup>[[#fn:r766|766]]</sup> ; Tilman and Clark 2014 <sup>[[#fn:r767|767]]</sup> ; Aleksandrowicz et al. 2016 <sup>[[#fn:r768|768]]</sup> ; Poore and Nemecek 2018 <sup>[[#fn:r769|769]]</sup> ) (Section 5.4.6). For example, if the average diet of each country were consumed globally, the agricultural land area needed to supply these diets would vary 14-fold, due to country differences in ruminant protein and calorific intake (–55% to +178% compared to existing cropland areas). Given the important role enteric fermentation plays in methane (CH4) emissions, a number of studies have examined the implications of lower animal-protein diets (Swain et al. 2018 <sup>[[#fn:r770|770]]</sup> ; Röös et al. 2017 <sup>[[#fn:r771|771]]</sup> ; Rao et al. 2018 <sup>[[#fn:r772|772]]</sup> ). Reduction of animal protein intake has been estimated to reduce global green water (from precipitation) use by 11% and blue water (from rivers, lakes, groundwater) use by 6% (Jalava et al. 2014 <sup>[[#fn:r773|773]]</sup> ). By avoiding meat from producers with above-median GHG emissions and halving animal-product intake, consumption change could free-up 21 million km <sup>2</sup> of agricultural land and reduce GHG emissions by nearly 5 GtCO <sub>2</sub> -eq yr <sup>–1</sup> or up to 10.4 GtCO <sub>2</sub> -eq yr <sup>–1</sup> when vegetation carbon uptake is considered on the previously agricultural land (Poore and Nemecek 2018 <sup>[[#fn:r774|774]]</sup> , 2019).

Diets can be location and community specific, are rooted in culture and traditions while responding to changing lifestyles driven for instance by urbanisation and changing income. Changing dietary and consumption habits would require a combination of non-price (government procurement, regulations, education and awareness raising) and price incentives (Juhl and Jensen 2014 <sup>[[#fn:r775|775]]</sup> ) to induce consumer behavioural change with potential synergies between climate, health and equity (addressing growing global nutrition imbalances that emerge as undernutrition, malnutrition, and obesity) (FAO 2018b <sup>[[#fn:r776|776]]</sup> ).

'''Reduced waste and losses in the food demand system.''' Global averaged per capita food waste and loss (FWL) have increased by 44% between 1961 and 2011 (Porter et al. 2016 <sup>[[#fn:r777|777]]</sup> ) and are now around 25–30% of global food produced (Kummu et al. 2012 <sup>[[#fn:r778|778]]</sup> ; Alexander et al. 2017 <sup>[[#fn:r779|779]]</sup> ). Food waste occurs at all stages of the food supply chain from the household to the marketplace (Parfitt et al. 2010 <sup>[[#fn:r780|780]]</sup> ) and is found to be larger at household than at supply chain levels. A meta-analysis of 55 studies showed that the highest share of food waste was at the consumer stage (43.9% of total) with waste increasing with per capita GDP for high-income countries until a plateaux at about 100 kg cap <sup>–1</sup> yr <sup>–1</sup> (around 16% of food consumption) above about 70,000 USD cap <sup>–1</sup> (van der Werf and Gilliland 2017 <sup>[[#fn:r781|781]]</sup> ; Xue et al. 2017 <sup>[[#fn:r782|782]]</sup> ). Food loss from supply chains tends to be more prevalent in less developed countries where inadequate technologies, limited infrastructure, and imperfect markets combine to raise the share of the food production lost before use.

There are several causes behind food waste including economics (cheap food), food policies (subsidies) as well as individual behaviour (Schanes et al. 2018 <sup>[[#fn:r783|783]]</sup> ). Household level food waste arises from overeating or overbuying (Thyberg and Tonjes 2016 <sup>[[#fn:r784|784]]</sup> ). Globally, overconsumption was found to waste 9–10% of food bought (Alexander et al. 2017 <sup>[[#fn:r785|785]]</sup> ).

Solutions to FWL thus need to address technical and economic aspects. Such solutions would benefit from more accurate data on the loss-source, loss-magnitude and causes along the food supply chain. In the long run, internalising the cost of food waste into the product price would more likely induce a shift in consumer behaviour towards less waste and more nutritious, or alternative, food intake (FAO 2018b <sup>[[#fn:r786|786]]</sup> ). Reducing FWL would bring a range of benefits for health, reducing pressures on land, water and nutrients, lowering emissions and safeguarding food security. Reducing food waste by 50% would generate net emissions reductions in the range of 20 to 30% of total food-sourced GHGs (Bajželj et al. 2014 <sup>[[#fn:r787|787]]</sup> ). SDG 12 (“Ensure sustainable consumption and production patterns”) calls for per capita global food waste to be reduced by one-half at the retail and consumer level, and reducing food losses along production and supply chains by 2030.

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