Editing IPCC:AR6/WGII/Cross-Chapter-Paper-2 (section)

=== CCP2.3.1 Introduction ===

<div id="h2-3-siblings" class="h2-siblings"></div>

This section extends SROCC [[IPCC:Wg2:Chapter:Chapter-4|Chapter 4]] ( [[#Oppenheimer--2019|Oppenheimer et al., 2019]] ), which focused on SLR, and draws from Chapters 6 and 9–15 to cover all C&amp;S archetypes. Adaptation interventions span psychosocial (e.g., awareness raising), economic (e.g., insurance), physical (e.g., retreat), technical (e.g., sea walls) and natural dimensions (e.g., wetland restoration; [[#Nicholls--2015|Nicholls et al., 2015]] ). Adaptation strategies for coastal C&amp;S are typically classified in terms of protect, accommodate, advance and retreat, which are used below.

Some coastal cities have adapted to meters of SLR in the past, indicating that adaptation is feasible ( [[#Esteban--2020a|Esteban et al., 2020a]] ), but future adaptation options are influenced by variations in projected socioeconomic conditions and rates of SLR (Cross-Chapter Box SLR in Chapter 3). To date, interventions are typically implemented reactively in response to extreme events ( ''high confidence'' ), but leading adaptors are increasingly proactive ( ''medium confidence'' ; [[#Araos--2016|Araos et al., 2016]] ; [[#Dulal--2019|Dulal, 2019]] ; [[#Dedekorkut-Howes--2020|Dedekorkut-Howes et al., 2020]] ) and those that move from previously rigid to more adaptive and flexible solutions, using an adaptation-pathways approach that keeps options open in the face of uncertainty, have improved climate risk management ( ''high confidence'' ; Sections 9.9.4; 10.5; 11.7; 12.5.5; 13.2; 14.7; 15.5; Cross-Chapter Box DEEP in Chapter 17; [[#Walker--2013|Walker et al., 2013]] ; [[#Marchau--2019|Marchau et al., 2019]] ).

The effectiveness of different strategies and interventions is mediated by physical coastal features for hard adaptation measures and by the scope and depth of soft adaptation measures, for example by the coverage and extent of social safety nets for the urban poor ( [[IPCC:Wg2:Chapter:Chapter-6#6.3|Section 6.3]] ). Their feasibility is also shaped by socioeconomic, cultural, political and institutional factors, for example social acceptance of measures (Section CCP2.2, SMCCP2.2.4). Together, response effectiveness and feasibility shape the solution space for mediating risks ( [[IPCC:Wg2:Chapter:Chapter-1#1.3.1.2|Section 1.3.1.2]] ; Figure CCP2.3; [[#Simpson--2021|Simpson et al., 2021]] ), which is achieved chiefly through governance interventions, for example laws and regulations ( [[#Haasnoot--2020|Haasnoot et al., 2020]] ). Access to financial resources expands the solution space, most notably for some resource-rich coastal archetypes (Section CCP2.4.2; Table SMCCP2.1; Sections 3.6; 14.7), but rapid population growth and unfolding climate-driven impacts can increase risks ( [[#Haasnoot--2021a|Haasnoot et al., 2021a]] ), especially for small island and poorer C&amp;S ( ''high confidence'' ; [[IPCC:Wg2:Chapter:Chapter-15#15.3|Section 15.3]] ; [[#Magnan--2020|Magnan and Duvat, 2020]] ).

<div id="CCP2.3.2" class="h2-container"></div>

<span id="ccp2.3.2-protection-of-coastal-cities-and-settlements"></span>