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

=== 12.4.3 Mitigation Opportunities ===

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GHG emissions from food systems can be reduced by targeting direct or indirect GHG emissions in the supply chain including enhanced carbon sequestration, by introducing sustainable production methods such as agroecological approaches which can reduce system-level GHG emissions of conventional food production and also enhance resilience ( [[#HLPE--2019|HLPE 2019]] ), by substituting food products with high GHG intensities with others of lower GHG intensities, by reducing food over-consumption, and/or by reducing food loss and waste. The substitution of food products with others that are more sustainable and/or healthier is often called ‘dietary shift’.

Clark et al. (2020) showed that even if fossil fuel emissions were eliminated immediately, food system emissions alone would jeopardise the achievement of the 1.5ºC target and threaten the 2ºC target. They concluded that both demand-side and supply-side strategies are needed, including a shift to a diet with lower GHG intensity and rich in plant-based ‘conventional’ foods (e.g., pulses, nuts), or new food products that could support dietary shift. Such dietary shift needs to overcome socio-cultural, knowledge, and economic barriers to significantly achieve GHG mitigation ( [[#12.4.5|Section 12.4.5]] ).

Food losses occur at the farm, post-harvest and during the food processing/wholesale stages of a food supply chain, while in the final retail and consumption stages the term food waste is used ( [[#HLPE--2014|HLPE 2014]] ). Typically, food losses are linked to technical issues such as lack of infrastructure and storage, while food waste is often caused by socio-economic and behavioural factors. Mitigation opportunities through reducing food waste and loss exist in all food supply chain stages and are described in the sub-sections below.

Food system mitigation opportunities are divided into five categories as given in Table 12.8:

• Food production from agriculture, aquaculture, and fisheries (Chapter 7.4 and [[#12.4.3.1|Section 12.4.3.1]] )

'''•''' Controlled-environment agriculture ( [[#12.4.3.2|Section 12.4.3.2]] )

'''•''' Emerging food production technologies ( [[#12.4.3.3|Section 12.4.3.3]] )

'''•''' Food processing industries ( [[#12.4.3.4|Section 12.4.3.4]] )

• Storage and distribution ( [[#12.4.3|Section 12.4.3]] .5)

Food system mitigation opportunities can be either incremental or transformative ( [[#Kugelberg--2021|Kugelberg et al. 2021]] ). Incremental options are based on mature technologies, for which processes and causalities are understood, and their implementation is generally accepted by society. They do not require a substantial change in the way food is produced, processed, or consumed and might lead to a (slight) shift in production systems or preferences. Transformative mitigation opportunities have wider food system implications and usually coincide with a significant change in food choices. They are based on technologies that are not yet mature and are expected to require further innovation ( [[#Klerkx--2020|Klerkx and Rose 2020]] ), and/or mature technologies that might already be part of some food systems but are not yet widely accepted and have transformative potential if applied at large scale, for example consumption of insects ( [[#Raheem--2019a|Raheem et al. 2019a]] ). Many emerging technologies might be seen as a further step in agronomic development where land-intensive production methods relying on the availability of naturally-available nutrients and water are successively replaced with crop variants and cultivation practices reducing these dependencies at the cost of larger energy input ( [[#Winiwarter--2014|Winiwarter et al. 2014]] ). Others suggest a shift to agroecological approaches combining new scientific insights with local knowledge and cultural values ( [[#HLPE--2019|HLPE 2019]] ). Food system transformation can lead to regime shifts or (fast) disruptions ( [[#Pereira--2020|Pereira et al. 2020]] ) if driven by events that are out of control of private or public measures and have a ‘crisis’ character (e.g., BSE) ( [[#Skuce--2013|Skuce et al. 2013]] ).

Table 12.8 summarises the main characteristics of food system mitigation opportunities, their effect on GHG emissions, and associated co-benefits and adverse effects.

'''Table 12.8 | Food system mitigation''' '''opportunities.'''

{| class="wikitable"
|-
! colspan="2"| '''Food system mit''' '''igation options'''

''I: incremental; T: transformative''

! '''Direct and indirect effect on GHG mitigation'''

''D: direct emissions except emissions from energy use; E: energy demand; M: material demand; FL: food losses; FW:'' ''food waste''

''Direction of effect on GHG mitigation:'' ''+'' ''increased mitigation;'' ''0'' ''neutral;'' ''–'' ''decreased mitigation''

! '''Co-benefits/adverse effects'''

''H: health aspects; A: animal welfare; R: resource use; L: land demand; E: ecosystem services; 0: neutral''

''+'' ''co-benefits;'' ''–'' ''adverse effects''

! '''Source'''

|-
| rowspan="5"| Food from agriculture, aquaculture and fisheries

| (I) Dietary shift, in particular increased share of plant-based protein sources

| D+ ↓ GHG footprint

| A+ Animal welfare

L+ Land sparing

H+ Good nutritional properties, potentially ↓ risk from zoonotic diseases, pesticides and antibiotics

| 1–5

|-
| (I/T) Digital agriculture

| D+ ↑ Logistics

| L+ Land sparing

R+ ↑ Resource use efficiencies

| 6–7

|-
| (T) Gene technology

| D+ ↑ Productivity or efficiency

| H+ ↑ Nutritional quality

E0 ↓ Use of agrochemicals; ↑ probability of off-target impacts

| 7–11

|-
| (I) Sustainable intensification, Land-use optimisation

| D+ ↓ GHG footprint

E0 Mixed effects

| L+ Land sparing

R– Might ↑ pollution/biodiversity loss

| 7, 12

|-
| (I) Agroecology

| D+ ↓ GHG/area, positive micro-climatic effects E+ ↓ Energy, possibly ↓ transport FL+ Circular approaches

| E+ Focus on co-benefits/ecosystem services

R+ Circular, ↑ nutrient and water use efficiencies

| 13–17

|-
| Controlled-environment agriculture

| (T) Soilless agriculture

| D+ ↑ productivity, weather independent

FL+ harvest on demand

E- Currently ↑ energy demand, but ↓ transport, building spaces can be used for renewable energy

| R+ Controlled loops ↑ nutrient and water use efficiency

L+ Land sparing

H+ Crop breeding can be optimised for taste and/or nutritional quality

| 18–24

|-
| rowspan="4"| Emerging food production technologies

| (T) Insects

| D0 Good feed conversion efficiency

FW+ Can be fed on food waste

| H0 Good nutritional qualities but attention to allergies and food safety issues required

| 25–28

|-
| (I/T) Algae and bivalves

| D+ ↓ GHG footprints

| A+ Animal welfare

L+ Land sparing

H+ Good nutritional qualities; risk of heavy metal and pathogen contamination

R+ Biofiltration of nutrient-polluted waters

| 29–32

|-
| (I/T) Plant-based alternatives to animal-based food products

| D+ No emissions from animals, ↓ inputs for feed

| A+ Animal welfare

L+ Land sparing

H+ Potentially ↓ risk from zoonotic diseases, pesticides and antibiotics; but ↑ processing demand

| 31–33

|-
| (T) Cellular agriculture (including cultured meat, microbial protein)

| D+ No emissions from animals, high protein conversion efficiency

E– ↑ Energy need

FLW+ ↓ Food loss and waste

| A+ Animal welfare

R+ ↓ Emissions of reactive nitrogen or other pollutants

H0 Potentially ↓ risk from zoonotic diseases, pesticides and antibiotics; ↑ research on safety aspects needed

| 3, 24

34–42

|-
| rowspan="4"| Food processing and packaging

| (I) Valorisation of by-products, food loss and waste logistics and management

| M+ Substitution of bio-based materials

FL+ ↓ of food losses

|
| 43–44

|-
| (I) Food conservation

| FW+ ↓ Food waste

E0 ↑ energy demand but also energy savings possible (e.g., refrigeration, transport)

|
| 45–46

|-
| (I) Smart packaging and other technologies

| FW+ ↓ Food waste

M0 ↑ Material demand and ↑ material-efficiency

E0 ↑ Energy demand; energy savings possible

| H+ Possibly ↑ freshness/reduced food safety risks

| 46–49

|-
| (I) Energy efficiency

| E+ ↓ Energy

|
| 50

|-
| rowspan="5"| Storage and distribution

| (I) Improved logistics

| D+ ↓ Transport emissions

FL+ ↓ Losses in transport

FW– Easier access to food could ↑ food waste

|
| 46–47

51–53

|-
| (I) Specific measures to reduce food waste in retail and food catering

| FW+ ↓ Food waste

E+ ↓ Downstream energy demand

M+ ↓ Downstream material demand

|
| 54–56

|-
| (I) Alternative fuels/ transport modes

| D+ ↓ Emissions from transport

|
|-
| (I) Energy efficiency

| E+ ↓ Energy in refrigeration, lightening, climatisation

|
| 57–58

|-
| (I) Replacing refrigerants

| D+ ↓ Emissions from the cold chain

|
| 50

59–60

|}

Sources: [1] [[#McDermott--2017|McDermott and Wyatt (2017)]] ; [2] [[#Foyer--2016|Foyer et al. (2016)]] ; [3] [[#Semba--2021|Semba et al. (2021)]] ; [4] [[#Weindl--2020|Weindl et al. (2020)]] ; [5] [[#Hertzler--2020|Hertzler et al. (2020)]] ; [6] [[#Finger--2019|Finger et al. (2019)]] ; [7] [[#Herrero--2020|Herrero et al. (2020)]] ; [8] [[#Steinwand--2020|Steinwand and Ronald (2020)]] ; [9] [[#Zhang--2020a|Zhang et al. (2020a)]] ; [10] [[#Ansari--2020|Ansari et al. (2020)]] ; [11] [[#Eckerstorfer--2021|Eckerstorfer et al. (2021)]] ; [12] [[#Folberth--2020|Folberth et al. (2020)]] ; [13] [[#HLPE--2019|HLPE (2019)]] ; [14] [[#Wezel--2009|Wezel et al. (2009)]] ; [15] [[#Van%20Zanten--2018|Van Zanten et al. (2018)]] ; [16] [[#Van%20Zanten--2019|Van Zanten et al. (2019)]] ; [17] [[#van%20Hal--2019|van Hal et al. (2019)]] ; [18] [[#Beacham--2019|Beacham et al. (2019)]] ; [19] [[#Benke--2017|Benke and Tomkins (2017)]] ; [20] [[#Gómez--2018|Gómez and Gennaro Izzo (2018)]] ; [21] [[#Maucieri--2018|Maucieri et al. (2018)]] ; [22] [[#Rufí-Salís--2020|Rufí-Salís et al. (2020)]] ; [23] [[#Shamshiri--2018|Shamshiri et al. (2018)]] ; [24] [[#Graamans--2018|Graamans et al. (2018)]] ; [25] [[#Fasolin--2019|Fasolin et al. (2019)]] ; [26] [[#Garofalo--2019|Garofalo et al. (2019)]] ; [27] [[#Parodi--2018|Parodi et al. (2018)]] ; [28] [[#Varelas--2019|Varelas (2019)]] ; [29] [[#Gentry--2020|Gentry et al. (2020)]] ; [30] [[#Peñalver--2020|Peñalver et al. (2020)]] ; [31] [[#Torres-Tiji--2020|Torres-Tiji et al. (2020)]] ; [32] [[#Willer--2020|Willer and Aldridge (2020)]] ; [33] [[#Fresán--2019|Fresán et al. (2019)]] ; [34] [[#Mejia--2019|Mejia et al. (2019)]] ; [35] [[#Tuomisto--2019|Tuomisto (2019)]] ; [36] [[#Thorrez--2019|Thorrez and Vandenburgh (2019)]] ; [37] [[#Tuomisto--2011|Tuomisto and Teixeira de Mattos (2011)]] ; [38] [[#Mattick--2015|Mattick et al. (2015)]] ; [39] [[#Mattick--2018|Mattick (2018)]] ; [40] [[#Souza%20Filho--2019|Souza Filho et al. (2019)]] ; [41] [[#Chriki--2020|Chriki and Hocquette (2020)]] ; [42] [[#Hadi--2021|Hadi and Brightwell (2021)]] ; [43] [[#Göbel--2015|Göbel et al. (2015)]] ; [44] [[#Caldeira--2020|Caldeira et al. (2020)]] ; [45] [[#Silva--2019|Silva and Sanjuán (2019)]] ; [46] [[#FAO--2019a|FAO (2019a)]] ; [47] [[#Molina-Besch--2019|Molina-Besch et al. (2019)]] ; [48] [[#Poyatos-Racionero--2018|Poyatos-Racionero et al. (2018)]] ; [49] [[#Müller--2019|Müller and Schmid (2019)]] ; [50] [[#Niles--2018|Niles et al. (2018)]] ; [51] [[#Lindh--2016|Lindh et al. (2016)]] ; [52] [[#Wohner--2019|Wohner et al. (2019)]] ; [53] [[#Bajželj--2020|Bajželj et al. (2020)]] ; [54] [[#Buisman--2019|Buisman et al. (2019)]] ; [55] [[#Albizzati--2019|Albizzati et al. (2019)]] ; [56] [[#Liu--2016|Liu et al. (2016)]] ; [57] [[#Chaomuang--2017|Chaomuang et al. (2017)]] ; [58] [[#Lemma--2014|Lemma et al. (2014)]] ; [59] [[#McLinden--2017|McLinden et al. (2017)]] ; [60] [[#Gullo--2017|Gullo et al. (2017)]] . Food from Agriculture, Aquaculture, and Fisheries.

Agricultural food production systems range from smallholder subsistence farms to large animal production factories, in open spaces, greenhouses, rural areas or urban settings.

'''Dietary shift:''' Studies demonstrate that a shift to diets rich in plant-based foods, particularly pulses, nuts, fruits and vegetables, such as vegetarian, pescatarian or vegan diets, could lead to substantial reduction of greenhouse gas emissions as compared to current dietary patterns in most industrialised countries, while also providing health benefits and reducing mortality from diet-related non-communicable diseases ( [[#Springmann--2018a|Springmann et al. 2018a]] ; [[#Chen--2019|Chen et al. 2019]] ; [[#Willett--2019|Willett et al. 2019]] ; [[#Bodirsky--2020|Bodirsky et al. 2020]] ; [[#Costa%20Leite--2020|Costa Leite et al. 2020]] ; [[#Ernstoff--2020|Ernstoff et al. 2020]] ; [[#Jarmul--2020|Jarmul et al. 2020]] ; [[#Semba--2020|Semba et al. 2020]] ; [[#Theurl--2020|Theurl et al. 2020]] ; [[#Hamilton--2021|Hamilton et al. 2021]] ).

Pulses such as beans, chickpeas, or lentils, have a protein composition complementary to cereals, providing together all essential amino acids ( [[#Foyer--2016|Foyer et al. 2016]] ; [[#McDermott--2017|McDermott and Wyatt 2017]] ). Bio-availability of proteins in foods is influenced by several factors, including amino acid composition, presence of anti-nutritional factors, and preparation method ( [[#Hertzler--2020|Hertzler et al. 2020]] ; [[#Weindl--2020|Weindl et al. 2020]] ; [[#Semba--2021|Semba et al. 2021]] ). Soy beans, in particular, have a well-balanced amino acid profile with high bio-availability ( [[#Leinonen--2019|Leinonen et al. 2019]] ). Pulses are part of most traditional diets ( [[#Semba--2021|Semba et al. 2021]] ) and supply up to 10–35% of protein in low-income countries, but consumption decreases with increasing income and they are globally only a minor share of the diet ( [[#McDermott--2017|McDermott and Wyatt 2017]] ). Pulses play a key role in crop rotations, fixing nitrogen and breaking disease cycles, but yields of pulses are relatively low and have seen small yield increases relative to those of cereals ( [[#Foyer--2016|Foyer et al. 2016]] ; [[#McDermott--2017|McDermott and Wyatt 2017]] ; [[#Barbieri--2021|Barbieri et al. 2021]] ; [[#Semba--2021|Semba et al. 2021]] ).

'''Technological innovations:''' have made food production more efficient since the onset of agriculture ( [[#Winiwarter--2014|Winiwarter et al. 2014]] ; [[#Herrero--2020|Herrero et al. 2020]] ). Emerging technologies include digital agriculture (using advanced sensors, big data), gene technology (crop bio-fortification, genome editing, crop innovations), sustainable intensification (automation of processes, improved inputs, precision agriculture) ( [[#Herrero--2020|Herrero et al. 2020]] ), or multi-trophic aquaculture approaches ( [[#Knowler--2020|Knowler et al. 2020]] ; [[#Sanz-Lazaro--2020|Sanz-Lazaro and Sanchez-Jerez 2020]] ), though literature on aquaculture and fisheries in the context of GHG mitigation is limited.

Such technologies may contribute to a reduction of GHG emissions at the food system level, enhanced provision of food, better consideration of ecosystem services, and/or contribute to nutrition-sensitive agriculture, for example, by increasing the nutritional quality of staple crops, increasing the palatability of leguminous crops such as lupines, or increasing the agronomic efficiency or resilience of crops with good nutritional characteristics.

For details on agricultural mitigation opportunities refer to [[IPCC:Wg3:Chapter:Chapter-7#7.4|Section 7.4]] .

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==== 12.4.3.1 Controlled-environment Agriculture ====

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Controlled-environment agriculture is mainly based on hydroponic or aquaponic cultivation systems that do not require soil. Aquaponics combine hydroponics with a re-circulating aquaculture compartment for integrated production of plants and fish ( [[#Junge--2017|Junge et al. 2017]] ; [[#Maucieri--2018|Maucieri et al. 2018]] ), while aeroponics is a further development of hydroponics that replaces water as a growing medium with a mist of nutrient solution ( [[#Al-Kodmany--2018|Al-Kodmany 2018]] ). Aquaponics could potentially produce proteins in urban farms, but the technology is not yet mature and its economic and environmental performance is unclear ( [[#Love--2015|Love et al. 2015]] ; [[#O’Sullivan--2019|O’Sullivan et al. 2019]] ).

Controlled-environment agriculture is often undertaken in urban environments to take advantage of short supply chains ( [[#O’Sullivan--2019|O’Sullivan et al. 2019]] ), and might use abandoned buildings or be integrated in supermarkets, producing for example herbs ‘on demand’.

Optimising growing conditions, hydroponic systems achieve higher yields than un-conditioned agriculture ( [[#O’Sullivan--2019|O’Sullivan et al. 2019]] ); and yields can be further enhanced in CO 2 -enriched atmospheres ( [[#Shamshiri--2018|Shamshiri et al. 2018]] ; [[#Armanda--2019|Armanda et al. 2019]] ). By using existing spaces or modular systems that can be vertically stacked, this technology minimises land demand, however it is energy intensive and requires large financial investments. So far, only a few crops are commercially produced in vertical farms, including lettuce and other leafy greens, herbs and some vegetables, due to their short growth period and high value ( [[#Benke--2017|Benke and Tomkins 2017]] ; [[#Armanda--2019|Armanda et al. 2019]] ; [[#Beacham--2019|Beacham et al. 2019]] ; [[#O’Sullivan--2019|O’Sullivan et al. 2019]] ). Through breeding, other crops could reach commercial feasibility, or crops with improved taste or nutritional characteristics can be grown ( [[#O’Sullivan--2019|O’Sullivan et al. 2019]] ).

In controlled-environment agriculture, photosynthesis is fuelled by artificial light through LEDs or a combination of natural light with LEDs. Control of the wave band and light cycle of the LEDs and micro-climate can be used to optimise photosynthetic activity, yield and crop quality ( [[#Gómez--2018|Gómez and Gennaro Izzo 2018]] ; [[#Shamshiri--2018|Shamshiri et al. 2018]] ).

Co-benefits of controlled-environment agriculture include minimising water and nutrient losses as well as agro-chemical use ( [[#Al-Kodmany--2018|Al-Kodmany 2018]] ; [[#Shamshiri--2018|Shamshiri et al. 2018]] ; [[#Armanda--2019|Armanda et al. 2019]] ; [[#Farfan--2019|Farfan et al. 2019]] ; [[#O’Sullivan--2019|O’Sullivan et al. 2019]] ; [[#Rufí-Salís--2020|Rufí-Salís et al. 2020]] ) ( ''robust evidence, high agreement'' ). Water is recycled in a closed system and additionally some plants generate fresh water by evaporation from grey or black water, and high nutrient use efficiencies are possible. Food production from controlled-environment agriculture is independent of weather conditions and able to satisfy some consumer demand for locally-produced fresh and diverse produce throughout the year ( [[#Benke--2017|Benke and Tomkins 2017]] ; [[#Al-Kodmany--2018|Al-Kodmany 2018]] ; [[#O’Sullivan--2019|O’Sullivan et al. 2019]] ).

Controlled-environment agriculture is a very energy intensive technology (mainly for cooling) and its GHG intensity depends therefore crucially on the source of the energy. Options for reducing GHG intensity include reducing energy use through improved lighting and cooling efficiency or by employing low-carbon energy sources, potentially integrated into the building structure ( [[#Benke--2017|Benke and Tomkins 2017]] ).

Comprehensive studies assessing the GHG balance of controlled-environment agriculture are lacking. The overall GHG emissions from controlled-environment agriculture is therefore uncertain and depends on the balance of reduced GHG emissions from production and distribution and reduced land requirements, versus increased external energy needs.

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<span id="emerging-foods-and-production-technologies"></span>
==== 12.4.3.2 Emerging Foods and Production Technologies ====

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A diverse range of novel food products and production systems are emerging, that are proposed to reduce GHG emissions from food production, mainly by replacing conventional animal-source food with alternative protein sources. Assessments of the potential of dietary changes are given in Sections 5.3 and 7.4. Here, we assess the GHG intensities of emerging food production technologies. This includes products such as insects, algae, mussels and products from bio-refineries, some of which have been consumed in certain societies and/or in smaller quantities ( [[#Pikaar--2018|Pikaar et al. 2018]] ; [[#Jönsson--2019|Jönsson et al. 2019]] ; [[#Govorushko--2019|Govorushko 2019]] ; [[#Raheem--2019a|Raheem et al. 2019a]] ; [[#Souza%20Filho--2019|Souza Filho et al. 2019]] ). The novel aspect considered here is the scale at which they are proposed to replace conventional food with the aim to reduce both negative health and environmental impacts. To fully realise the health benefits, dietary shifts should also encompass a reduction in consumption of added sugars, salt, saturated fats, and potentially harmful additives ( [[#Curtain--2019|Curtain and Grafenauer 2019]] ; [[#Fardet--2019|Fardet and Rock 2019]] ; [[#Petersen--2021|Petersen et al. 2021]] ).

Meat analogues have attracted substantial venture capital, and production costs have dropped considerably in the last decade, with some reaching market maturity ( [[#Mouat--2018|Mouat and Prince 2018]] ; [[#Santo--2020|Santo et al. 2020]] ), but there is uncertainty whether they will ‘disrupt’ the food market or remain niche products. According to [[#Kumar--2017|Kumar et al. (2017)]] , the demand for plant-based meat analogues is expected to increase as their production is relatively cheap and they satisfy consumer demands with regard to health and environmental concerns as well as ethical and religious requirements. Consumer acceptance is still low for some options, especially insects ( [[#Aiking--2019|Aiking and de Boer 2019]] ) and cultured meat ( [[#Chriki--2020|Chriki and Hocquette 2020]] ; [[#Siegrist--2020|Siegrist and Hartmann 2020]] ).

'''Insects:''' Farmed edible insects have a higher feed conversion ratio than other animals farmed for food, and have short reproduction periods with high biomass production rates ( [[#Halloran--2016|Halloran et al. 2016]] ). Insects have good nutritional qualities ( [[#Parodi--2018|Parodi et al. 2018]] ). They are suited as a protein source for both humans and livestock, with high protein content and favourable fatty acid composition ( [[#Fasolin--2019|Fasolin et al. 2019]] ; [[#Raheem--2019b|Raheem et al. 2019b]] ). If used as feed, they can grow on food waste and manure; if used as food, food safety concerns and regulations can restrict the use of manure ( [[#Raheem--2019b|Raheem et al. 2019b]] ) or food waste ( [[#Varelas--2019|Varelas 2019]] ) as growing substrates, and the dangers of pathogenic or toxigenic microorganisms and incidences of anti-microbial resistance need to be managed ( [[#Garofalo--2019|Garofalo et al. 2019]] ).

'''Algae and bivalves''' have a high protein content and a favourable nutrient profile and can play a role in providing sustainable food. Bivalves are high in omega-3 fatty acids and vitamin B12 and therefore well suited as replacement of conventional meats, and have a lower GHG footprint ( [[#Parodi--2018|Parodi et al. 2018]] ; [[#Willer--2020|Willer and Aldridge 2020]] ). Micro- and macro algae are rich in omega-3 and omega-6 fatty acids, anti-oxidants and vitamins ( [[#Parodi--2018|Parodi et al. 2018]] ; [[#Peñalver--2020|Peñalver et al. 2020]] ; [[#Torres-Tiji--2020|Torres-Tiji et al. 2020]] ). [[#Kim--2019|Kim et al. (2019)]] show that diets with modest amounts of animals low on the food chain such as forage fish, bivalves, or insects have similar GHG intensities to vegan diets. Algae and bi-valves can be used to filter nutrients from waters, though care is required to avoid accumulation of hazardous substances ( [[#Gentry--2020|Gentry et al. 2020]] ; [[#Willer--2020|Willer and Aldridge 2020]] ).

'''Plant-based meat, milk and egg analogues:''' Demand for plant-based proteins is increasing and incentivising the development of protein crop varieties with improved agronomic performance and/or nutritional quality ( [[#Santo--2020|Santo et al. 2020]] ). There is also an emerging market for meat replacements based on plant proteins, such as pulses, cereals, soya, algae and other ingredients mainly used to imitate the taste, texture and nutritional profiles of animal-source food ( [[#Kumar--2017|Kumar et al. 2017]] ; [[#Boukid--2021|Boukid 2021]] ). Currently, the majority of plant-based meat analogues is based on soy ( [[#Semba--2021|Semba et al. 2021]] ). While other products still serve a niche market, their share is growing rapidly and some studies project a sizeable share within a decade ( [[#Kumar--2017|Kumar et al. 2017]] ; [[#Jönsson--2019|Jönsson et al. 2019]] ). In particular, plant-based milk alternatives have seen large increases in market share ( [[#Jönsson--2019|Jönsson et al. 2019]] ). A LCA of 56 plant-based meat analogues showed mean GHG intensities (farm to factory) of 0.21–0.23 kgCO 2 -eq per 100 g of product or 20 g of protein for all assessed protein sources ( [[#Fresán--2019|Fresán et al. 2019]] ). Higher footprints were found in the meta-review by [[#Santo--2020|Santo et al. (2020)]] . Including preparation, Meija et al. (2019) found higher emissions for burgers and sausages as compared to minced products.

'''Cellular agriculture:''' The use of fungi, algae and bacteria is an old process (beer, bread, yoghurt) and serves, among others, for the preservation of products. The concept of cellular agriculture ( [[#Mattick--2018|Mattick 2018]] ) covers bio-technological processes that use micro-organisms to produce acellular (fermentation-based cellular agriculture) or cellular products. Yeasts, fungi or bacteria can synthesise acellular products such as haem, milk and egg proteins, or protein-rich animal feed, other food ingredients, and pharmaceutical and material products ( [[#Rischer--2020|Rischer et al. 2020]] ; [[#Mendly-Zambo--2021|Mendly-Zambo et al. 2021]] ). Cellular products include cell tissues such as muscle cells to grow cultured meat, fish or other cells ( [[#Post--2012|Post 2012]] ; [[#Rischer--2020|Rischer et al. 2020]] ) and products where the micro-organisms will be eaten themselves ( [[#Pikaar--2018|Pikaar et al. 2018]] ; [[#Sillman--2019|Sillman et al. 2019]] ; [[#Schade--2020|Schade et al. 2020]] ). Single cell proteins, combined with photovoltaic electricity generation and direct air capture of carbon dioxide, are proposed as highly land- and energy-efficient alternatives to plant-based protein ( [[#Leger--2021|Leger et al. 2021]] ). Some microbial proteins are produced in a ‘bioreactor’ and use Haber-Bosch nitrogen and vegetable sugars or atmospheric CO 2 as source of nitrogen and carbon ( [[#Pikaar--2018|Pikaar et al. 2018]] ; [[#Simsa--2019|Simsa et al. 2019]] ). Cultured meat is currently at the research stage and some challenges remain, such as the need for animal-based ingredients to ensure fast and effective growth of muscle cells; tissue engineering to create different meat products; production at scale and at competitive costs; and regulatory barriers ( [[#Post--2012|Post 2012]] ; [[#Stephens--2018|Stephens et al. 2018]] ; [[#Rubio--2019|Rubio et al. 2019]] ; [[#Tuomisto--2019|Tuomisto 2019]] ; [[#Post--2020|Post et al. 2020]] ). Only a few studies to date have quantified the GHG emissions of microbial proteins or cultured meat, suggesting GHG emissions at the level of poultry meat ( [[#Tuomisto--2011|Tuomisto and Teixeira de Mattos 2011]] ; [[#Mattick--2015|Mattick et al. 2015]] ; [[#Souza%20Filho--2019|Souza Filho et al. 2019]] ; [[#Tuomisto--2019|Tuomisto 2019]] ).

A review of LCA studies on different plant-based, animal source and nine ‘future food’ protein sources ( [[#Parodi--2018|Parodi et al. 2018]] ) concluded that insects, macro-algae, mussels, mycoproteins and cultured meat show similar GHG intensities per unit of protein (mean values ranging 0.3–3.1 kgCO 2 -eq per 100 g protein), comparable to milk, eggs, and tuna (mean values ranging 1.2–5.4 kgCO 2 -eq per 100 g protein); while ''chlorella'' and ''spirulina'' consume more energy per unit of protein and were associated with higher GHG emissions (mean values ranging 11–13 kgCO 2 -eq per 100 g protein). As the main source of GHG emissions from insects and cellular agriculture foods is energy consumption, their GHG intensity improves with increased use of low-carbon energy ( [[#Smetana--2015|Smetana et al. 2015]] ; [[#Parodi--2018|Parodi et al. 2018]] ; [[#Pikaar--2018|Pikaar et al. 2018]] ).

Future foods offer other benefits such as lower land requirements, controlled systems with reduced losses of water and nutrients, increased resilience, and possibly reduced hazards from pesticide and antibiotics use and zoonotic diseases, although more research is needed including on allergenic and other safety aspects, and possibly reduced protein bioavailability ( [[#Alexander--2017|Alexander et al. 2017]] ; [[#Parodi--2018|Parodi et al. 2018]] ; [[#Stephens--2018|Stephens et al. 2018]] ; [[#Fasolin--2019|Fasolin et al. 2019]] ; [[#Chriki--2020|Chriki and Hocquette 2020]] ; [[#Santo--2020|Santo et al. 2020]] ; [[#Hadi--2021|Hadi and Brightwell 2021]] ; [[#Tzachor--2021|Tzachor et al. 2021]] ) ( ''medium evidence, high agreement'' ). Research is needed also on the effect of processing ( [[#Wickramasinghe--2021|Wickramasinghe et al. 2021]] ), though a randomised crossover trial comparing appetising plant foods with meat alternatives found several beneficial and no adverse effects from the consumption of the plant-based meats (Crimarco et al. 2020).

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==== 12.4.3.3 Food Processing and Packaging ====

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Food processing includes preparation and preservation of fresh commodities (fruit and vegetables, meat, seafood and dairy products), grain milling, production of baked goods, and manufacture of pre-prepared foods and meals. Food processors range from small local operations to large multinational food producers, producing food for local to global markets. The importance of food processing and preservation is particularly evident in developing countries which lack cold chains for the preservation and distribution of fresh perishable products such as fresh fish ( [[#Adeyeye--2016|Adeyeye and Oyewole 2016]] ; [[#Adeyeye--2017|Adeyeye 2017]] ).

Mitigation in food processing largely focuses on reducing food waste and fossil energy usage during the processing itself, as well as in the transport, packaging and storage of food products for distribution and sale ( [[#Silva--2019|Silva and Sanjuán 2019]] ). Reducing food waste provides emissions savings by reducing wastage of primary inputs required for food production. Another mitigation route, contributing to the circular bioeconomy ( [[#12.6.1.2|Section 12.6.1.2]] and Cross-Working Group Box 3 in this chapter), is by valorisation of food processing by-products through recovery of nutrients and/or energy. No global analyses of the emissions savings potential from the processing step in the value chain could be found.

Reduced food waste during food processing can be achieved by seeking alternative processing routes ( [[#Atuonwu--2018|Atuonwu et al. 2018]] ), improved communication along the food value chain ( [[#Göbel--2015|Göbel et al. 2015]] ), optimisation of food processing facilities, reducing contamination, and limiting damages and spillage ( [[#HLPE--2014|HLPE 2014]] ). Optimisation of food packaging also plays an important role in reducing food waste, in that it can extend product shelf life; protect against damage during transport and handling; prevent spoilage; facilitate easy opening and emptying; and communicate storage and preparation information to consumers ( [[#Molina-Besch--2019|Molina-Besch et al. 2019]] ).

Developments in smart packaging are increasingly contributing to reducing food waste along the food value chain. Strategies for reducing the environmental impact of packaging include using less, and more sustainable, materials and a shift to reusable packaging ( [[#Coelho--2020|Coelho et al. 2020]] ). Active packaging increases shelf life through regulating the environment inside the packaging, including levels of oxygen, moisture and chemicals released as the food ages ( [[#Emanuel--2019|Emanuel and Sandhu 2019]] ). Intelligent packaging communicates information on the freshness of the food through indicator labels ( [[#Poyatos-Racionero--2018|Poyatos-Racionero et al. 2018]] ), and data carriers can store information on conditions such as temperature along the entire food chain ( [[#Müller--2019|Müller and Schmid 2019]] ).

LCA can be used to evaluate the benefits and trade-offs associated with different processing or packaging types ( [[#Silva--2019|Silva and Sanjuán 2019]] ). Some options, such as aluminium, steel and glass, require high energy investment in manufacture when produced from primary materials, with significant savings in energy through recycling being possible ( [[#Camaratta--2020|Camaratta et al. 2020]] ). However, these materials are inert in landfill. Other packaging options, such as paper and biodegradable packaging, may require a lower energy investment during manufacture, but may require larger land area and can release methane when consigned to anaerobic landfill where there is no methane recovery. Nevertheless, packaging accounts for only 1–12% (typically around 5%) of the GHG emissions in the lifecycle of a food system ( [[#Wohner--2019|Wohner et al. 2019]] ; [[#Crippa--2021b|Crippa et al. 2021b]] ), suggesting that its benefits can often outweigh the emissions associated with the packaging itself.

The second component of mitigation in food processing relates to reduction in fossil energy use. Opportunities include energy efficiency in processes (also discussed in [[IPCC:Wg3:Chapter:Chapter-11#11.3|Section 11.3]] ), the use of heat and electricity from low-carbon energy sources in processing (Chapter 6), through off-grid thermal processing (sun drying, food smoking) and improving logistics efficiencies. Energy-intensive processes with energy-saving potential include milling and refining (oil seeds, corn, sugar), drying, and food safety practices such as sterilisation and pasteurisation ( [[#Niles--2018|Niles et al. 2018]] ). Packaging also plays a role: reduced transport energy can be achieved through reducing the mass of goods transported and improving packing densities in transport vehicles ( [[#Lindh--2016|Lindh et al. 2016]] ; [[#Molina-Besch--2019|Molina-Besch et al. 2019]] ; [[#Wohner--2019|Wohner et al. 2019]] ). Choice of packaging also influences refrigeration energy requirements during transport and storage.

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<span id="storage-and-distribution"></span>
==== 12.4.3.4 Storage and Distribution ====

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Transport mitigation options along the supply chain include improved logistics, the use of alternative fuels and transport modes, and reduced transport distances. Logistics and alternative fuels and transport modes are discussed in Chapter 10. Transport emissions might increase with increasing demand for a diversity of foods as developing countries become more affluent. New technologies that enable food on demand or online food shopping systems might further increase emissions from food transport; however, the consequences are uncertain and might also entail a shift from individual traffic to bulk transport. The impact on food waste is also uncertain as more targeted delivery options could reduce food waste, but easier access to a wider range of food could also foster over-supply and increase food waste. Mitigation opportunities in food transport are inherently linked to decarbonisation of the transport sector (Chapter 10).

Retail and the food service industry are the main factors shaping the external food environment or ‘food entry points’; they are the ‘physical spaces where food is obtained; the built environment that allows consumers to access these spaces’ ( [[#HLPE--2017|HLPE 2017]] ). These industries have significant influence on consumers’ choices and can play a role in reducing GHG emissions from food systems. Opportunities are available for optimisation of inventories in response to consumer demands through advanced IT systems ( [[#Niles--2018|Niles et al. 2018]] ), and for discounting foods close to sell-by dates, which can serve to reduce both food spoilage and wastage ( [[#Buisman--2019|Buisman et al. 2019]] ).

As one of the highest contributors to energy demand at this stage in the food value chain, refrigeration has received a strong focus in mitigation. Efficient refrigeration options include advanced refrigeration temperature control systems, and installation of more efficient refrigerators, air curtains and closed display fridges ( [[#Chaomuang--2017|Chaomuang et al. 2017]] ). Also related to reducing emissions from cooling and refrigeration is the replacement of hydrofluorocarbons which have very high GWPs with lower GWP alternatives ( [[#Niles--2018|Niles et al. 2018]] ). The use of propane, isobutane, ammonia, hydrofluoroolefins and CO 2 (refrigerant R744) are among those that are being explored, with varying success ( [[#McLinden--2017|McLinden et al. 2017]] ). In recent years, due to restrictions on high GWP-refrigerants, a considerable growth in the market availability of appliances and systems with non-fluorinated refrigerants has been seen ( [[#Eckert--2021|Eckert et al. 2021]] ).

Energy efficiency alternatives generic to buildings more broadly are also relevant here, including efficient lighting, heating, ventilation, and air conditioning systems and building management, with ventilation being a particularly high energy user in retail, that warrants attention ( [[#Kolokotroni--2015|Kolokotroni et al. 2015]] ).

In developing countries particularly, better infrastructure for transportation and expansion of processing and manufacturing industries can significantly reduce food losses, particularly of highly perishable food ( [[#Niles--2018|Niles et al. 2018]] ; [[#FAO--2019a|]] [[#FAO--2019|FAO 2019]] a ).

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