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

== 3.7 Enable Development, Mitigation and Avoided Impacts ==

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=== 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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=== Box 3.6 | Poverty and Inequality ===

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There is high confidence ( ''medium evidence'' , ''high agreement'' ) that the eradication of extreme poverty and universal access to energy can be achieved without resulting in significant GHG emissions ( [[#Tait--2012|Tait and Winkler 2012]] ; [[#Chakravarty--2013|Chakravarty and Tavoni 2013]] ; [[#Pachauri--2013|Pachauri et al. 2013]] ; [[#Pachauri--2014|Pachauri 2014]] ; [[#Rao--2014|Rao 2014]] ; [[#Hubacek--2017b|Hubacek et al. 2017b]] ; [[#Poblete-Cazenave--2021|Poblete-Cazenave et al. 2021]] ). There is also high agreement in the literature that a focus on well-being and decent living standards for all can reduce disparities in access to basic needs for services concurrently with climate mitigation ( [[IPCC:Wg3:Chapter:Chapter-5#5.2|Section 5.2]] ). Mitigation pathways in which national redistribution of carbon-pricing revenues is combined with international climate finance, achieve poverty reduction globally ( [[#Fujimori--2020b|Fujimori et al. 2020b]] ; [[#Soergel--2021b|Soergel et al. 2021b]] ). Carbon-pricing revenues in mitigation pathways consistent with limiting temperature increase to 2°C could also contribute to finance investment needs for basic infrastructure ( [[#Jakob--2016|Jakob et al. 2016]] ) and the achievement of the SDGs ( [[#Franks--2018|Franks et al. 2018]] ).

Several studies conclude that reaching higher income levels globally, beyond exiting extreme poverty, and achieving more qualitative social objectives and well-being, are associated with higher emissions ( [[#Ribas--2017|Ribas et al. 2017]] , 2019; [[#Hubacek--2017b|Hubacek et al. 2017b]] ; [[#Fischetti--2018|Fischetti 2018]] ; [[#Scherer--2018|Scherer et al. 2018]] ). Studies give divergent results on the effect of economic inequality reduction on emissions, with either an increase or a decrease in emissions ( [[#Berthe--2015|Berthe and Elie 2015]] ; [[#Lamb--2015|Lamb and Rao 2015]] ; [[#Grunewald--2017|Grunewald et al. 2017]] ; [[#Hubacek--2017a|Hubacek et al. 2017a]] ,b; [[#Jorgenson--2017|Jorgenson et al. 2017]] ; [[#Knight--2017|Knight et al. 2017]] ; [[#Mader--2018|Mader 2018]] ; [[#Rao--2018|Rao and Min 2018]] ; [[#Liu--2019|Liu et al. 2019]] ; [[#Sager--2019|Sager 2019]] ; [[#Baležentis--2020|Baležentis et al. 2020]] ; [[#Liobikienė--2020|Liobikienė 2020]] ; [[#Liobikienė--2020|Liobikienė and Rimkuvienė 2020]] ; [[#Liu--2020b|Liu et al. 2020b]] ; [[#Millward-Hopkins--2021|Millward-Hopkins and Oswald 2021]] ). However, the absolute effect of economic inequality reduction on emissions remains moderate, under the assumptions tested. For instance, [[#Sager--2019|Sager (2019)]] finds that a full redistribution of income leading to equality among US households in a counterfactual scenario for 2009 would raise emissions by 2.3%; and [[#Rao--2018|Rao and Min (2018)]] limit to 8% the maximum plausible increase in emissions that would accompany the reduction of the global Gini coefficient from its current level of 0.55 to a level of 0.3 by 2050. Similarly, reduced income inequality would lead to a global energy-demand increase of 7% ( [[#Oswald--2021|Oswald et al. 2021]] ). Reconciling mitigation and inequality reduction objectives requires policies that take into account both objectives at all stages of policymaking ( [[#Markkanen--2019|Markkanen and Anger-Kraavi 2019]] ), including focusing on the carbon intensity of lifestyles ( [[#Scherer--2018|Scherer et al. 2018]] ), attention to sufficiency and equity ( [[#Fischetti--2018|Fischetti 2018]] ) ''',''' and targeting the consumption of the richest and highest-emitting households ( [[#Otto--2019|Otto et al. 2019]] ).

In modelled mitigation pathways, inequality in per-capita emissions between regions are generally reduced over time, and the reduction is generally more pronounced in lower-temperature pathways (Box 3.6, Figure 1). Already in 2030, if NDCs from the Paris Agreement, announced prior to COP26, are fully achieved, inequalities in per-capita GHG emissions between countries would be reduced ( [[#Benveniste--2018|Benveniste et al. 2018]] ).

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[[File:b3e0dab14ffe7ed8a5d1f64df075b87c IPCC_AR6_WGIII_Box_3_6_Figure_1.png]]

'''Box 3.6, Figure 1 | Difference in per-capita emissions of Kyoto gases between the highest emitting and the lowest emitting of the 10 regions, in 2030 and 2050, by temperature category of pathways.'''

Through avoiding impacts of climate change, which fall more heavily on low-income countries, communities and households, and exacerbate poverty, mitigation reduces inequalities and poverty ( [[#3.6.4.2|Section 3.6.4.2]] ).

The remainder of this section covers specific domains of sustainable development: food ( [[#3.7.2|Section 3.7.2]] ), water ( [[#3.7.3|Section 3.7.3]] ), energy ( [[#3.7.4|Section 3.7.4]] ), health ( [[#3.7.5|Section 3.7.5]] ), biodiversity ( [[#3.7.6|Section 3.7.6]] ) and multi-sector – cities, infrastructure, industry, production and consumption ( [[#3.7.7|Section 3.7.7]] ). These represent the areas with the strongest research connecting mitigation to sustainable development. The links to individual SDGs are given within these sections. Each domain covers the benefits of avoided climate impacts and the implications (synergies and trade-offs) of mitigation efforts.

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=== 3.7.2 Food ===

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The goal of SDG 2 is to achieve ‘zero-hunger’ by 2030. According to the UN (2015), over 25% of the global population currently experience food insecurity and nearly 40% of these experience severe food insecurity, a situation worsened by the COVID-19 pandemic ( [[#Paslakis--2021|Paslakis et al. 2021]] ).

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==== 3.7.2.1 Benefits of Avoided Climate Impacts Along Mitigation Pathways ====

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Climate change will reduce crop yields, increase food insecurity, and negatively influence nutrition and mortality ( ''high confidence'' ) (AR6 WGII Chapter 5). Climate mitigation will thus reduce these impacts, and hence reduce food insecurity ( ''high confidence'' ). The yield reduction of global food production will increase food insecurity and influence nutrition and mortality ( [[#Hasegawa--2014|Hasegawa et al. 2014]] ; [[#Springmann--2016a|Springmann et al. 2016a]] ). For instance, [[#Springmann--2016a|Springmann et al. (2016a)]] estimate that climate change could lead to 315,000–736,000 additional deaths by 2050, though these could mostly be averted by stringent mitigation efforts. Reducing warming reduces the impacts of climate change, including extreme climates, on food production and risk of hunger ( [[#Hasegawa--2014|Hasegawa et al. 2014]] , 2021b).

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==== 3.7.2.2 Implications of Mitigation Efforts Along Pathways ====

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Recent studies explore the effect of climate change mitigation on agricultural markets and food security ( [[#Havlík--2014|Havlík et al. 2014]] ; [[#Hasegawa--2018|Hasegawa et al. 2018]] ; [[#Doelman--2019|Doelman et al. 2019]] ; [[#Fujimori--2019|Fujimori et al. 2019]] ). Mitigation policies aimed at achieving 1.5°C–2°C, if not managed properly, could negatively affect food security through changes in land and food prices ( ''high confidence'' ), leading to increases in the population at risk of hunger by 80–280 million people compared to baseline scenarios. These studies assume uniform carbon prices on AFOLU sectors (with some sectoral caps) and do not account for climate impacts on food production.

Mitigating climate change while ensuring that food security is not adversely affected requires a range of different strategies and interventions ( ''high confidence'' ). [[#Fujimori--2018|Fujimori et al. (2018)]] explore possible economic solutions to these unintended impacts of mitigation (e.g., agricultural subsidies, food aid, and domestic reallocation of income) with an additional small (&lt;0.1%) change in global GDP. Targeted food-security support is needed to shield impoverished and vulnerable people from the risk of hunger that could be caused by the economic effects of policies narrowly focussed on climate objectives. Introducing more biofuels and careful selection of bioenergy feedstocks could also reduce negative impacts (FAO, IFAD, UNICEF, WFP and WHO, 2017). Reconciling bioenergy demands with food and biodiversity, as well as competition for land and water, will require changes in food systems – agricultural intensification, open trade, less consumption of animal products and reduced food losses – and advanced biotechnologies ( [[#Henry--2018|Henry et al. 2018]] ; [[#Xu--2019|Xu et al. 2019]] ).

There are many other synergistic measures for climate mitigation and food security. Agricultural technological innovation can improve the efficiency of land use and food systems, thus reducing the pressure on land from increasing food demand ( [[#Foley--2011|Foley et al. 2011]] ; [[#Popp--2014|Popp et al. 2014]] ; [[#Obersteiner--2016|Obersteiner et al. 2016]] ; [[#Humpenöder--2018|Humpenöder et al. 2018]] ; [[#Doelman--2019|Doelman et al. 2019]] ). Furthermore, decreasing consumption of animal products could contribute to SDG 3.4 by reducing the risk of non-communicable diseases ( [[#Garnett--2016|Garnett 2016]] ).

Taken together, climate changes will reduce crop yields, increase food insecurity and influence nutrition and mortality ( ''high confidence'' ) (see 3.7.2.1). However, if measures are not properly designed, mitigating climate change will also negatively impact on food consumption and security. Additional solutions to negative impacts associated with climate mitigation on food production and consumption include a transition to a sustainable agriculture and food system that is less resource intensive, more resilient to a changing climate, and in line with biodiversity and social targets ( [[#Kayal--2019|Kayal et al. 2019]] ).

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=== 3.7.3 Water ===

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Water isrelevant to SDG 6 (clean water and sanitation), SDG 15 (life on land ), and SDG Targets 12.4 and 3.9 (water pollution and health). This section discusses water quantity, water quality, and water-related extremes. See [[#3.7.5|Section 3.7.5]] for water-related health effects.

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==== 3.7.3.1 Benefits of Avoided Climate Impacts Along Mitigation Pathways ====

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Global precipitation, evapotranspiration, runoff and water availability increase with warming ( [[#Hanasaki--2013|Hanasaki et al. 2013]] ; [[#Greve--2018|Greve et al. 2018]] ) (AR6 WGII Chapter 4). Climate change also affects the occurrence of and exposure to hydrological extremes ( ''high confidence'' ) ( [[#Arnell--2014|Arnell and Lloyd-Hughes 2014]] ; [[#Asadieh--2017|Asadieh and Krakauer 2017]] ; [[#Dottori--2018|Dottori et al. 2018]] ; [[#Naumann--2018|Naumann et al. 2018]] ; [[#IPCC--2019a|IPCC 2019a]] ; [[#Do--2020|Do et al. 2020]] ) (AR6 WGII Chapter 4). Climate models project increases in precipitation intensity ( ''high confidence'' ), local flooding ( ''medium confidence'' ), and drought risk ( ''very high confidence'' ) ( [[#Arnell--2014|Arnell and Lloyd-Hughes 2014]] ; [[#Asadieh--2017|Asadieh and Krakauer 2017]] ; [[#Dottori--2018|Dottori et al. 2018]] ; [[#IPCC--2019a|IPCC 2019a]] ) (AR6 WGII Chapter 4).

The effect of climate change on water availability and hydrological extremes varies by region ( ''high confidence'' ) due to differences in the spatial patterns of projected precipitation changes ( [[#Hanasaki--2013|Hanasaki et al. 2013]] ; [[#Schewe--2014|Schewe et al. 2014]] ; [[#Schlosser--2014|Schlosser et al. 2014]] ; [[#Asadieh--2017|Asadieh and Krakauer 2017]] ; [[#Dottori--2018|Dottori et al. 2018]] ; [[#Naumann--2018|Naumann et al. 2018]] ; [[#Koutroulis--2019|Koutroulis et al. 2019]] ) (AR6 WGII Chapter 4). Global exposure to water stress is projected to increase with increased warming, but increases will not occur in all regions ( [[#Hanasaki--2013|Hanasaki et al. 2013]] ; [[#Schewe--2014|Schewe et al. 2014]] ; [[#Arnell--2014|Arnell and Lloyd-Hughes 2014]] ; [[#Gosling--2016|Gosling and Arnell 2016]] ; [[#IPCC--2019a|IPCC 2019a]] ).

Limiting warming could reduce water-related risks ( ''high confidence'' ) ( [[#O’Neill--2017b|O’Neill et al. 2017b]] ; [[#Byers--2018|Byers et al. 2018]] ; [[#Hurlbert--2019|Hurlbert et al. 2019]] ) (AR6 WGII Chapter 4) and the population exposed to increased water stress ( [[#Hanasaki--2013|Hanasaki et al. 2013]] ; [[#Arnell--2014|Arnell and Lloyd-Hughes 2014]] ; [[#Schewe--2014|Schewe et al. 2014]] ; [[#Gosling--2016|Gosling and Arnell 2016]] ; [[#IPCC--2019a|IPCC 2019a]] ).

The effect of climate change on water depends on the climate model, the hydrological model, and the metric ( ''high confidence'' ) stress [[#Hanasaki--2013|Hanasaki et al. (2013)]] ; [[#Arnell--2014|Arnell and Lloyd-Hughes (2014)]] ; [[#Schewe--2014|Schewe et al. (2014)]] ; [[#Schlosser--2014|Schlosser et al. (2014)]] ; [[#Gosling--2016|Gosling and Arnell (2016)]] ; [[#IPCC--2019a|IPCC (2019a)]] .

However, the effect of socio-economic development could be larger than the effect of climate change ( ''high confidence'' ) ( [[#Arnell--2014|Arnell and Lloyd-Hughes 2014]] ; [[#Schlosser--2014|Schlosser et al. 2014]] ; [[#Graham--2020|Graham et al. 2020]] ).

Climate change can also affect water quality (both thermal and chemical) ( [[#Liu--2017|Liu et al. 2017]] ), leading to increases in stream temperature and nitrogen loading in rivers ( [[#Ballard--2019|Ballard et al. 2019]] ).

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==== 3.7.3.2 Implications of Mitigation Efforts Along Pathways ====

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The effects of mitigation on water demand depends on the mitigation technologies deployed ( ''high confidence'' ) ( [[#Chaturvedi--2013a|Chaturvedi et al. 2013a]] ,b; [[#Hanasaki--2013|Hanasaki et al. 2013]] ; [[#Kyle--2013|Kyle et al. 2013]] ; [[#Hejazi--2014|Hejazi et al. 2014]] ; [[#Bonsch--2016|Bonsch et al. 2016]] ; [[#Jakob--2016|Jakob and Steckel 2016]] ; [[#Mouratiadou--2016|Mouratiadou et al. 2016]] ; [[#Fujimori--2017|Fujimori et al. 2017]] ; [[#Maïzi--2017|Maïzi et al. 2017]] ; [[#Bijl--2018|Bijl et al. 2018]] ; [[#Cui--2018|Cui et al. 2018]] ; [[#Graham--2018|Graham et al. 2018]] ; [[#Parkinson--2019|Parkinson et al. 2019]] ). Some mitigation options could increase water consumption (volume removed and not returned) while decreasing withdrawals (total volume of water removed, some of which may be returned) ( [[#Kyle--2013|Kyle et al. 2013]] ; [[#Fricko--2016|Fricko et al. 2016]] ; [[#Mouratiadou--2016|Mouratiadou et al. 2016]] ; [[#Parkinson--2019|Parkinson et al. 2019]] ). Bioenergy and BECCS can increase water withdrawals and water consumption ( ''high confidence'' ) ( [[#Chaturvedi--2013a|Chaturvedi et al. 2013a]] ; [[#Kyle--2013|Kyle et al. 2013]] ; [[#Hejazi--2014|Hejazi et al. 2014]] ; [[#Bonsch--2016|Bonsch et al. 2016]] ; [[#Jakob--2016|Jakob and Steckel 2016]] ; [[#Mouratiadou--2016|Mouratiadou et al. 2016]] ; [[#Fujimori--2017|Fujimori et al. 2017]] ; [[#Maïzi--2017|Maïzi et al. 2017]] ; [[#Séférian--2018|Séférian et al. 2018]] ; [[#Yamagata--2018|Yamagata et al. 2018]] ; [[#Parkinson--2019|Parkinson et al. 2019]] ) (AR6 WGII Chapter 4). DACCS ( [[#Fuhrman--2020|Fuhrman et al. 2020]] ) and CCS ( [[#Kyle--2013|Kyle et al. 2013]] ; [[#Fujimori--2017|Fujimori et al. 2017]] ) could increase water demand; however, the implications of CCS depend on the cooling technology and when capture occurs ( [[#Magneschi--2017|Magneschi et al. 2017]] ; [[#Maïzi--2017|Maïzi et al. 2017]] ; [[#Giannaris--2020|Giannaris et al. 2020]] ). Demand-side mitigation (e.g., dietary change, reduced food waste, reduced energy demand) can reduce water demand ( [[#Bajželj--2014|Bajželj et al. 2014]] ; Aleksandrowicz et al. 2016; [[#Green--2018|Green et al. 2018]] ; [[#Springmann--2018|Springmann et al. 2018]] ). Introducing specific measures (e.g., environmental flow requirements, improved efficiency, priority rules) can reduce water withdrawals ( [[#Bertram--2018|Bertram et al. 2018]] ; [[#Bijl--2018|Bijl et al. 2018]] ; [[#Parkinson--2019|Parkinson et al. 2019]] ).

The effect of mitigation on water quality depends on the mitigation option, its implementation, and the aspect of quality considered ( ''high confidence'' ) ( [[#Ng--2010|Ng et al. 2010]] ; [[#Flörke--2019|Flörke et al. 2019]] ; [[#Sinha--2019|Sinha et al. 2019]] ; [[#Smith--2019|Smith et al. 2019]] ; [[#Fuhrman--2020|Fuhrman et al. 2020]] ; [[#Karlsson--2020|Karlsson et al. 2020]] ; [[#McElwee--2020|McElwee et al. 2020]] ).

<div id="3.7.4" class="h2-container"></div>

<span id="energy"></span>
=== 3.7.4 Energy ===

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Energy is relevant to SDG 7 (affordable and clean energy). Access to sufficient levels of reliable, affordable and renewable energy is essential for sustainable development. Currently, over 1 billion people still lack access to electricity ( [[#Ribas--2019|Ribas et al. 2019]] ).

<div id="3.7.4.1" class="h3-container"></div>

<span id="benefits-of-avoided-climate-impacts-along-mitigation-pathways-2"></span>
==== 3.7.4.1 Benefits of Avoided Climate Impacts Along Mitigation Pathways ====

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Climate change alters the production of energy through changes in temperature (hydropower, fossil fuel, nuclear, solar, bioenergy, transmission and pipelines), precipitation (hydropower, fossil fuel, nuclear and bioenergy), windiness (wind and wave), and cloudiness (solar) ( ''high confidence'' ). Increases in temperature reduce efficiencies of thermal power plants (e.g., fossil fuel and nuclear plants) with air-cooled condensers by 0.4–0.7% per °C increase in ambient temperature ( [[#Cronin--2018a|Cronin et al. 2018a]] ; [[#Simioni--2019|Simioni and Schaeffer 2019]] ; Yalew, S.G. et al. 2020). Potentials and costs for renewable energy technologies are also affected by climate change, though with considerable regional variation and uncertainty ( [[#Gernaat--2021|Gernaat et al. 2021]] ). Biofuel yields could increase or decrease depending on the level of warming, changes in precipitation, and the effect of CO 2 fertilisation ( [[#Calvin--2013|Calvin et al. 2013]] ; [[#Kyle--2014|Kyle et al. 2014]] ; [[#Gernaat--2021|Gernaat et al. 2021]] ). Coastal energy facilities could potentially be impacted by sea level rise ( [[#Brown--2014|Brown et al. 2014]] ).

The energy sector uses large volumes of water ( [[#Fricko--2016|Fricko et al. 2016]] ), making it highly vulnerable to climate change ( [[#Tan--2016|Tan and Zhi 2016]] ) ( ''high confidence'' ) ''.'' Thermoelectric and hydropower sources are the most vulnerable to water stress ( [[#van%20Vliet--2016|van Vliet et al. 2016]] ). Restricted water supply to these power sources can affect grid security and affordable energy access ( [[#Koch--2014|Koch et al. 2014]] ; [[#Ranzani--2018|Ranzani et al. 2018]] ; [[#Zhang--2018d|Zhang et al. 2018d]] ).The hydropower facilities from high mountain areas of Central Europe, Iceland, Western USA/Canada, and Latin America ( [[#Hock--2019|Hock et al. 2019]] ), as well as Africa and China ( [[#Bartos--2015|Bartos and Chester 2015]] ; [[#Gaupp--2015|Gaupp et al. 2015]] ; [[#Tarroja--2016|Tarroja et al. 2016]] ; [[#Conway--2017|Conway et al. 2017]] ; [[#Byers--2018|Byers et al. 2018]] ; [[#Eyer--2018|Eyer and Wichman 2018]] ; [[#Ranzani--2018|Ranzani et al. 2018]] ; [[#Savelsberg--2018|Savelsberg et al. 2018]] ; [[#Zhang--2018d|Zhang et al. 2018d]] ; [[#Zhou--2018|Zhou et al. 2018]] ; [[#Wang--2019|Wang et al. 2019]] ) have experienced changes in seasonality and availability.

<div id="3.7.4.2" class="h3-container"></div>

<span id="implications-of-mitigation-efforts-along-pathways-2"></span>
==== 3.7.4.2 Implications of Mitigation Efforts Along Pathways ====

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Extending energy access to all in line with SDG7 is compatible with strong mitigation consistent with the Paris Agreement ( ''high confidence'' ). The Low Energy Demand (LED) scenario projects that these twin goals can be achieved by relying heavily on energy efficiency and rapid social transformations ( [[#Grubler--2018|Grubler et al. 2018]] ). The IEA’s Sustainable Development Scenario ( [[#IEA--2020a|IEA 2020a]] ) achieves development outcomes but with higher average energy use, and bottom-up modelling suggests that decent living standards could be provided to all in 2040–2050 with roughly 150 EJ, or 40% of current final energy use ( [[#Millward-Hopkins--2020|Millward-Hopkins et al. 2020]] ; [[#Kikstra--2021b|Kikstra et al. 2021b]] ). The trade-offs between climate mitigation and increasing energy consumption of the world’s poorest are negligible ( [[#Rao--2018|Rao and Min 2018]] ; [[#Scherer--2018|Scherer et al. 2018]] ).

The additional energy demand to meet the basic cooling requirement in the Global South is estimated to be much larger than the electricity needed to provide basic residential energy services universally via clean and affordable energy, as defined by SDG 7 ( [[#IEA--2019|IEA 2019]] ; [[#Mastrucci--2019|Mastrucci et al. 2019]] ) ( ''high confidence'' ) ''.'' If conventional air-conditioning systems are widely deployed to provide cooling, energy use could rise significantly ( [[#van%20Ruijven--2019|van Ruijven et al. 2019]] ; [[#Bezerra--2021|Bezerra et al. 2021]] ; [[#Falchetta--2021|Falchetta and Mistry 2021]] ), thus creating a positive feedback further increasing cooling demand. However, the overall emissions are barely altered by the changing energy demand composition with reductions in heating demand occurring simultaneously ( [[#Isaac--2009|Isaac and van Vuuren 2009]] ; [[#Labriet--2015|Labriet et al. 2015]] ; [[#McFarland--2015|McFarland et al. 2015]] ; [[#Clarke--2018|Clarke et al. 2018]] ). Some mitigation scenarios show price increases of clean cooking fuels, slowing the transition to clean cooking fuels (SDG 7.1) and leaving a billion people in 2050 still reliant on solid fuels in South Asia ( [[#Cameron--2016|Cameron et al. 2016]] ).

In contrast, future energy infrastructure could improve reliability, thus lowering dependence on high-carbon, high-air pollution back-up diesel generators ( [[#Farquharson--2018|Farquharson et al. 2018]] ) that are often used to cope with unreliable power in developing countries ( [[#Maruyama%20Rentschler--2019|Maruyama Rentschler et al. 2019]] ). There can be significant reliability issues where mini-grids are used to electrify rural areas ( [[#Numminen--2019|Numminen and Lund 2019]] ). A stable, sustainable energy transition policy that considers national sustainable development in the short and long term is critical in driving a transition to an energy future that addresses the trilemma of energy security, equity, and sustainability ( [[#La%20Viña--2018|La Viña et al. 2018]] ).

<div id="3.7.5" class="h2-container"></div>

<span id="health"></span>
=== 3.7.5 Health ===

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SDG 3 (good health and well-being) aims to ensure healthy lives and promote well-being for all at all ages. Climate change is increasingly causing injuries, illnesses, malnutrition, threats to mental health and well-being, and deaths (AR6 WGII Chapter 7). Mitigation policies and technologies to reduce GHG emissions are often beneficial for human health on a shorter time scale than benefits in terms of slowing climate change ( [[#Limaye--2020|Limaye et al. 2020]] ). The financial value of health benefits from improved air quality alone is projected to exceed the costs of meeting the goals of the Paris Agreement ( [[#Markandya--2018|Markandya et al. 2018]] ).

<div id="3.7.5.1" class="h3-container"></div>

<span id="benefits-of-avoided-climate-impacts-along-mitigation-pathways-3"></span>
==== 3.7.5.1 Benefits of Avoided Climate Impacts Along Mitigation Pathways ====

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The human health chapter of the WGII contribution to the AR6 concluded that climate change is increasingly affecting a growing number of health outcomes, with negative net impacts at the global scale and positive impacts only in a few limited situations. There are few estimates of economic costs of increases in climate-sensitive health outcomes. In the USA in 2012, the financial burden in terms of deaths, hospitalisations, and emergency department visits for ten climate-sensitive events across 11 states were estimated to be 10 (2.7–24.6) billion USD2018 ( [[#Limaye--2019|Limaye et al. 2019]] ).

<div id="3.7.5.2" class="h3-container"></div>

<span id="implications-of-mitigation-efforts-along-pathways-3"></span>
==== 3.7.5.2 Implications of Mitigation Efforts Along Pathways ====

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Transitioning toward equitable, low-carbon societies has multiple co-benefits for health and well-being (AR6 WGII Chapter 7). Health benefits can be gained from improvements in air quality through transitioning to renewable energy and active transport (e.g., walking and cycling); shifting to affordable low-meat, plant-rich diets; and green buildings and nature-based solutions, such as green-and-blue urban infrastructure, as shown in Figure 3.40 ( [[#Iacobucci--2016|Iacobucci 2016]] ).

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[[File:c13ea31566f7d629d55da1c5b788aa24 IPCC_AR6_WGIII_Figure_3_40.png]]

'''Figure 3.40 | Diagram showing the co-benefits between health and mitigation.''' Source: with permission from [[#Iacobucci--2016|Iacobucci 2016]] .

The avoided health impacts associated with climate change mitigation can substantially offset mitigation costs at the societal level ( [[#Ščasný--2015|Ščasný et al. 2015]] ; [[#Schucht--2015|Schucht et al. 2015]] ; [[#Chang--2017|Chang et al. 2017]] ; [[#Markandya--2018|Markandya et al. 2018]] ). Models of health co-benefits show that a 1.5°C pathway could result in 152 million ± 43 million fewer premature deaths worldwide between 2020 and 2100 in comparison to a business-as-usual scenario, particularly due to reductions in exposure to PM2.5 ( [[#Shindell--2018|Shindell et al. 2018]] ; [[#Rauner--2020a|Rauner et al. 2020a]] ; [[#Rafaj--2021|Rafaj et al. 2021]] ). Some of the most substantial health, well-being, and equity benefits associated with climate action derive from investing in basic infrastructure: sanitation, clean drinking water, clean energy, affordable healthy diets, clean public transport, and improved air quality from transformative solutions across economic sectors including agriculture, energy, transport and buildings ( [[#Chang--2017|Chang et al. 2017]] ).

The health co-benefits of the NDCs for 2040 were compared for two scenarios, one consistent with the goal of the Paris Agreement and the SDGs and the other also placing health as a central focus of the policies (i.e., health in all climate policies scenario) ( [[#Hamilton--2021|Hamilton et al. 2021]] ), for Brazil, China, Germany, India, Indonesia, Nigeria, South Africa, the UK, and the USA. Modelling of the energy, food and agriculture, and transport sectors, and associated risk factors related to mortality, suggested the sustainable pathways scenario could result in annual reductions of 1.18 million air pollution-related deaths, 5.86 million diet-related deaths, and 1.15 million deaths due to physical inactivity. Adopting the more ambitious health in all climate policies scenario could result in further reductions of 462,000 annual deaths attributable to air pollution, 572,000 annual deaths attributable to diet, and 943,000 annual deaths attributable to physical inactivity. These benefits were attributable to the mitigation of direct GHG emissions and the commensurate actions that reduce exposure to harmful pollutants, as well as improved diets and safe physical activity.

Cost-benefit analyses for climate mitigation in urban settings that do not account for health may underestimate the potential cost savings and benefits ( [[#Hess--2020|Hess et al. 2020]] ). The net health benefits of controlling air pollution as part of climate mitigation efforts could reach trillions of dollars annually, depending on the air quality policies adopted globally ( [[#Markandya--2018|Markandya et al. 2018]] ; [[#Scovronick--2019b|Scovronick et al. 2019b]] ). Air pollution reductions resulting from meeting the Paris Agreement targets were estimated to provide health co-benefits-to-mitigation ratios of between 1.4 and 2.5 ( [[#Markandya--2018|Markandya et al. 2018]] ). In Asia, the benefit of air pollution reduction through mitigation measures was estimated to reduce premature mortality by 0.79 million, with an associated health benefit of USD2.8 trillion versus mitigation costs of USD840 billion, equating to 6% and 2% of GDP, respectively ( [[#Xie--2018|Xie et al. 2018]] ). Similarly, stabilising radiative forcing to 3.4 W m –2 in South Korea could cost USD1.3–8.5 billion in 2050 and could lead to a USD23.5 billion cost reduction from the combined benefits of avoided premature mortality, health expenditures, and lost work hours ( [[#Kim--2020|Kim et al. 2020]] ). The health co-benefits related to physical exercise and reduced air pollution largely offset the costs of implementing low-CO 2 -emitting urban mobility strategies in three Austrian cities ( [[#Wolkinger--2018|Wolkinger et al. 2018]] ).

Just inthe USA, over the next 50 years, a 2°C pathway could prevent roughly 4.5 million premature deaths, about 3.5 million hospitalisations and emergency room visits, and approximately 300 million lost workdays ( [[#Shindell--2020|Shindell 2020]] ). The estimated yearly benefits of USD700 billion were more than the estimated cost of the energy transition.

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<span id="biodiversity-land-and-water"></span>
=== 3.7.6 Biodiversity (Land and Water) ===

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Biodiversity covers life below water (SDG 14) and life on land (SDG 15). Ecosystem services are relevant to the goals of zero hunger (SDG 2), good health and well-being (SDG 3), clean water and sanitation (SDG 6) and responsible consumption and production (SDG 12), as well as being essential to human existence (IPBES 2019).

<div id="3.7.6.1" class="h3-container"></div>

<span id="benefits-of-avoided-climate-impacts-along-mitigation-pathways-4"></span>
==== 3.7.6.1 Benefits of Avoided Climate Impacts Along Mitigation Pathways ====

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<div id="Terrestrial and freshwater aquatic ecosystems" class="h4-container"></div>

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===== Terrestrial and freshwater aquatic ecosystems =====

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Climate change is a major driver of species extinction and terrestrial and freshwater ecosystems destruction ( ''high confidence'' ) (AR6 WGII Chapter 2). Analysis shows that approximately half of all species with long-term records have shifted their ranges in elevation and about two thirds have advanced their timing of spring events ( [[#Parmesan--2015|Parmesan and Hanley 2015]] ). Under 3.2°C warming, 49% of insects, 44% of plants and 26% of vertebrates are projected to be at risk of extinction. At 2°C, this falls to 18% of insects, 16% of plants and 8% of vertebrates and at 1.5°C, to 6% of insects, 8% of plants and 4% of vertebrates ( [[#Warren--2018|Warren et al. 2018]] ). Incidents of migration of invasive species, including pests and diseases, are also attributable to climate change, with negative impacts on food security and vector-borne diseases. Moreover, if climate change reduces crop yields, cropland may expand – a primary driver of biodiversity loss – in order to meet food demand ( [[#Molotoks--2020|Molotoks et al. 2020]] ). Land restoration and halting land degradation under all mitigation scenarios has the potential for synergy between mitigation and adaptation.

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===== Marine and coastal ecosystems =====

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Marine ecosystems are being affected by climate change and growing non-climate pressures including temperature change, acidification, land-sourced pollution, sedimentation, resource extraction and habitat destruction ( ''high confidence'' ) ( [[#Bindoff--2019|Bindoff et al. 2019]] ; [[#IPCC--2019b|IPCC 2019b]] ). The impacts of climate drivers and their combinations vary across taxa (AR6 WGII Chapter 3). The danger or warming and acidification to coral reefs, rocky shores and kelp forests is well established ( ''high confidence'' ) (AR6 WGII Chapter 3). Migration towards optimal thermal and chemical conditions ( [[#Burrows--2019|Burrows et al. 2019]] ) contributes to large-scale redistribution of fish and invertebrate populations, and major impacts on global marine biomass production and maximum sustainable yield ( [[#Bindoff--2019|Bindoff et al. 2019]] ).

<div id="3.7.6.2" class="h3-container"></div>

<span id="implications-of-mitigation-efforts-along-pathways-4"></span>
==== 3.7.6.2 Implications of Mitigation Efforts Along Pathways ====

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Mitigation measures have the potential to reduce the progress of negative impacts on ecosystems, although it is ''unlikely'' that all impacts can be mitigated ( ''high confidence'' ) ( [[#Ohashi--2019|Ohashi et al. 2019]] ). The specifics of mitigation achievement are crucial, since large-scale deployment of some climate mitigation and land-based CDR measures could have deleterious impacts on biodiversity ( [[#Santangeli--2016|Santangeli et al. 2016]] ; [[#Hof--2018|Hof et al. 2018]] ).

Climate change mitigation actions to reduce or slow negative impacts on ecosystems are ''likely'' to support the achievement of SDGs 2, 3, 6, 12, 14 and 15. Some studies show that stringent and constant GHG mitigation practices bring a net benefit to global biodiversity even if land-based mitigation measures are also adopted ( [[#Ohashi--2019|Ohashi et al. 2019]] ), as opposed to delayed action which would require much more widespread use of BECCS. Scenarios based on demand reductions of energy and land-based production are expected to avoid many such consequences, due to their minimised reliance on BECCS ( [[#Conijn--2018|Conijn et al. 2018]] ; [[#Grubler--2018|Grubler et al. 2018]] ; [[#Bowles--2019|Bowles et al. 2019]] ; [[#Soergel--2021a|Soergel et al. 2021a]] ). Stringent mitigation that includes reductions in demand for animal-based foods and food waste could also relieve pressures on land use and biodiversity ( ''high confidence'' ), both directly by reducing agricultural land requirements ( [[#Leclère--2020|Leclère et al. 2020]] ) and indirectly by reducing the need for land-based CDR ( [[#van%20Vuuren--2018|van Vuuren et al. 2018]] ).

As environmental conservation and sustainable use of the Earth’s terrestrial species and ecosystems are strongly related, recent studies have evaluated interconnections among key aspects of land and show a pathway to the global sustainable future of land ( [[#Popp--2014|Popp et al. 2014]] ; [[#Erb--2016|Erb et al. 2016]] ; [[#Obersteiner--2016|Obersteiner et al. 2016]] ; [[#Humpenöder--2018|Humpenöder et al. 2018]] ). Most studies agree that many biophysical options exist to achieve global climate mitigation and sustainable land use in future. Conserving local biodiversity requires careful policy design in conjunction with land-use regulations and societal transformation in order to minimise the conversion of natural habitats.

<div id="3.7.7" class="h2-container"></div>

<span id="infrastructure"></span>
=== 3.7.7 Infrastructure ===

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This subsection focuses upon SDG 9 (industry, innovation and infrastructure) and SDG 11 (sustainable cities and communities).

<div id="3.7.7.1" class="h3-container"></div>

<span id="benefits-of-avoided-climate-impacts-along-mitigation-pathways-5"></span>
==== 3.7.7.1 Benefits of Avoided Climate Impacts Along Mitigation Pathways ====

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By 2100, urban population will be almost double and more urban areas will be built ( [[#Jiang--2017|Jiang and O’Neill 2017]] ), although COVID-19 may modify these trends ( [[#Kii--2021|Kii 2021]] ). Urbanisation will amplify projected air temperature changes in cities, including amplifying heatwaves (AR6 WGI Chapter 10, Box 10.3). Benefits of climate mitigation in urban areas include reducing heat, air pollution and flooding. Industrial infrastructure and production-consumption supply networks also benefit from avoided impacts.

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<span id="implications-of-mitigation-efforts-along-pathways-5"></span>
==== 3.7.7.2 Implications of Mitigation Efforts Along Pathways ====

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Many co-benefits to urban mitigation actions (Chapter 8, [[IPCC:Wg3:Chapter:Chapter-8#8.2.1|Section 8.2.1]] ) improve the liveability of cities and contribute to achieving SDG 11. In particular, compact urban form, efficient technologies and infrastructure can play a valuable role in mitigation by reducing energy demand ( [[#Creutzig--2016|Creutzig et al. 2016]] ; [[#Güneralp--2017|Güneralp et al. 2017]] ), thus averting carbon lock-in, while reducing land sprawl and hence increasing carbon storage and biodiversity ( [[#D’Amour--2017|D’Amour et al. 2017]] ). Benefits of mitigation include air quality improvements from decreased traffic and congestion when private vehicles are displaced by other modes; health benefits from increases in active travel; and lowered urban heat island effects from green-blue infrastructures ( [[IPCC:Wg3:Chapter:Chapter-8#8.2.1|Section 8.2.1]] ).

However, increasing urban density or enlarging urban green spaces can increase property prices and reduce affordability ( [[IPCC:Wg3:Chapter:Chapter-8#8.2.1|Section 8.2.1]] ). Raising living conditions for slum dwellers and people living in informal settlements will require significant materials and energy; however, regeneration can be conducted in ways that avoid carbon-intense infrastructure lock-in (Chapters 8 and 9). Cities affect other regions through supply chains ( [[#Marinova--2020|Marinova et al. 2020]] ).

Sustainable production, consumption and management of natural resources are consistent with, and necessary for, mitigation (Chapters 5 and 11). Demand-side measures can lower requirements for upstream material and energy use (Chapter 5). In terms of industrial production, transformational changes across sectors will be necessary for mitigation (Sections 11.3 and 11.4).

Addressing multiple SDG arenas requires new systemic thinking in the areas of governance and policy, such as those proposed by [[#Sachs--2019|Sachs et al. (2019)]] .

<div id="3.8" class="h1-container"></div>

<span id="sociotechnoeconomic-transitions"></span>