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

=== 8.4.7 Cross-sectoral Integration ===

<div id="h2-22-siblings" class="h2-siblings"></div>

There are two broad categories of urban mitigation strategies. One is from the perspective of key sectors, including clean energy, sustainable transport, and construction ( [[#Rocha--2017|Rocha et al. 2017]] ; [[#Álvarez%20Fernández--2018|Álvarez Fernández 2018]] ; [[#Magueta--2018|Magueta et al. 2018]] ; [[#Seo--2018|Seo et al. 2018]] ; [[#Waheed--2018|Waheed et al. 2018]] ); the coupling of these sectors can be enabled through electrification ( [[#8.4.3.1|Section 8.4.3.1]] ). The other looks at the needs for emissions through a more systematic or fundamental understanding of urban design, urban form, and urban spatial planning ( [[#Wang--2017|Wang et al. 2017]] ; [[#Privitera--2018|Privitera et al. 2018]] ), and proposes synergistic scenarios for their integration for carbon neutrality ( [[#Ravetz--2020|Ravetz et al. 2020]] ).

Single-sector analysis in low-carbon urban planning examines solutions in supply, demand, operations, and assets management either from technological efficiency or from a system approach. For example, the deployment of renewable energy technologies for urban mitigation can be evaluated in detail and the transition to zero-carbon energy in energy systems and EVs in the transport sector can bring about a broad picture for harvesting substantial low-carbon potentials through urban planning ( ''high agreement'' , ''robust evidence'' ) ( [[#Álvarez%20Fernández--2018|Álvarez Fernández 2018]] ; [[#Tarigan--2018|Tarigan and Sagala 2018]] ).

The effects of urban carbon lock-in on land use, energy demand, and emissions vary depending on national circumstances ( [[#Wang--2017|Wang et al. 2017]] ; [[#Pan--2020|Pan 2020]] ). Systematic consideration of urban spatial planning and urban forms, such as polycentric urban regions and rational urban population density, is essential not only for liveability but also for achieving net-zero GHG emissions as it aims to shorten commuting distances and is able to make use of NBS for energy and resilience ( ''high agreement'' , ''medium evidence'' ). However, crucial knowledge gaps remain in this field. There is a shortage of consistent and comparable GHG emissions data at the city level and a lack of in-depth understanding of how urban renewal and design can contribute to carbon neutrality ( [[#Mi--2019|Mi et al. 2019]] ).

An assessment of opportunities suggests that strategies for material efficiency that cross-cut sectors will have greater impact than those that focus one-dimensionally on a single sector ( [[#UNEP%20IRP--2020|UNEP IRP 2020]] ). In the urban context, this implies using less material by the design of physical infrastructure based on light-weighting and down-sizing, material substitution, prolonged use, as well as enhanced recycling, recovery, remanufacturing, and reuse of materials and related components. For example, light-weight design in residential buildings and passenger vehicles can enable about 20% reductions in lifecycle material-related GHG emissions ( [[#UNEP%20IRP--2020|UNEP IRP 2020]] ).

The context of urban areas as the nexus of both sectors (i.e., energy, and urban form and planning) underlines the role of urban planning and policies in contributing to reductions in material-related GHG emissions while enabling housing and mobility services for the benefit of inhabitants. In addition, combining resource efficiency measures with strategic densification can increase the GHG reduction potential and lower resource impacts. While resource efficiency measures are estimated to reduce GHG emissions, land use, water consumption, and metal use impacts from a lifecycle assessment perspective by 24–47% over a baseline, combining resource efficiency with strategic densification can increase this range to about 36–54% over the baseline for a sample of 84 urban settlements worldwide ( [[#Swilling--2018|Swilling et al. 2018]] ).

Evidence from a systematic scoping of urban solutions further indicates that the GHG abatement potential of integrating measures across urban sectors is greater than the net sum of individual interventions due to the potential of realising synergies when realised in tandem, such as urban energy infrastructure and renewable energy ( [[#Sethi--2020|Sethi et al. 2020]] ). Similarly, system-wide interventions, such as sustainable urban form, are important for increasing the GHG abatement potential of interventions based on individual sectoral projects ( [[#Sethi--2020|Sethi et al. 2020]] ). Overall, the pursuit of inter-linkages among urban interventions is important for accelerating GHG reductions in urban areas ( [[#Sethi--2020|Sethi et al. 2020]] ); this is also important for reducing reliance on carbon capture and storage technologies (CCS) at the global scale (Figures 8.15 and 8.21).

Currently, cross-sectoral integration is one of the main thematic areas of climate policy strategies among the actions that are adopted by signatories to an urban climate and energy network ( [[#Hsu--2020c|Hsu et al. 2020c]] ). Although not as prevalent as those for efficiency, municipal administration, and urban planning measures ( [[#Hsu--2020c|Hsu et al. 2020c]] ), strategies that are cross-cutting in nature across sectors can provide important emission-saving opportunities for accelerating the pace of climate mitigation in urban areas. Cross-sectoral integration also involves mobilising urban actors to increase innovation in energy services and markets beyond individual energy efficiency actions ( [[#Hsu--2020c|Hsu et al. 2020c]] ). Indeed, single-sector versus cross-sector strategies for 637 cities from a developing country can enable an additional 15–36% contribution to the national climate mitigation reduction potential ( [[#Ramaswami--2017a|Ramaswami et al. 2017a]] ). The strategies at the urban level involved those for energy cascading and exchange of materials that connected waste, heat, and electricity strategies ( [[#8.5|Section 8.5]] and Box 8.4).

The feasibility of upscaling multiple response options depends on the urban context as well as the stage of urban development, with certain stages providing additional opportunities over others ( [[#Dienst--2015|Dienst et al. 2015]] ; [[#Maier--2016|Maier 2016]] ; [[#Affolderbach--2017|Affolderbach and Schulz 2017]] ; [[#Roldán-Fontana--2017|Roldán-Fontana et al. 2017]] ; [[#Zhao--2017a|Zhao et al. 2017a]] ; [[#Beygo--2017|Beygo and Yüzer 2017]] ; [[#Lwasa--2017|Lwasa 2017]] ; [[#Pacheco-Torres--2017|Pacheco-Torres et al. 2017]] ; [[#Alhamwi--2018|Alhamwi et al. 2018]] ; [[#Kang--2018|Kang and Cho 2018]] ; [[#Lin--2018|Lin et al. 2018]] ; [[#Collaço--2019|Collaço et al. 2019]] ) (Figures 8.19 and 8.21, and Section 8.SM.2).

<div id="8.5" class="h1-container"></div>

<span id="governance-institutio-ns-and-finance"></span>