Editing IPCC:AR6/WGII/Cross-Chapter-Paper-5 (section)

=== CCP5.4.1 Synthesis of Adaptation Responses to Reducing (Key) Risks ===

<div id="h2-10-siblings" class="h2-siblings"></div>

More than half of the studies having a focus on mountains (423 articles) extracted from the GAMI data set report that adaptation responses contribute to reducing climate risks ( [[#Berrang-Ford--2021|Berrang-Ford et al., 2021]] ; [[#McDowell--2021b|McDowell et al., 2021b]] ) (SMCCP5.3.2). However, the extent of adaptation in terms of time (i.e., speed), scale of change (i.e., scope) and depth of change (i.e., degree to which a change is substantial) is low in mountain regions, with the level of agreement across studies varying from one region to the other ( ''medium confidence'' ) (Figure CCP5.7, SMCCP5.3.2). In regions where risk levels remain moderate, a low adaptation extent might be sufficient to constrain risks (Figures CCP5.5 and 5.6, [[IPCC:Wg2:Chapter:Chapter-16#16.3.2.4|Section 16.3.2.4]] ).

<div id="_idContainer023" class="Figure"></div>

[[File:93f5e0a158c44994e5687ad1019be80f IPCC_AR6_WGII_Figure_CCP5_007.png]]

'''Figure CCP5.7 |''' '''Extent of planned and implemented adaptation actions observed in mountain regions shown in terms of three dimensions:''' '''i) speed (timeframe within which adaptations are implemented), ii) scope (scale of changes observed from adaptation action), and iii) its depth (i.''' e ., degree to which a change reflects something new) ( [[IPCC:Wg2:Chapter:Chapter-16#16.3.2.4|Section 16.3.2.4]] ). The data are obtained from the Global Adaptation Mapping Initiative (GAMI) reanalysis for mountains (SMCCP5.3.2) ( [[#Berrang-Ford--2021|Berrang-Ford et al., 2021]] ; [[#McDowell--2021b|McDowell et al., 2021b]] ).

Adaptation responses in mountains are mainly incremental changes from existing practices ( ''high confidence'' ) ( [[#McDowell--2019|McDowell et al., 2019]] , 2021b; [[#Rasul--2020|Rasul et al., 2020]] ), signalling that the potential of current and planned adaptation responses to reduce risks in the future will not be adequate to mitigate high to very high risks. For example, measures to contain floods or landslides (KR1) are designed with specific magnitudes and types in mind, often assuming stationarity of return periods ( [[#Montanari--2014|Montanari and Koutsoyiannis, 2014]] ; [[#Gariano--2016|Gariano and Guzzetti, 2016]] ). In the case of events showing decreasing return periods, risk mitigation standards need to be elevated to provide for more protection in the future ( [[#Felder--2018|Felder et al., 2018]] ; [[#François--2019|François et al., 2019]] ). The portfolio of adaptation options to mitigate risks from changing water resources (KR2) is large but challenging and includes integrated catchment management, implementation of multiple use of water strategies, improved water governance (including community-based and participatory water governance), overcoming power inequalities among users and sectors and balancing economic pressure and sustainable development ( ''high confidence'' ) ( [[#Bekchanov--2016|Bekchanov and Lamers, 2016]] ; [[#Yapiyev--2017|Yapiyev et al., 2017]] ; [[#Jalilov--2018|Jalilov et al., 2018]] ; [[#Drenkhan--2019|Drenkhan et al., 2019]] ; [[#Allen--2020|Allen et al., 2020]] ; [[#Aggarwal--2021|Aggarwal et al., 2021]] ; [[#Huang--2021|Huang et al., 2021]] ) (SMCCP5.3.2). There is ''limited evidence'' on the effectiveness of adaptation responses to reduce the severity of ecosystem change (KR3) (also see [[IPCC:Wg2:Chapter:Chapter-16#16.3.1|Section 16.3.1]] ). Prevention rather than control and eradication efforts can contribute to curbing biological invasions of alien species in the short turn, whereas colonisation by native trees following land use abandonment can be more effective in the long run ( [[#Carboni--2018|Carboni et al., 2018]] ). Reducing intensified grazing, agricultural expansion and conservation management in buffer zones of protected areas can limit the altitudinal range shift of endemic species ( [[#Kidane--2019|Kidane et al., 2019]] ).

EbA has been effective in mountain regions at reducing risks from floods (e.g., restoration of buffer zones and floodplains) and landslides (e.g., protective forests) ( [[#Muccione--2016|Muccione and Daley, 2016]] ; [[#Klein--2019b|Klein et al., 2019b]] ; [[#Lavorel--2019|Lavorel et al., 2019]] ). Ecosystem-based measures have been implemented for water management purposes to supply clean water and improve water quality ( [[IPCC:Wg2:Chapter:Chapter-4#4.6.6|Section 4.6.6]] ). Furthermore, they provide scope for conservation and improvement of habitats, e.g., forest ecosystems ( [[#Nagel--2017|Nagel et al., 2017]] ; [[#Lamborn--2019|Lamborn and Smith, 2019]] ) ( ''high agreement, medium evidence'' ). However, repeated and recurrent disturbances that increase recovery times can reduce the effectiveness of EbA ( ''medium confidence'' ) ( [[#Sebald--2019|Sebald et al., 2019]] ; [[#Scheidl--2020|Scheidl et al., 2020]] ).

Adaptation in mountain areas is currently constrained predominantly by soft limits related to existing social, economic and political conditions ( ''high confidence'' ) ( [[#Gioli--2014|Gioli et al., 2014]] ; [[#Sansilvestri--2016|Sansilvestri et al., 2016]] ). Progress in overcoming soft limits is currently minimal due to insufficient engagement with socioeconomic and political issues in existing adaptation ( ''medium confidence'' ) ( [[#McDowell--2019|McDowell et al., 2019]] , 2021b) ( [[IPCC:Wg2:Chapter:Chapter-8#8.4.5.3|Section 8.4.5.3]] , Cross-Chapter Box LOSS in Chapter 17). This is expected to lead to an expansion of residual risks as risk severity increases ( [[#McDowell--2021b|McDowell et al., 2021b]] ).

<div id="CCP5.4.2" class="h2-container"></div>

<span id="ccp5.4.2-challenges-opportunities-and-solution-space-for-adaptation-in-mountains"></span>