Editing IPCC:AR6/WGIII/Chapter-3 (section)

=== 3.7.1 Synthesis Findings on Mitigation and Sustainable Development ===

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Rapid and effective climate mitigation is a necessary part of sustainable development ( ''high confidence'' ) (Cross-Chapter Box 5 in Chapter 4), but the latter can only be realised if climate mitigation becomes integrated with sustainable development policies ( ''high confidence'' ). Targeted policy areas must include healthy nutrition, sustainable consumption and production, inequality and poverty alleviation, air quality and international collaboration ( ''high confidence'' ) ''.'' Lower energy demand enables synergies between mitigation and sustainability, with lower reliance on CDR ( ''hi'' ''gh confidence'' ).

This section covers the long-term interconnection of sustainable development and mitigation, taking forward the holistic vision of sustainable development described in the SDGs ( [[#Brandi--2015|Brandi 2015]] ; [[#Leal%20Filho--2018|Leal Filho et al. 2018]] ). Recent studies have explored the aggregated impact of mitigation for multiple sustainable-development dimensions ( [[#Hasegawa--2014|Hasegawa et al. 2014]] ; [[#Bertram--2018|Bertram et al. 2018]] ; [[#Fuso%20Nerini--2018|Fuso Nerini et al. 2018]] ; [[#Grubler--2018|Grubler et al. 2018]] ; [[#McCollum--2018b|McCollum et al. 2018b]] ; [[#Soergel--2021a|Soergel et al. 2021a]] ; [[#van%20Vuuren--2019|van Vuuren et al. 2019]] ). For instance, Figure 3.38 shows selected mitigation co-benefits and trade-offs based on a subset of models and scenarios, since so far many IAMs do not have a comprehensive coverage of SDGs ( [[#Rao--2017a|Rao et al. 2017a]] ; [[#van%20Soest--2019|van Soest et al. 2019]] ). Figure 3.38 shows that mitigation ''likely'' leads to increased forest cover (SDG 15 – life on land) and reduced mortality from ambient PM2.5 pollution (SDG 3 – good health and well-being) compared to reference scenarios. However, mitigation policies can also cause higher food prices and an increased population at risk of hunger (SDG 2 – zero hunger) and relying on solid fuels (SDG 3 – good health and well-being; and SDG 7 – affordable and clean energy) as side effects. These trade-offs can be compensated through targeted support measures and/or additional sustainable development policies ( [[#Cameron--2016|Cameron et al. 2016]] ; [[#Bertram--2018|Bertram et al. 2018]] ; [[#Fujimori--2019|Fujimori et al. 2019]] ; [[#Soergel--2021a|Soergel et al. 2021a]] ).

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[[File:4707b7df94af4f48037fc279cb912ab4 IPCC_AR6_WGIII_Figure_3_38.png]]

'''Figure 3.38 | Effect of climate change mitigation on different dimensions of sustainable development: shown are mitigation scenarios compatible with the 1.''' '''5°C target (blue) and reference scenarios (yellow).''' Blue box plots contain scenarios that include narrow mitigation policies from different studies (see below). This is compared to a sustainable development scenario ( ''SP'' , [[#Soergel--2021a|Soergel et al. (2021a)]] , grey diamonds) integrating mitigation and SD policies (e.g., zero hunger in 2050 by assumption). Scenario sources for box plots: single scenarios from: (i) [[#Fujimori--2020a|Fujimori et al. (2020a)]] ; (ii) [[#Soergel--2021a|Soergel et al. (2021a)]] ; multi-model scenario set from CD-LINKS ( [[#McCollum--2018b|McCollum et al. 2018b]] ; [[#Fujimori--2019|Fujimori et al. 2019]] ; [[#Roelfsema--2020|Roelfsema et al. 2020]] ). For associated methods, see also [[#Cameron--2016|Cameron et al. (2016)]] and [[#Rafaj--2021|Rafaj et al. (2021)]] . The reference scenario for [[#Fujimori--2020a|Fujimori et al. (2020a)]] is no-policy baseline; for all other studies, it includes current climate policies. In the ‘Food prices’ and ‘Risk of hunger’ panels, scenarios from CD-LINKS include a price cap of USD200 tCO 2 -eq for land-use emissions ( [[#Fujimori--2019|Fujimori et al. 2019]] ). For the other indicators, CD-LINKS scenarios without price cap ( [[#Roelfsema--2020|Roelfsema et al. 2020]] ) are used due to SDG indicator availability. In the ‘Premature deaths’ panel, a well-below 2°C scenario from [[#Fujimori--2020a|Fujimori et al. (2020a)]] is used in place of a 1.5°C scenario due to data availability, and all scenarios are indexed to their 2015 values due to a spread in reported levels between models. SDG icons were created by the United Nations.

The synthesis of the interplay between climate mitigation and sustainable development is shown in Figure 3.39. Panel a shows the reduction in population affected by climate impacts at 1.5°C compared to 3°C according to sustainability domains ( [[#Byers--2018|Byers et al. 2018]] ). Reducing warming reduces the population impacted by all impact categories shown ( ''high confidence'' ). The left panel does not take into account any side effects of mitigation efforts or policies to reduce warming: only reductions in climate impacts. This underscores that mitigation is an integral basis for comprehensive sustainable development ( [[#Watts--2015|Watts et al. 2015]] ).

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[[File:e66d4afcbb1e566f138249b15c2e8cab IPCC_AR6_WGIII_Figure_3_39.png]]

'''Figure 3.39 | Sustainable development effects of mitigation to 1.''' '''5°C. Panel (a):''' benefits of mitigation from avoided impacts. '''Panel (b):''' sustainability co-benefits and trade-offs of narrow mitigation policies (averaged over multiple models). '''Panel (c):''' sustainability co-benefits and trade-offs of mitigation policies integrating Sustainable Development Goals. Scale: 0% means no change compared to 3°C (left) or current policies (middle and right). Blue values correspond to proportional improvements, red values to proportional worsening. Note: only the left panel considers climate impacts on sustainable development; the middle and right panels do not. ‘Res’ C&amp;P’ stands for Responsible Consumption and Production (SDG 12). Data are from [[#Byers--2018|Byers et al. (2018)]] (left), ''SP'' / [[#Soergel--2021a|Soergel et al. (2021a)]] (right). Methods used in middle panel: for biodiversity, [[#Ohashi--2019|Ohashi et al. (2019)]] ; for ecotoxicity and eutrophication, [[#Arvesen--2018|Arvesen et al. (2018)]] and [[#Pehl--2017|Pehl et al. (2017)]] ; for energy access, [[#Cameron--2016|Cameron et al. (2016)]] . ‘Energy services’ on the right is a measure of useful energy in buildings and transport. ‘Food prices’ and ‘Risk of hunger’ in the middle panel are the same as in Figure 3.38.

Panels b and c of Figure 3.39 show the effects of 1.5°C mitigation policies compared to current national policies: narrow mitigation policies (averaged over several models, middle panel), and policies integrating sustainability considerations (right panel of Figure 3.39, based on the Illustrative Mitigation Pathway ‘Shifting Pathways’ ( IMP-SP ) ( [[#Soergel--2021a|Soergel et al. 2021a]] )). Note that neither middle nor right panels include climate impacts.

Areas of co-benefits include human health, ambient air pollution and other specific kinds of pollution, while areas of trade-off include food access, habitat loss and mineral resources ( ''medium confidence'' ). For example, action consistent with 1.5°C in the absence of energy-demand reduction measures require large quantities of CDR, which, depending on the type used, are likely to negatively impact both food availability and areas for biodiversity ( [[#Fujimori--2018|Fujimori et al. 2018]] ; [[#Ohashi--2019|Ohashi et al. 2019]] ; [[#Roelfsema--2020|Roelfsema et al. 2020]] ).

Mitigation to 1.5°C reduces climate impacts on sustainability (left). Policies integrating sustainability and mitigation (right) have far fewer trade-offs than narrow mitigation policies (middle).

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==== 3.7.1.1 Policies Combining Mitigation and Sustainable Development ====

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These findings indicate that holistic policymaking integrating sustainability objectives alongside mitigation will be important in attaining Sustainable Development Goals ( [[#van%20Vuuren--2015|van Vuuren et al. 2015]] , 2018; [[#Bertram--2018|Bertram et al. 2018]] ; [[#Fujimori--2018|Fujimori et al. 2018]] ; [[#Hasegawa--2018|Hasegawa et al. 2018]] ; [[#Liu--2020a|Liu et al. 2020a]] ; [[#Honegger--2021|Honegger et al. 2021]] ; [[#Soergel--2021a|Soergel et al. 2021a]] ). Mitigation policies which target direct sector-level regulation, early mitigation action, and lifestyle changes have beneficial sustainable development outcomes across air pollution, food, energy and water ( [[#Bertram--2018|Bertram et al. 2018]] ).

These policies include ones around stringent air quality ( [[#Kinney--2018|Kinney 2018]] ; [[#Rafaj--2018|Rafaj et al. 2018]] ; [[#Soergel--2021a|Soergel et al. 2021a]] ); efficient and safe demand-side technologies, especially cook stoves ( [[#Cameron--2016|Cameron et al. 2016]] ); lifestyle changes ( [[#Bertram--2018|Bertram et al. 2018]] ; [[#Grubler--2018|Grubler et al. 2018]] ; [[#Soergel--2021a|Soergel et al. 2021a]] ); industrial and sectoral policy ( [[#Bertram--2018|Bertram et al. 2018]] ); agricultural and food policies (including food waste) ( [[#van%20Vuuren--2019|van Vuuren et al. 2019]] ; [[#Soergel--2021a|Soergel et al. 2021a]] ); international cooperation ( [[#Soergel--2021a|Soergel et al. 2021a]] ); as well as economic policies described in [[#3.6|Section 3.6]] . Recent research shows that mitigation is compatible with reductions in inequality and poverty (Box 3.6).

Lower demand – for example, for energy and land-intensive consumption such as meat – represents a synergistic strategy for achieving ambitious climate mitigation without compromising Sustainable Development Goals ( ''high confidence'' ) ( [[#Bertram--2018|Bertram et al. 2018]] ; [[#Grubler--2018|Grubler et al. 2018]] ; [[#van%20Vuuren--2018|van Vuuren et al. 2018]] ; [[#Kikstra--2021b|Kikstra et al. 2021b]] ; [[#Soergel--2021a|Soergel et al. 2021a]] ). This is especially true for reliance on BECCS ( [[#Hickel--2021|Hickel et al. 2021]] ; [[#Keyßer--2021|Keyßer and Lenzen 2021]] ). Options that reduce agricultural demand (e.g., dietary change, reduced food waste) can have co-benefits for adaptation through reductions in demand for land and water ( [[#Bertram--2018|Bertram et al. 2018]] ; [[#Grubler--2018|Grubler et al. 2018]] ; [[#IPCC--2019a|IPCC 2019a]] ; [[#Soergel--2021a|Soergel et al. 2021a]] ).

While the impacts of climate change on agricultural output are expected to increase the population at risk of hunger, there is evidence suggesting population growth will be the dominant driver of hunger and undernourishment in Africa in 2050 ( [[#Hall--2017|Hall et al. 2017]] ). Meeting SDG 5, relating to gender equality and reproductive rights, could substantially lower population growth, leading to a global population lower than the 95% prediction range of the UN projections (Abel et al. 2016). Meeting SDG 5 (gender equality, including via voluntary family planning ( [[#O’Sullivan--2018|O’Sullivan 2018]] )) could thus minimise the risks to SDG 2 (zero hunger) that are posed by meeting SDG 13 (climate action).

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