Editing IPCC:AR6/WGIII/Chapter-8 (section)

=== 8.2.1 Sustainable Development ===

<div id="h2-7-siblings" class="h2-siblings"></div>

Sustainable development is a broad concept, encompassing socio-economic and environmental dimensions, envisaging long-term permanence and improvement. While long-term effects are more related to resilience – and hence carry co-benefits and synergies with the mitigation of GHG emissions – some short-term milestones were defined by the post-2015 UN Sustainable Development Agenda SDGs, including a specific goal on climate change (SDG 13) and one on making cities inclusive, safe, resilient and sustainable (SDG 11) ( [[#United%20Nations--2015|United Nations 2015]] ). The SDGs and related indicators can be an opportunity to improve cities by using science-based decision-making and engaging a diverse set of stakeholders ( [[#Simon--2016|Simon et al. 2016]] ; [[#Klopp--2017|Klopp and Petretta 2017]] ; [[#Kutty--2020|Kutty et al. 2020]] ).

There are multiple ways that development pathways can be shifted towards sustainability ( [[IPCC:Wg3:Chapter:Chapter-4#4.3.3|Section 4.3.3]] , Cross-Chapter Box 5 in Chapter 4, [[IPCC:Wg3:Chapter:Chapter-17|Chapter 17]] and Figure 17.1). Urban areas can work to redirect development pathways towards sustainability while increasing co-benefits for urban inhabitants. Figure 8.4 indicates that mitigation options for urban systems can provide synergistic linkages across a wide range of SDGs, and some cases where linkages can produce both synergies and trade-offs. While linkages are based on context and the scale of implementation, synergies can be most significant when urban areas pursue integrated approaches where one mitigation option supports the other (Sections 8.4 and 8.6).

Figure 8.4 summarises an evaluation of the synergies and/or trade-offs with the SDGs for the mitigation options for urban systems based on Supplementary Material 8.SM.1. The evaluations depend on the specific urban context, with synergies and/or trade-offs being more significant in certain contexts than others. Urban mitigation with a view of the SDGs can support shifting pathways of urbanisation towards greater sustainability. The feasibility of urban mitigation options is also malleable and can increase with more ‘enabling conditions’ (see Glossary), provided, perhaps, through institutional (i.e., financial or governmental) support ( [[#8.5|Section 8.5]] ). Strengthened institutional capacity that supports the coordination of mitigation options can increase linkages with the SDGs and their synergies. For example, urban land use and spatial planning for walkable and co-located densities, together with electrification of the urban energy system, can hold more benefits for the SDGs than any one of the mitigation options alone (Sections 8.4.2.3, 8.4.3.1 and 8.6).

<div id="_idContainer006e" class="Basic-Text-Frame"></div>

[[File:2d002c2ec51d054362f5bdb686d7f3ba IPCC_AR6_WGIII_Figure_8_4.png]]

'''Figure 8.4: Co-benefits of urban mitigation actions.''' The first column lists urban mitigation options. The second column indicates synergies with the SDGs. The third column indicates both synergies and/or trade-offs. The dots represent confidence levels with the number of dots representing levels from low to high. In the last column, confidence levels for synergies and/or trade-offs are provided separately. A plus sign (+) represents synergy and a minus sign (–) represents a trade-off. Supplementary Material 8.SM.1 provides 64 references and extends the SDG mappings that are provided in [[#Thacker--2019|Thacker et al. (2019)]] and [[#Fuso%20Nerini--2018|Fuso Nerini et al. (2018)]] . Please see Table 17.SM.1 for details and Annex II for the methodology of the SDG assessment.

Evidence on the co-benefits of urban mitigation measures for human health has increased significantly since AR5, especially through the use of health impact assessments, where energy savings and cleaner energy supply structures based on measures for urban planning, heating, and transport have reduced CO 2 , nitrogen oxides (NO x ), and coarse particulate matter (PM 10 ) emissions ( [[#Diallo--2016|Diallo et al. 2016]] ). Some measures, especially those related to land-use planning and transportation, have also increased opportunities for physical activity for improved health ( [[#Diallo--2016|Diallo et al. 2016]] ). In developing countries, the co-benefits approach has been effective in justifying climate change mitigation actions at the local level ( [[#Puppim%20de%20Oliveira--2016|Puppim de Oliveira and Doll 2016]] ). Mixed-use compact development with sufficient land-use diversity can have a positive influence on urban productivity ( [[#8.4.2|Section 8.4.2]] ). Conversely, urban spatial structures that increase walking distances and produce car dependency have negative impacts on urban productivity considering congestion as well as energy costs ( [[#Salat--2017|Salat et al. 2017]] ).

There is increasing evidence that climate mitigation measures can lower health risks that are related to energy poverty, especially among vulnerable groups such as the elderly and in informal settlements ( [[#Monforti-Ferrario--2018|Monforti-Ferrario et al. 2018]] ). Measures such as renewable energy-based electrification of the energy system not only reduce outdoor air pollution, but also enhance indoor air quality by promoting smoke-free heating and cooking in buildings ( [[#Kjellstrom--2013|Kjellstrom and McMichael 2013]] ). The environmental and ecological benefits of electrification of the urban energy system include improved air quality based on a shift to non-polluting energy sources ( [[#Jacobson--2018|Jacobson et al. 2018]] ; [[#Ajanovic--2019|Ajanovic and Haas 2019]] ; [[#Bagheri--2019|Bagheri et al. 2019]] ; [[#Gai--2020|Gai et al. 2020]] ). Across 74 metropolitan areas around the world, an estimated 408,270 lives per year are saved due to air quality improvements that stem from a move to 100% renewable energy ( [[#Jacobson--2020|Jacobson et al. 2020]] ). Other studies indicate that there is potential to reduce premature mortality by up to 7000 people in 53 towns and cities, to create 93,000 new jobs, and to lower global climate costs and personal energy costs, through renewable energy transformations ( [[#Jacobson--2018|Jacobson et al. 2018]] ).

Across 146 signatories of a city climate network, local energy-saving measures led to 6596 avoided premature deaths and 68,476 years of life saved due to improved air quality ( [[#Monforti-Ferrario--2018|Monforti-Ferrario et al. 2018]] ). Better air quality further reinforces the health co-benefits of climate mitigation measures based on walking and bicycling since evidence suggests that increased physical activity in urban outdoor settings with low levels of black carbon improves lung function ( [[#Laeremans--2018|Laeremans et al. 2018]] ). Physical activity can also be fostered through urban design measures and policies that promote the development of ample and well-connected parks and open spaces, and can lead to physical and mental health benefits ( [[#Kabisch--2016|Kabisch et al. 2016]] ) ( [[#8.4.4|Section 8.4.4]] and Figure 8.18).

Cities in India, Indonesia, Vietnam, and Thailand show that reducing emissions from major sources (e.g., transport, residential burning, biomass open burning, and industry) could bring substantial co-benefits of avoided deaths from reduced PM 2.5 (fine inhalable particulates) emissions and radiative forcing from black carbon ( [[#Pathak--2016|Pathak and Shukla 2016]] ; [[#Dhar--2017|Dhar et al. 2017]] ; [[#Permadi--2017|Permadi et al. 2017]] ; [[#Karlsson--2020|Karlsson et al. 2020]] ), reduced noise, and reduced traffic injuries ( [[#Kwan--2016|Kwan and Hashim 2016]] ). Compact city policies and interventions that support a modal shift away from private motor vehicles towards walking, cycling, and low-emission public transport delivers significant public health benefits ( [[#Creutzig--2016|Creutzig 2016]] ; [[#Ürge-Vorsatz--2018|Ürge-Vorsatz et al. 2018]] ). Trade-offs associated with compact development include the marginal health costs of transport air pollution (Lohrey and [[#Creutzig--2016|Creutzig 2016]] ) and stress from traffic noise ( [[#Gruebner--2017|Gruebner et al. 2017]] ) ( [[#8.4.2.3|Section 8.4.2.3]] ).

Urban green and blue infrastructure – a subset of nature-based solutions (NBS) – acts as both climate mitigation and adaptation measures by reducing heat stress ( [[#Kim--2018|Kim and Coseo 2018]] ; [[#Privitera--2018|Privitera and La Rosa 2018]] ; [[#Herath--2021|Herath et al. 2021]] ), improving air quality, reducing noise ( [[#Scholz--2018|Scholz et al. 2018]] ; [[#De%20la%20Sota--2019|De la Sota et al. 2019]] ), improving urban biodiversity ( [[#Hall--2017b|Hall et al. 2017b]] ), and enhancing well-being, including contributions to local development ( [[#Lwasa--2015|Lwasa et al. 2015]] ). Health benefits from urban forestry and green infrastructure include reduced cardiovascular morbidity, improved mental health ( [[#van%20den%20Bosch--2017|van den Bosch and Ode Sang 2017]] ; [[#Vujcic--2017|Vujcic et al. 2017]] ; [[#Al-Kindi--2020|Al-Kindi et al. 2020]] ; [[#Sharifi--2021|Sharifi et al. 2021]] ), raised birth weight ( [[#Dzhambov--2014|Dzhambov et al. 2014]] ), and increased life expectancy ( [[#Jonker--2014|Jonker et al. 2014]] ). Urban agriculture, including urban orchards, rooftop gardens, and vertical farming contribute to enhancing food security and fostering healthier diets ( [[#Cole--2018|Cole et al. 2018]] ; [[#Petit-Boix--2018|Petit-Boix and Apul 2018]] ; [[#De%20la%20Sota--2019|De la Sota et al. 2019]] ) ( [[#8.4.4|Section 8.4.4]] , Figure 8.18 and Box 8.2).

<div id="8.2.2" class="h2-container"></div>

<span id="economic-development-competitiveness-and-equity"></span>