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

== CCP5.2 Observed Impacts and Adaptation in Mountain Social-Ecological Systems ==

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=== CCP5.2.1 Ecosystems and Ecosystem Services ===

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Changes in climate over short distances in mountains are reflected in large ecological gradients. AR5 reported new evidence that plant species of mid and low elevations were starting to colonise higher elevations in mountains. Since AR5, new studies have been published (e.g., [[#Steinbauer--2018|Steinbauer et al., 2018]] ; [[#Payne--2020|Payne et al., 2020]] ), including in some previously less well studied areas such as the Andes (e.g., [[#Morueta-Holme--2015|Morueta-Holme et al., 2015]] ; [[#Báez--2016|Báez et al., 2016]] ) and parts of Asia (e.g., [[#Telwala--2013|Telwala et al., 2013]] ; [[#Artemov--2018|Artemov, 2018]] ). There is now ''high confidence'' that many plant species’ distributions have shifted to higher elevations in recent decades, consistent with climatic warming (Sections 2.4.2, 10.4.2.1.1, 13.3.1.1). In recent years publications have also started to show similar trends in some animal species, including birds ( [[#Freeman--2018|Freeman et al., 2018]] ; [[#Bani--2019|Bani et al., 2019]] ; [[#Lehikoinen--2019|Lehikoinen et al., 2019]] ) and snails ( [[#Baur--2013|Baur and Baur, 2013]] ). Other climatic variables besides temperature can also affect elevational limits of species ( [[IPCC:Wg2:Chapter:Chapter-2#2.4.2|Section 2.4.2]] ) and sometimes in ways that contrast with temperature, for example increasing precipitation can allow some species to occur at lower elevations in dry climates ( [[#Crimmins--2011|Crimmins et al., 2011]] ; [[#Coals--2018|Coals et al., 2018]] ). [[#Tsai--2015|Tsai et al. (2015)]] reported large changes in the montane bird community in Taiwan, which they link to changes in weather patterns, including more severe typhoons. Changes in the amplitude and frequency of bank vole population waves in the Ilmen Nature Reserve in the Middle Urals can be linked to longer frost-free periods ( [[#Kiseleva--2020|Kiseleva, 2020]] ).

There are interactions with land use, for example a decrease in forest cover can exacerbate the effects of rising temperatures ( [[#Guo--2018|Guo et al., 2018]] ). In contrast, Bhatta et al. (2018) showed a downward shift of species assemblages in Langtang National Park, Nepal, most likely related to interactions with land use, especially reduced grazing. Where glaciers retreat, new areas become available for pioneer species to colonise and new communities to form ( [[#Cuesta--2019|Cuesta et al., 2019]] ; [[#Hock--2019|Hock et al., 2019]] ; [[#Muhlfeld--2020|Muhlfeld et al., 2020]] ). The risk of extreme events such as wildfire, drought, floods and landslips is increasing in a wide range of places as a result of climate change, and the evidence of the disturbance they cause to ecosystems has grown in recent decades (Section 2.3.1, Box CCP5.1). The impacts of such extreme events may be greater than those of incremental changes.

For species at lower elevations, mountains may represent refugia to which species can retreat. In this respect, Elsen et al. (2018) highlighted the importance of protecting areas along elevational gradients. This applies to freshwater and terrestrial habitats with mountain streams acting as potential refugia ( [[#Isaak--2016|Isaak et al., 2016]] ). In contrast, species restricted to the highest elevations are increasingly at risk, including from competition with colonising species ( [[#Britton--2016|Britton et al., 2016]] ; [[#Winkler--2016|Winkler et al., 2016]] ). Mountain-top species are often separated from potential new habitats by large areas with unsuitable climates, and tropical mountain species often have particularly narrow thermal tolerance and limited dispersal capacity ( [[#Polato--2018|Polato et al., 2018]] ).

The risks posed by non-native species may increase with climate change ( [[#Carboni--2018|Carboni et al., 2018]] ; [[#Shrestha--2018|Shrestha et al., 2018]] ; [[#Thapa--2018|Thapa et al., 2018]] ). [[#Koide--2017|Koide et al. (2017)]] found that non-native plant species on Hawaii were moving to higher elevations, whereas native species’ distributions were retracting at their lower elevational limit. [[#Dainese--2017|Dainese et al. (2017)]] found that non-native plant species spread to higher elevations approximately twice as fast as native species. Following recent climate warming, invasive ''Phyllostachys edulis'' and ''Phyllostachys bambusoides'' (Poaceae) bamboo species in Japan have shifted northwards and upslope in the last three decades ( [[#Takano--2017|Takano et al., 2017]] ). New evidence has shown that variations in microclimate, with topography and cold groundwater seeps, can provide micro-refugia small areas of locally suitable conditions where cold-adapted species can survive ( [[#Bramer--2018|Bramer et al., 2018]] ; [[#Muhlfeld--2020|Muhlfeld et al., 2020]] ) ( [[IPCC:Wg2:Chapter:Chapter-2#2.6.2|Section 2.6.2]] ). Some alpine species have thrived in recent years, and the range of microclimates may partly explain this ( [[#Rumpf--2018|Rumpf et al., 2018]] ).

Treeline elevation is linked to temperature ( [[#Paulsen--2014|Paulsen and Körner, 2014]] ) but may also be affected by water supply ( [[#Sigdel--2018|Sigdel et al., 2018]] ; [[#Lu--2021|Lu et al., 2021]] ) and land management. A recent summary of treeline shifts worldwide found that 67% of studied alpine treelines had shifted upwards while 33% remained stable (based on 142 published studies), and 88.8% of the 143 undisturbed alpine treelines across the Northern Hemisphere had shifted upwards ( [[#Hansson--2021|Hansson et al., 2021]] ; [[#Lu--2021|Lu et al., 2021]] ). Since AR5, new evidence of shifting treeline ecotones has emerged for a wide variety of species in different locations, including in Siberia ( [[#Pospelova--2017|Pospelova et al., 2017]] ), various parts of the Ural Mountains ( [[#Shiyatov--2015|Shiyatov and Mazepa, 2015]] ; [[#Zolotareva--2017|Zolotareva and Zolotarev, 2017]] ; [[#Sannikov--2018|Sannikov et al., 2018]] ), in the Canadian Rocky Mountains ( [[#Trant--2020|Trant et al., 2020]] ) and the Himalaya ( [[#Tiwari--2015|Tiwari and Joshi, 2015]] ; [[#Chakraborty--2016|Chakraborty et al., 2016]] ; [[#Gaire--2016|Gaire, 2016]] ; [[#Yadava--2017|Yadava et al., 2017]] ). Recent studies of treelines that have not or hardly shifted include those in the Himalaya ( [[#Singh--2015|Singh et al., 2015]] ; [[#Sigdel--2018|Sigdel et al., 2018]] ), eastern Tibetan Plateau ( [[#Wang--2020|Wang et al., 2020]] ) and the Andes ( [[#Lutz--2014|Lutz et al., 2014]] ). Migration rates are not proceeding as fast as warming rates, implying other processes also limit treeline ecotone response (e.g., [[#Sigdel--2020|Sigdel et al., 2020]] ; [[#Lu--2021|Lu et al., 2021]] ).

Whether treeline shifts occur, and if so at what rate, depends on a range of factors, including land use (especially livestock grazing and fire), species interactions, wildfires and climatic stress factors (wind, frost, drought, excess or shortage of snow) interacting with tree population processes (viable seed production, dispersal, seedling establishment, clonal propagation, growth, dieback, mortality). Differences in treeline shifts between north- and south-facing slopes have been demonstrated in the Rocky Mountains ( [[#Elliott--2015|Elliott and Cowell, 2015]] ). [[#Grigorieva--2018|Grigorieva and Moiseev (2018)]] showed that significant factors limiting the number of seedlings and shoots are the snow depth, the topsoil temperature dependent on it and the degree of competition from the parental tree stand and grass–shrub vegetation. In addition, land use and management exert an influence in many mountains around the world. [[#Suwal--2016|Suwal et al. (2016)]] found that elevational shifts in Himalayan silver fir in Nepal were larger when areas were protected from management. Similarly, [[#Lutz--2014|Lutz et al. (2014)]] found faster treeline shifts in the Peruvian Andes in protected areas than that in other areas, where cattle grazing and fires are more frequent. Treeline ecotones can also change independently of climate change if land use changes ( [[#Vitali--2019|Vitali et al., 2019]] ; [[#Körner--2020|Körner, 2020]] ).

Changes in community composition are also happening within ecosystem types. Duque et al. (2015) showed a change in the composition of northern Andean forests, and [[#Feeley--2013|Feeley et al. (2013)]] showed such a change in that of forests up to 2800 m in Costa Rica. In both cases the proportion of species adapted to warmer conditions increased, driven primarily by patterns of mortality, indicating that the changes in composition are mostly via range retractions, rather than range shifts or expansions. An analysis of 200 forest inventory plots in the Andes likewise indicated a widespread, though not ubiquitous, thermophilisation of tree species’ composition ( [[#Fadrique--2018|Fadrique et al., 2018]] ). Within a period of 8 years (2003–2010), significant shifts in communities of vascular plants, butterflies and birds were found in Switzerland ( [[#Roth--2014|Roth et al., 2014]] ). At lower elevations, communities of all species groups changed towards warm-dwelling species, corresponding to an average uphill shift of 8 m, 38 m and 42 m in plant, butterfly and bird communities respectively. However, rates of community change decreased with elevation in plants and butterflies, while bird communities shifted towards warm-dwelling species at all elevations ( [[#Roth--2014|Roth et al., 2014]] ).

Changes in mountain biodiversity and ecosystems have a wide range of impacts on ecosystem services and effects on people. Some mountain ecosystems, particularly those with peatlands or forests, are important carbon stores, and climate change presents a risk to these in some locations ( [[#Dwire--2018|Dwire et al., 2018]] ) (Sections 2.4.3.8, 2.4.4.4 and 2.4.4.5). [[#Palomo--2017|Palomo (2017)]] identified a wide range of threats to the lives, livelihoods and culture of mountain people as a consequence of the impacts of climate change on ecosystems. However, impacts are very heterogeneous between locations, even within the same region and ecosystem type (e.g., mountain forests in Europe) ( [[#Mina--2017|Mina et al. (2017)]] and are not necessarily all negative. In addition to changes in services, other impacts on humans from a changing climate may be mediated through species and ecosystems, for example changes in vector distribution shifting disease incidence into higher elevation areas ( [[#Escobar--2016|Escobar et al., 2016]] ).

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=== CCP5.2.2 Water and Energy ===

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==== CCP5.2.2.1 Water ====

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Water is a fundamental source of life in mountain regions; it is also a central element and ‘connector’ in coupled natural–human systems and carries diverse meanings in different sociocultural contexts, including in indigenous ontologies ( [[#Boelens--2014|Boelens, 2014]] ). In addition, water is a key component connecting upstream mountains and downstream lowlands ( [[#Salzmann--2016|Salzmann et al., 2016]] ; [[#Di%20Baldassarre--2018|Di Baldassarre et al., 2018]] ; [[#Encalada--2019|Encalada et al., 2019]] ). Mountains are of paramount importance as water towers for people living there and for around two billion people living in connected lowland areas ( [[#Immerzeel--2020|Immerzeel et al., 2020]] ; [[#Viviroli--2020|Viviroli et al., 2020]] ).

Mountain river systems are especially sensitive to and affected by climate change and continuing anthropogenic disturbance, including water pollution, hydropower development, water withdrawals for agriculture and human consumption and biodiversity loss and ecosystem changes ( ''high confidence'' ) ( [[#Honda--2016|Honda and Durigan, 2016]] ; [[#Encalada--2019|Encalada et al., 2019]] ; [[#Bissenbayeva--2021|Bissenbayeva et al., 2021]] ; [[#Chen--2021|Chen et al., 2021]] ). The effects of climate and cryosphere change in mountains on downstream water and river systems have been studied and quantified for many regions worldwide ( [[#Barnett--2005|Barnett et al., 2005]] ; [[#Huss--2011|Huss, 2011]] ; [[#Lutz--2014|Lutz et al., 2014]] ; [[#O’Neel--2015|O’Neel et al., 2015]] ; [[#Huss--2018|Huss and Hock, 2018]] ). Comprehensive approaches focusing on both water demand and supply aspects provide regionally or locally specified information on water availability, scarcity and security ( [[#Buytaert--2014|Buytaert et al., 2014]] ; [[#Drenkhan--2015|Drenkhan et al., 2015]] ; [[#Brunner--2019|Brunner et al., 2019]] ) (Chapter 4). Present and potential future hotspot regions of water scarcity that rely heavily on mountainous water sources include Central Asia, South Asia, tropical and subtropical western South America and southwestern North America ( ''robust evidence, medium agreement'' ) ( [[#Kummu--2016|Kummu et al., 2016]] ; [[#Biemans--2019|Biemans et al., 2019]] ; [[#Immerzeel--2020|Immerzeel et al., 2020]] ; [[#Viviroli--2020|Viviroli et al., 2020]] ).

Figure CCP5.2 represents different levels of dependences of lowland areas on mountain water. At a global scale, 68% of irrigated agricultural areas in lowlands depend on essential runoff contributions from the mountains. The dependence of lowland populations on essential mountain runoff contributions increased by a factor of more than three from the 1960s to the 2000s, with increases of up to ten-fold in some major river catchments ( [[#Viviroli--2020|Viviroli et al., 2020]] ).

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[[File:eb0e8abf4a6dfae6551c0ce1bf09c8ee IPCC_AR6_WGII_Figure_CCP5_002.png]]

'''Figure CCP5.2 |''' '''Dependence of land surface areas and population on mountain water resources, 1961–2050.''' Results are shown as decadal averages for lowland populations in each category of dependence on mountain water from no surplus and negligible to essential;

'''(a)''' map of global mountain regions and their differentiated importance for lowland water resources;

'''(b)''' map of lowland populations and their differentiated dependence on mountain water resources, both for the scenario combination SSP2-RCP6.0 and for the time period 2041–2050;

'''(c)''' number of lowland populations and their differentiated dependence on mountain water resources from 1960s to 2040s for three different scenario combinations (based on [[#Viviroli--2020|Viviroli et al., 2020]] ).

Many mountain regions have one or more cryosphere components (glaciers, permafrost and perennial or seasonal snow), and the mountain cryosphere is among the natural systems most sensitive to climate change worldwide ( ''high confidence'' ). The SROCC assessed a decline in all cryosphere components due to climate change over recent decades, i.e., for low-elevation snow cover ( ''high confidence'' ), permafrost ( ''high confidence'' ) and glaciers ( ''very high confidence'' ) ( [[#Hock--2019|Hock et al., 2019]] ). More recent studies using globally more complete data sets show a considerably higher glacier mass loss (267 ±16 Gt yr -1 ) for 2000–2019 as compared to a ( ''very likely'' [[#footnote-000|2]] ) range of 123 ±24 Gt yr -1 for 2006–2015 in SROCC, with a mass loss acceleration of 48 ±16 Gt yr -1 per decade over 2000–2019 ( [[#Hugonnet--2021|Hugonnet et al., 2021]] ). Assessment conclusions in SROCC found with ''high confidence'' that glacier shrinkage and snow cover changes over the past two decades have led to changes in the amount and timing of runoff in many mountain regions ( [[#Hock--2019|Hock et al., 2019]] ).

The effects of climate and environmental changes in upstream areas on downstream water quantity and quality, including nutrient, pollutant, heavy metals and sediment flux, have been assessed in only a limited number of catchments ( [[#Rakhmatullaev--2009|Rakhmatullaev et al., 2009]] ; [[#Dong--2015|Dong et al., 2015]] ; [[#Milner--2017|Milner et al., 2017]] ; [[#Ilyashuk--2018|Ilyashuk et al., 2018]] ; [[#Lane--2019|Lane et al., 2019]] ; [[#Li--2020|Li et al., 2020]] ; [[#Chen--2021|Chen et al., 2021]] ). Groundwater contributions to streamflow are highly variable in mountains but can be substantial (up to 70 to 80% or more) during low-flow periods ( [[#Frisbee--2011|Frisbee et al., 2011]] ; [[#Baraer--2015|Baraer et al., 2015]] ; [[#Gordon--2015|Gordon et al., 2015]] ; [[#Käser--2016|Käser and Hunkeler, 2016]] ; [[#Somers--2019|Somers et al., 2019]] ). Groundwater may provide some resilience to loss of melt water from glacier and snow decline, but in the longer term groundwater recharge and contribution to streamflow are expected to decrease with ongoing climate change ( ''medium confidence'' ) ( [[#Somers--2020|Somers and McKenzie, 2020]] ). In some mountain regions (e.g., in the Himalaya), springs are a particularly important source of water where large populations depend on them. Observations indicate a reduction of water provision from springs in recent years in the Himalaya, caused by multiple causal factors (human interventions, climatic) ( [[IPCC:Wg2:Chapter:Chapter-10#10.4.4|Section 10.4.4]] .).

Both small-scale interventions (e.g., livestock grazing in sensitive high-elevation wetlands) and high-investment interventions (e.g., hydropower dams and plants) in upstream regions can strongly affect water availability, river connectivity, biodiversity and catchment management ( [[#Anderson--2018|Anderson et al., 2018]] ; [[#Ramsar%20Convention%20on%20Wetlands--2018|Ramsar Convention on Wetlands, 2018]] ; [[#Encalada--2019|Encalada et al., 2019]] ) and are often contested and have led to conflict ( ''medium evidence, high agreement'' ) ( [[#Drenkhan--2015|Drenkhan et al., 2015]] ; [[#French--2015|French et al., 2015]] ). Climate change often exacerbates tensions or conflicts between different users over water at local, national and transboundary or regional scales, and many tensions and social or political conflicts are documented, especially in seasonally dry regions, where large power inequalities exist among users, where clear and established regulations are lacking, and especially in transboundary settings (e.g., Central Asia, Hindu Kush Himalaya [HKH], Andes) ( [[#Carey--2014|Carey et al., 2014]] ; [[#Bocchiola--2017|Bocchiola et al., 2017]] ; [[#Yapiyev--2017|Yapiyev et al., 2017]] ; [[#Hock--2019|Hock et al., 2019]] ; [[#Mukherji--2019|Mukherji et al., 2019]] ).

Water plays a fundamental role in climate change adaptation in mountains. A majority of documented adaptation efforts in mountain regions address water-related aspects (precipitation variability and extremes, including drought, water availability, floods) ( ''high confidence'' ) ( [[#McDowell--2019|McDowell et al., 2019]] , 2020). This is a robust finding across different mountain regions and adaptation project and programme types and is in line with findings for cryosphere-change-related adaptation, as reported in SROCC ( [[#Hock--2019|Hock et al., 2019]] ). Water also plays a role in adaptation in other sectors, such as agriculture, disaster management, and tourism and recreation ( [[#McDowell--2019|McDowell et al., 2019]] ). There is ''high confidence'' that water conservation efforts, including restoration and protection of particularly vulnerable areas (e.g., wetlands) and increase in efficiency in water use, are robust, low-regret adaptation measures.

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==== CCP5.2.2.2 Energy ====

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Increasing temperatures and variability in precipitation and river flow affect energy availability and use in mountain regions. Mountain peoples, more so than national or global populations, are dependent on local sources of energy, accentuating climate adaptation cost and barriers ( ''medium evidence, high agreement'' ), while also offering opportunities for mountain-specific solutions ( ''medium evidence, high agreement'' ). In mountain regions, inadequate infrastructure ( [[#Tiwari--2018|Tiwari et al., 2018]] ), remoteness and reliance on traditional forms of energy that may be difficult to diversify ( [[#Dhakal--2019|Dhakal et al., 2019]] ) exacerbate the impacts of climate change on energy use and demand.

A review of the renewable energy transition in the context of adaptation across global mountain regions, including hydropower, wind, solar and biomass, shows that observed climate change impacts on these energy sources include altered seasonality, timing as related to snow and glacial melt runoff (30.9% of analysed cases), variable or declining precipitation and runoff (26.4%), increased flooding (15.5%), altered wind patterns (8.2%) and other/unspecified effects (19.1%) ( [[#Scott--2019|Scott et al., 2019]] ). The combined effects of climate change, hydropower development and further anthropogenic effects in upstream mountain basins have increased and are expected to further negatively affect several aspects of ecosystem functioning and water security (e.g., negative effects on river geometry, water chemistry, sediment transport, fish composition and migration) ( ''high confidence'' ) ( [[#Anderson--2018|Anderson et al., 2018]] ; [[#Encalada--2019|Encalada et al., 2019]] ; [[#Lepcha--2021|Lepcha et al., 2021]] ).

With respect to hydropower, mountains play a unique role in the production of renewable energy for large downstream populations, but it also comes with important trade-offs affecting mountain ecosystems and populations ( ''high confidence'' ) ( [[#Farinotti--2019|Farinotti et al., 2019]] ; [[#Viviroli--2020|Viviroli et al., 2020]] ; [[#Vaidya--2021|Vaidya et al., 2021]] ). Climate change requires adaptation in the hydropower sector; for instance, some advocate for increased water storage in dams and the importance of mountains for pumped hydropower storage systems ( [[#Gurung--2016|Gurung et al., 2016]] ; [[#Hunt--2020|Hunt et al., 2020]] ), while others emphasise adaptive water management ( [[#Gaudard--2014|Gaudard et al., 2014]] ; [[#Caruso--2017b|Caruso et al., 2017b]] ). An example is the multi-purpose use of water strategies where water management storage is designed to accommodate different uses, including hydropower, agriculture and flood risk reduction ( [[#Haeberli--2016a|Haeberli et al., 2016a]] ; [[#Drenkhan--2019|Drenkhan et al., 2019]] ) ( [[IPCC:Wg2:Chapter:Chapter-12#12.6.3|Section 12.6.3]] ). Hydropower is also especially vulnerable to glacier and snow decline ( [[#Schaefli--2019|Schaefli et al., 2019]] ) and is subject to risks from extreme events ( [[#Rangecroft--2013|Rangecroft et al., 2013]] ; [[#Schwanghart--2016|Schwanghart et al., 2016]] ; [[#Mishra--2020|Mishra et al., 2020]] ; [[#Shugar--2021|Shugar et al., 2021]] ), social and political opposition ( [[#Ahlers--2015|Ahlers et al., 2015]] ; [[#Díaz--2017|Díaz et al., 2017]] ) and the resulting financial uncertainty for hydropower investors. There is still ''limited evidence'' on how climate change impacts wind, solar and biomass energy production and their use.

Overall, synergies between adaptation to climate change and renewable energy transition can be successfully generated where benefit-sharing improves local involvement and support, adaptive capacity is enhanced, local health and livelihoods supported, Sustainable Development Goals (SDGs) met, environmental justice considered and sustainable mountain development pursued ( ''high agreement, medium evidence'' ).

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=== CCP5.2.3 Food, Fibre and Other Mountain Ecosystem Products ===

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There is ''high confidence'' that climate change is largely negatively impacting food, fibre and other ecosystem products, including agriculture ( [[#Porter--2014|Porter et al., 2014]] ; [[#Ingxay--2015|Ingxay et al., 2015]] ; [[#Upgupta--2015|Upgupta et al., 2015]] ; [[#Chirwa--2017|Chirwa et al., 2017]] ; [[#Rojas-Downing--2017|Rojas-Downing et al., 2017]] ; [[#Chitale--2018|Chitale et al., 2018]] ; [[#Pretzsch--2018|Pretzsch et al., 2018]] ; [[#Barberán--2019|Barberán et al., 2019]] ; [[#Sultan--2019|Sultan et al., 2019]] ; [[#Huang--2020|Huang and Hao, 2020]] ; [[#Godde--2021|Godde et al., 2021]] ), and ecosystem services ( [[#Grêt-Regamey--2020|Grêt-Regamey and Weibel, 2020]] ) across many different mountainous regions, for example in Africa ( [[#Bondé--2019|Bondé et al., 2019]] ; [[#Musakwa--2020|Musakwa et al., 2020]] ), Asia ( [[#Guo--2018|Guo et al., 2018]] ; [[#Sunderland--2020|Sunderland and Vasquez, 2020]] ), Europe ( [[#Nair--2019|Nair, 2019]] ), North America ( [[#Hupp--2015|Hupp et al., 2015]] ; [[#Prevéy--2020|Prevéy et al., 2020]] ) and South America ( [[#Herman-Mercer--2020|Herman-Mercer et al., 2020]] ) (Sections 5.4, 5.4.1, 5.5.1, 5.6.2, 5.7, 5.11.1.1).

Ecosystem products are vital to support the livelihoods and economic prospects for communities living in and around mountains (Figure CCP5.3). For instance, collection and trade of caterpillar fungus contributed to 53.3–64.5% annual household cash income in Nepal ( [[#Shrestha--2014|Shrestha and Bawa, 2014]] ; [[#Shrestha--2019|Shrestha et al., 2019]] ); 40–80% in Bhutan ( [[#Thapa--2018|Thapa et al., 2018]] ) and 60–78% in Uttarakhand, India ( [[#Laha--2018|Laha et al., 2018]] ; [[#Yadav--2019|Yadav et al., 2019]] ) ( [[IPCC:Wg2:Chapter:Chapter-5#5.7.1|Section 5.7.1]] ). Livelihood support from ecosystem products in southern Malawi ( [[#Pullanikkatil--2020|Pullanikkatil et al., 2020]] ), southwestern Ethiopian mountains ( [[#Nischalke--2017|Nischalke et al., 2017]] ), Southern China ( [[#Min--2017|Min et al., 2017]] ), Himalayan mountains ( [[#Nepal--2018|Nepal et al., 2018]] ) and South Africa ( [[#Ngwenya--2019|Ngwenya et al., 2019]] ) has been reported. Additionally, the sacredness of mountains in different religions and cultures is widely acknowledged ( [[#Ceruti--2019|Ceruti, 2019]] ; [[#Benedetti--2021|Benedetti et al., 2021]] ).

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[[File:90e411e2a4b31b3de8fcf9c21f5281d1 IPCC_AR6_WGII_Figure_CCP5_003.png]]

'''Figure CCP5.3 |''' '''Impact of climate change on mountain social-ecological systems, including ecosystem services and products, livelihoods of mountain people and examples of adaptation options to address direct and indirect impacts.'''

Climate change and its associated impacts on multiple ecosystem services and related products (timber production, carbon sequestration, biodiversity and protection against natural hazards) have been observed across European mountains, for example in the central Iberian Mountains (Spain), Western and Eastern Alps (France, Austria) and Dinaric Mountains (Slovenia) ( [[#Mina--2017|Mina et al., 2017]] ). [[#Dumont--2015|Dumont et al. (2015)]] demonstrated that climate change negatively affects forage nitrogen (N) content by 8% but increases total non-structural carbohydrate content by 25% in European mountains. Positive impacts have been reported on mushroom productivity in the mountains of Spain ( [[#Karavani--2018|Karavani et al., 2018]] ) ( [[IPCC:Wg2:Chapter:Chapter-5#5.7.3|Section 5.7.3.3]] ), yet negative impacts have been reported on the ''Ophiocordyceps'' in the Himalayan region ( [[#Hopping--2018|Hopping et al., 2018]] ), as well as on apple production in Himachal Pradesh, India, which declined by 9.4 t per hectare in the past two decades ( [[#Das--2021|Das, 2021]] ). Shifts in the richness of crop wild relatives from south to north and an increase in the numbers of threatened taxa with an increase of 1.5°C and 3°C temperature rise have been observed in European mountains ( [[#Phillips--2017|Phillips et al., 2017]] ).

Medicinal and aromatic plants and their secondary metabolites are also observed to be affected by climate change ( ''medium confidence'' ) ( [[#Das--2016|Das et al., 2016]] ; [[#Zhang--2019a|Zhang et al., 2019a]] ) ''.'' Phenological changes like early flowering and reduced vegetative phase are negatively affecting the productivity of such plants ( [[#Harish--2012|Harish et al., 2012]] ; [[#Gaira--2014|Gaira et al., 2014]] ; [[#Maikhuri--2018|Maikhuri et al., 2018]] ). While increasing atmospheric temperature and CO 2 are reported to improve the biomass of ''Gynostemma pentaphyllum'' ( [[#Chang--2016|Chang et al., 2016]] ) ( [[IPCC:Wg2:Chapter:Chapter-5#5.7.3|Section 5.7.3.3]] ), they adversely affect its antioxidant compounds/activity, health-promoting properties and phytochemical content ( [[#Gairola--2010|Gairola et al., 2010]] ; [[#Das--2016|Das et al., 2016]] ; [[#Kumar--2020|Kumar et al., 2020]] ). Experimental trials have shown that when medicinal plants are stressed by drought, phytochemical content increases, either by a decrease in biomass or by an increase in the actual production of metabolites ( ''medium confidence'' ) ( [[#Selmar--2013|Selmar and Kleinwächter, 2013]] ; [[#Al-Gabbiesh--2015|Al-Gabbiesh et al., 2015]] ). The strong effects of climatic and non-climatic factors have been observed to affect the distribution of selected medicinal plant species in northern Thailand ( [[#Tangjitman--2015|Tangjitman et al., 2015]] ), as well as in Egypt, sub-Saharan Africa, Spain, Central Himalaya, China and Nepal, with some species at risk of extinction ( [[#Munt--2016|Munt et al., 2016]] ; [[#Yan--2017|Yan et al., 2017]] ; [[#Brunette--2018|Brunette et al., 2018]] ; [[#Chitale--2018|Chitale et al., 2018]] ; [[#Zhao--2018|Zhao et al., 2018]] ; [[#Applequist--2020|Applequist et al., 2020]] ). Negative climate-related impacts on the distribution range of 41 medicinal plant species have been predicted for Spanish and Asian mountains ( [[#Munt--2016|Munt et al., 2016]] ) ( [[IPCC:Wg2:Chapter:Chapter-5#5.7.3|Section 5.7.3.3]] ), as has a decreasing size of fruits of ''Myrica esculenta'' in the Himalaya ( [[#Shah--2016|Shah and Tewari, 2016]] ).

<div id="box-ccp5.1" class="h2-container box-container"></div>

<span id="box-ccp5.1-wildfires-and-mountain-ecosystems"></span>
=== Box CCP5.1 | Wildfires and Mountain Ecosystems ===

<div id="h2-5-siblings" class="h2-siblings"></div>

''Mountain ecosystems have long been known to be highly sensitive to the direct impacts of climatic warming and drying ( [[#Beniston--1994|Beniston et al., 1994]] ; [[#Nogués-Bravo--2009|Nogués-Bravo, 2009]] ; [[#Gottfried--2012|Gottfried et al., 2012]] ; [[#Guisan--2019|Guisan et al., 2019]] ). Furthermore, wildfires in these ecosystems, as in many others (Sections 2.4.4.2 and 2.5.3.2), are also expected to increase ( [[#Abatzoglou--2019|Abatzoglou et al., 2019]] ). This is because the occurrence and severity of fire are governed by four fundamental processes that are intricately linked to climate: 1) fuel biomass growth, 2) fuel moisture and type, 3) ignition source and 4) favourable weather conditions for fire spread ( [[#Bradstock--2010|Bradstock, 2010]] ).''

''In temperate and tropical mountain ecosystems, increases in fire activity are potentially linked to changing climate on most continents, including Europe ( [[#Dupire--2017|Dupire et al., 2017]] ), North America ( [[#Westerling--2016|Westerling, 2016]] ; [[#Halofsky--2020|Halofsky et al., 2020]] ; [[#Burke--2021|Burke et al., 2021]] ), South America ( [[#Román-Cuesta--2014|Román-Cuesta et al., 2014]] ), Africa ( [[#Hemp--2005|Hemp, 2005]] ), Asia ( [[#Tian--2014|Tian et al., 2014]] ) and Australia ( [[#Bradstock--2014|Bradstock et al., 2014]] ; [[#Abram--2021|Abram et al., 2021]] ). In these ecosystems, fire frequency, severity and extent (i.e., the fire regime) are increasing because of climate-induced impacts on fuel moisture ( [[#Gergel--2017|Gergel et al., 2017]] ; [[#Littell--2018|Littell et al., 2018]] ), vegetation composition (i.e., fuel types) ( [[#Camac--2017|Camac et al., 2017]] ; [[#Prichard--2017|Prichard et al., 2017]] ; [[#Zylstra--2018|Zylstra, 2018]] ), fire-conducive weather patterns and the length of fire seasons ( [[#Westerling--2016|Westerling, 2016]] ; [[#Fill--2019|Fill et al., 2019]] ; [[#Di%20Virgilio--2020|Di Virgilio et al., 2020]] ).''

''Fire in mountain ecosystems alters many ecological processes and ecosystem services across all elevational zones, from foothill montane forests to high-elevation alpine (treeless) zones ( [[#Turner--2003|Turner et al., 2003]] ; [[#Williams--2008|Williams et al., 2008]] ; [[#Oliveras--2014|Oliveras et al., 2014]] , 2018; [[#Rocca--2014|Rocca et al., 2014]] ). However, the magnitude of short-term and long-term fire impacts depends on the degree of novelty of future fire regimes and the capacity of species to adapt to change ( [[#Camac--2017|Camac et al., 2017]] , 2021; [[#Archibald--2018|Archibald et al., 2018]] ).''

''Montane and sub-alpine ecosystems have variable ecological responses to fire that are ultimately influenced by long-term, historical fire regimes and the evolutionary forces that have governed post-fire regeneration strategies of the biota. Two contrasting strategies in temperate forests are illustrated here. SE Australian mountain ash ('' ''Eucalyptus regnans'' '') forests are adapted to a high-severity fire regime, consisting of infrequent (&gt;100 years), large stand-replacing wildfires ( [[#Bowman--2016|Bowman et al., 2016]] ). Mountain ash is a long-lived obligate seeder but is slow to reach reproductive maturity (&gt;20 years) ( [[#Bowman--2016|Bowman et al., 2016]] ). As such, natural post-fire regeneration takes decades to centuries to recover to pre-fire conditions, and if fire reoccurs before reproductive maturity is reached, the species can be eliminated. By contrast, ponderosa pine ('' ''Pinus ponderosa'' '') forests of the SW United States have evolved with a low- or mixed-severity fire regime, where fire is frequent (5–25 years), of low intensity, less likely to kill dominant stands and, thus, allow faster post-fire recovery ( [[#Prichard--2017|Prichard et al., 2017]] ). However, post-fire recovery times in this ecosystem are also becoming longer due to a century of effective fire suppression, shifting the fire regime to one which is more infrequent, of high intensity, extensive and stand replacing ( [[#Prichard--2017|Prichard et al., 2017]] ).''

''Above the treeline, fire is less common than in foothill forests. Post-fire recovery times also tend to be shorter ( [[#Williams--2008|Williams et al., 2008]] ; [[#Camac--2013|Camac et al., 2013]] ; [[#Verrall--2019|Verrall and Pickering, 2019]] ) because of the dual influences of low flammability traits coupled with the fact that most alpine plant species exhibit strong resprouting strategies that have evolved in response to harsh climate conditions ( [[#Körner--2003|Körner, 2003]] ). However, fires in alpine treeless landscapes can still have long-term and catastrophic impacts on fire-sensitive vegetation types such as groundwater-dependent wetlands dominated by hygrophilous plants and peat soils ( [[#De%20Roos--2018|De Roos et al., 2018]] ). Similar impacts can be severe on long-lived, slow-growing vegetation such as coniferous heathlands ( [[#Bowman--2019|Bowman et al., 2019]] ) and highly restricted and threatened fauna (e.g., mountain pygmy possum) that depend on these plant communities ( [[#Gibson--2018|Gibson et al., 2018]] ). Such fires have even been found to significantly impact sub-alpine treeline mortality rates ( [[#Fairman--2017|Fairman et al., 2017]] ) and in some cases have resulted in treelines shifting to lower elevations (e.g., [[#Hemp--2005|Hemp, 2005]] ).''

The long-term implications of a warmer global climate, coupled with more frequent and/or severe fires in mountain ecosystems, are expected to be transformative for mountain biota. Fire-sensitive montane forests, such as Australia’s alpine ash ( ''Eucalyptus delegatensis'' ), are expected to become highly susceptible to population collapse and local extinction as intervals between fire events contract and become too short for species to reach reproductive maturity ( [[#Bowman--2014|Bowman et al., 2014]] ; [[#Enright--2015|Enright et al., 2015]] )—an impact that will ''likely'' be further exacerbated by recruitment failure caused by post-fire drought and moisture deficiencies ( [[#Davies--2019|Davies et al., 2019]] ; [[#Halofsky--2020|Halofsky et al., 2020]] ; [[#Rodman--2020|Rodman et al., 2020]] ). Fire and climate change are also ''likely'' to act synergistically in mountainous ecosystems, via positive feedbacks that increase fire frequency by changing vegetation composition to more flammable fuel types, thereby increasing landscape susceptibility to future fire ( [[#Camac--2017|Camac et al., 2017]] ; [[#Tepley--2018|Tepley et al., 2018]] ; [[#Zylstra--2018|Zylstra, 2018]] ; [[#Lucas--2021|Lucas and Harris, 2021]] ). More frequent fires in these ecosystems will also exacerbate native and exotic species invasions ( [[#Catford--2009|Catford et al., 2009]] ; [[#McDougall--2011|McDougall et al., 2011]] ; [[#Gottfried--2012|Gottfried et al., 2012]] ; [[#Kueffer--2013|Kueffer et al., 2013]] ), faunal population declines ( [[#Ward--2020|Ward et al., 2020]] ), poor air quality ( [[#de%20la%20Barrera--2018|de la Barrera et al., 2018]] ; [[#Burke--2021|Burke et al., 2021]] ) and soil erosion and landslide risk ( [[#de%20la%20Barrera--2018|de la Barrera et al., 2018]] ) and reduce freshwater catchment volumes and quality ( [[#Rust--2018|Rust et al., 2018]] ; [[#Niemeyer--2020|Niemeyer et al., 2020]] ), all of which will impact negatively on human health and well-being ( [[#Ebi--2021|Ebi et al., 2021]] ).

''Taken together, this evidence suggests that a significant risk exists of wildfire exacerbating other impacts of climate change on already vulnerable ecosystems in many mountain regions ('' ''medium confidence'' '').''

<div id="CCP5.2.4" class="h2-container"></div>

<span id="ccp5.2.4-cities-settlements-and-key-infrastructure"></span>
=== CCP5.2.4 Cities, Settlements and Key Infrastructure ===

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Mountain settlements and people are globally distributed and represent a significant proportion of the total global population that is exposed to the effects of climate change (Section CCP5.1, SMCCP5.1). Cities with one or several million inhabitants located in mountainous environments or at high elevations are predominantly found in Latin America (e.g., El Alto and La Paz, Bolivia; Quito, Ecuador; Mexico City, Mexico; and Bogota, Colombia), Asia (e.g., Kabul, Afghanistan; Kathmandu, Nepal; Srinagar and Dehradun, India; Peshawar and Quetta, Pakistan; and Xining and Kunming, China) and Africa (e.g., Harare, Zimbabwe; and Addis Ababa, Ethiopia) ( [[#Wang--2018|Wang and Lu, 2018]] ; [[#Balderas%20Torres--2021|Balderas Torres et al., 2021]] ; [[#Ehrlich--2021|Ehrlich et al., 2021]] ). Mountain regions are also host to many settlements with fewer than 500,000 inhabitants ( [[#Alfthan--2016|Alfthan et al., 2016]] ). In many cases, particularly in developing countries, portions of the population also reside in informal and low-income settlements ( [[#French--2021|French et al., 2021]] ), where rates of poverty and inequality exacerbate people’s vulnerability and exposure to climate-related hazards such as landslides (Alfthan et al. 2018) (Section CCP5.2.5.1), environmental pollution or even pandemic diseases ( [[#Marazziti--2021|Marazziti et al., 2021]] ).

In many mountain regions, particularly in developing countries, the increasing urban population has put considerable pressure on water services and basic amenities for urban dwellers ( [[#Singh--2021|Singh et al., 2021]] ), for example in cities such as La Paz ( [[#Kinouchi--2019|Kinouchi et al., 2019]] ), which are regions already under pressure due to the negative effects of climate change, coupled with poor water availability and governance (Chapter 4; CCP5.2.2.1; FAQ CCP5.1; Hock et al. 2019). In many areas of the HKH region, water demand far exceeds municipal supply, and people cope with water insecurity in a variety of ways ( [[#Bharti--2020|Bharti et al., 2020]] ; [[#Sharma--2020|Sharma et al., 2020]] ; [[#Singh--2020|Singh et al., 2020]] ), such as by resorting to interbasin water transfers and deep pumping, to supply their water needs ( [[#Ojha--2020|Ojha et al., 2020]] ). Additionally, influxes of migrants, tourists and retirees, combined with the growth of the incumbent population, place considerable stress on urban infrastructures that must supply adequate clean water and provide for sewage disposal (Prakash and Molden, 2020), which is also observable in other regions (Chapter 4; [[IPCC:Wg2:Chapter:Chapter-6#6.4.7|Section 6.4.7]] ; Case Study 6.1 in Chapter 6). Energy provision in and around mountain settlements is another key sector affected by climate-related impacts ( [[#Hock--2019|Hock et al., 2019]] ; CCP5.2.2.2), which bears relevance for the adaptation prospects for urban mountain settlements ( ''medium confidence'' ).

<div id="CCP5.2.5" class="h2-container"></div>

<span id="ccp5.2.5-mountain-communities-livelihoods-health-and-well-being"></span>
=== CCP5.2.5 Mountain Communities, Livelihoods, Health and Well-Being ===

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People living in and around mountain regions strongly depend for their livelihoods, health and well-being on the ecosystem functions, services and resources available in these areas. Overall, subsistence agriculture and livestock remain key sources of livelihood in many mountain regions ( [[#FAO--2019|FAO, 2019]] ), with non-agricultural income sources such as remittances, small businesses, medicinal plants, wage labour and tourism also contributing to these economies ( [[#Montanari--2014|Montanari and Koutsoyiannis, 2014]] ; [[#Palomo--2017|Palomo, 2017]] ; [[#Minta--2018|Minta et al., 2018]] ). This section provides an illustrative overview of key reported observed impacts of climate change on mountain communities and adaptation responses (Table CCP5.1), as well as impacts on livelihood activities and economic sectors such as agriculture and pastoralism and tourism and recreation (Table CCP5.2), reported since AR5.

Other sections in this CCP provide detailed assessments that synthesise impacts associated with the detection of climate change and the attribution of those impacts to anthropogenic climate change (CCP5.2.7), projected impacts and key risks (CCP5.3) and adaptation responses to reduce those key risks (CCP5.4.1).

'''Table CCP5.1 |''' Overview of key observed impacts and adaptation on mountain communities—livelihoods and poverty; migration, habitability and displacement; health and well-being.

{| class="wikitable"
|-
! colspan="2"| '''Overview of key observed impacts on mountain communities and adaptation responses'''

! '''References and relevant AR6 WGII sections'''

|-
| colspan="3"| ''Mountain livelihoods and poverty''

|-
| Impacts

| * In some mountain regions, the incidence of poverty can be higher compared to other areas, with observed impacts of climate change intensifying the deterioration of socioeconomic conditions that support livelihoods, thereby exacerbating already existing conditions of non-climate-related vulnerabilities and livelihood insecurity ( ''medium confidence'' ).

| [[#Gioli--2019|Gioli et al. (2019)]] , [[#Tiwari--2012|Tiwari and Joshi (2012)]] , [[#Rasul--2015|Rasul and Hussain (2015)]] , [[#Hussain--2019|Hussain et al. (2019)]] , [[#McDowell--2012|McDowell and Hess (2012)]] , FAO (2015, 2019), [[#Shrestha--2015|Shrestha et al. (2015)]] , [[#Motschmann--2020a|Motschmann et al. (2020a)]] , [[IPCC:Wg2:Chapter:Chapter-8#8.3|Section 8.3]]

|-
| Responses and adaptation

| * Diversification of livelihoods through integration of drought-resilient livestock and crops and changes in farming practices (i.e., water management or migration of crops from lowland to highland) with some shifting to non-agricultural livelihood options, reported for cases such as in the HKH, the Andes, Rwenzori Mountains of Uganda and Simien Mountains of Ethiopia.

| Ashraf et al. (2014), Hussain et al. (2016a), [[#Skarbø--2016|Skarbø and VanderMolen (2016)]] , [[#Nkuba--2020|Nkuba et al. (2020)]] , Yohannes et al. (2020), CCP5.4.1

|-
| colspan="3"| ''Migration, habitability and displacement''

|-
| rowspan="4"| Impacts

| * There is growing evidence of links between climate change impacts and migration and mobility through a complex web of causal links ( ''medium confidence'' ). In mountain contexts, migration and mobility are indirectly impacted by climate change through adverse effects on mountain livelihoods that are dependent on mountain ecosystem services.

| [[#Wrathall--2014|Wrathall et al. (2014)]] , Hunter et al. (2015), Brandt et al. (2016), [[#Mastrorillo--2016|Mastrorillo et al. (2016)]] , [[#Gautam--2017|Gautam (2017)]] , [[#Sagynbekova--2017|Sagynbekova (2017)]] , [[#Cattaneo--2019|Cattaneo et al. (2019)]] , [[#Maharjan--2020|Maharjan et al. (2020)]]

|-
| * Extreme events are resulting in temporary and, in some cases, permanent displacement of populations in mountains ( ''medium confidence'' ), with hazards such as floods and mass movement (avalanche, flood, landslide) leading to population displacements (e.g., in Afghanistan, Pakistan, Peru, Thailand and Uganda).

| Iribarren Anacona et al. (2015), [[#Stäubli--2018|Stäubli et al. (2018)]] , [[#IDMC--2020|IDMC (2020)]] , [[#Wang--2020|Wang et al. (2020)]]

|-
| * Cases of entire settlements either abandoned or relocated due to prolonged slow onset events such as water shortage, drought and heat stress have been reported.

| Mueller et al. (2014), [[#Nawrotzki--2016|Nawrotzki and DeWaard (2016)]] , [[#Prasain--2018|Prasain (2018)]]

|-
| * In contrast, place attachment is increasingly cited as one of the reasons for the immobility choices for some people. However, in some cases, vulnerability to climatic events contributes to the in-migration decisions of vulnerable populations exposed to hazards from downstream to upland areas.

| [[#Adams--2016|Adams (2016)]] , [[#Dandy--2019|Dandy et al. (2019)]] , Khanian et al. (2019), Islam et al. (2020)

|-
| Responses and adaptations

| * Migration, in turn, is often cited as a risk management strategy, where migration can lead to the diversification of livelihood options, improves access to information and resources and expands social networks, all of which can support households in their capacity to adapt to climate change impacts.
* Migration is often gendered, with men migrating and leaving women to manage households at origin. Women’s capacities are often constrained due to institutional barriers and social norms, resulting in low adaptive capacity and increased vulnerability to hazards. Capacity-building interventions strengthen adaptation capacity and links to access institutional support ( ''medium confidence'' ).

| [[#Banerjee--2018|Banerjee et al. (2018)]] , [[#Banerjee--2019|Banerjee et al. (2019)]] , [[#Siddiqui--2019|Siddiqui et al. (2019)]] , [[#Maharjan--2020|Maharjan et al. (2020)]] , [[#Maharjan--2021|Maharjan et al. (2021)]]

|-
| colspan="3"| ''Health and well-being''

|-
| rowspan="5"| Impacts

| * Direct links between climate change and health in mountain regions are reported in terms of physical injury or fatality due to exposure to climate-related hazards such as floods or landslides or to vector-borne diseases such as malaria or dengue fever reported at higher elevations with warming temperatures ( ''medium confidence'' ), such as in Mexico, Nepal, Ethiopia and Colombia.

| Dantés et al. (2014), [[#Siraj--2014|Siraj et al. (2014)]] , Dhimal et al. (2015), [[#Wu--2016|Wu et al. (2016)]] , [[#Equihua--2017|Equihua et al. (2017)]] , [[#Alfthan--2018|Alfthan et al. (2018)]] , Gilgel et al. (2019), Chapter 7

|-
| * Indirect impacts on health of climate change are linked to water-borne diseases and pathogens associated with floods and droughts.

| Table 7.6

|-
| * While reports on the ongoing challenges associated with the COVID-19 pandemic are emerging in relation to their compounding impacts on adaptive capacities, there is ''limited evidence'' to assess those effects with respect to other climate-related impacts on health.

| [[#Baiker--2020|Baiker et al. (2020)]] , Cross-Chapter Box COVID in Chapter 7

|-
| * Mental health issues associated with climate-related impacts have been reported with respect to climate anxiety and ecological grief and their effects on the well-being of individuals. For example, the grief and loss associated with changes in glaciated landscapes, such as the ‘death’ of the Okjökull glacier in Iceland. However, there is ''limited evidence'' on mountain-specific cases and experiences that would allow for an assessment of the broader and longer-term impacts on mental health associated with a changing climate in mountains.

| Trombley et al. (2017), [[#Cunsolo--2018|Cunsolo and Ellis (2018)]] , [[#Clayton--2020|Clayton (2020)]] , [[#Sideris--2020|Sideris (2020)]]

|-
| * Other heightened vulnerability to climate-related impacts on health and well-being are also experienced by specific groups, for example Sami pastoralists facing changes in mountain snow cover that negatively affect their reindeer herding, a key activity for their identity and spiritual health.

| Furberg et al. (2011), [[IPCC:Wg2:Chapter:Chapter-7#7.1.7.2|Section 7.1.7.2]]

|-
| Responses and adaptations

| * Approximately a fifth of observed adaptations reported in the GAMI mountain reanalysis address health and well-being as an aspect of vulnerability. This includes raising communities’ awareness of and coping strategies for climate-change-induced health issues.

| [[#Furu--2013|Furu and Van (2013)]] , Section CCP5.4.1

|}

'''Table CCP5.2 |''' Overview of key observed impacts and adaptation on select livelihood activities and economic sectors—mountain agriculture and pastoralism, and tourism and recreation.

{| class="wikitable"
|-
! colspan="2"| '''Overview of key observed impacts and adaptation on select livelihood activities and economic sectors'''

! '''References and relevant AR6 WGII sections'''

|-
| colspan="3"| ''Mountain agriculture and pastoralism''

|-
| rowspan="8"| Impacts

| * Changes in temperature and seasonal precipitation patterns affect the timing and availability of water for agricultural activities ( ''high confidence'' ), for example in the Bolivian Andes; the Andean-Amazon foothills of Colombia, Ecuador and Peru; the High Atlas of Morocco; HKH; and the Golestan province of Iran.

| [[#Rangecroft--2013|Rangecroft et al. (2013)]] , [[#Kaboosi--2017|Kaboosi and Kordjazi (2017)]] , [[#Hussain--2018|Hussain et al. (2018)]] , [[#Kalbali--2019|Kalbali et al. (2019)]] , [[#Zkhiri--2019|Zkhiri et al. (2019)]] , [[#Beltrán-Tolosa--2020|Beltrán-Tolosa et al. (2020)]] , [[#Torres-Batlló--2020|Torres-Batlló and Martí-Cardona (2020)]]

|-
| * Changes in temperature and seasonal precipitation patterns are reported to affect nutrient depletion of soils and increased incidence of pest attacks in crops (e.g., in cases in the HKH and in Peru); however, there is generally ''limited evidence'' on directs links specifically to climate-related changes in mountain regions.

| [[#Oliver-Smith--2014|Oliver-Smith (2014)]] , [[#Hussain--2016b|Hussain et al. (2016b)]]

|-
| * Climate-induced hazards, such as erratic precipitation (rain, snow and hail), floods, droughts and landslides, have negatively affected the stable supply and transport of agricultural products in and out of remote mountain areas, such as in the Peruvian Altiplano and HKH.

| [[#Hussain--2016b|Hussain et al. (2016b)]] , [[#Gonzales-Valero--2018|Gonzales-Valero (2018)]] , Thapa and Hussain (2020)

|-
| * Warming temperatures and changes in the timing of seasons and frost conditions needed for seeding certain tree crops impact lower-elevation mountain areas, such as in Oman.

| [[#Buerkert--2020|Buerkert et al. (2020)]]

|-
| * Drought conditions negatively affect mountain grasslands ( ''medium confidence'' ), as reported in cases in Tyrol (Austria), Nepal, Afghanistan, Pakistan and China, which can contribute to a decline in agrobiodiversity.

| Ashraf et al. (2014), [[#Zomer--2014b|Zomer et al. (2014b)]] , [[#Grüneis--2018|Grüneis et al. (2018)]] , [[#Adhikari--2019|Adhikari et al. (2019)]] , [[#Chaudhary--2020|Chaudhary et al. (2020)]] , [[#Hussain--2020|Hussain and Qamar (2020)]]

|-
| * In some cases, climate-related hazards lead to outmigration in mountain areas, with indirect negative impacts on labour deficits to support agricultural practices and productivity in mountain areas ( ''medium confidence'' ) (e.g., in Ghana, Tanzania, Thailand and HKH).

| [[#Warner--2014|Warner and Afifi (2014)]] , [[#Wester--2019|Wester et al. (2019)]]

|-
| * Positive impacts (favourable growing conditions) are reported for the production of some fruits and vegetables in the Gilgit-Baltistan province of Pakistan and for the production of traditional crops (e.g., local beans) in the Karnali region of Nepal.

| [[#Hussain--2016b|Hussain et al. (2016b)]] , Thapa and Hussain (2020)

|-
| * Impacts on pastoralism include changes in growing conditions associated with warming temperatures and declining precipitation, which in turn lead to negative impacts on livestock productivity, food security and livelihoods of pastoralist communities, including drought-induced degradation of rangelands ( ''medium confidence'' ) (e.g., in mountainous areas of Mongolia, Tanzania, Nepal and Ethiopia), which exacerbate impoverished conditions in pastoral communities.

| Batima et al. (2013), [[#Rasul--2014|Rasul et al. (2014)]] , [[#Gentle--2016|Gentle and Thwaites (2016)]] , Kimaro et al. (2018), Mekuyie et al. (2018), [[#Tiwari--2020|Tiwari et al. (2020)]]

|-
| rowspan="3"| Responses and adaptations

| * Recharging groundwater and adopting rainwater harvesting (including appropriate tillage methods to improve soil moisture), restoration and rehabilitation of land, diversification of agricultural crops (including introduction of stress resistant crop varieties), promotion of in situ (protected areas, conservation areas) and ex situ (nurseries, gene banks, home gardens) conservation strategies, afforestation and agroforestry.

| Sections 4.7.1.1 and 5.6.3, Cross-Chapter Box FEASIB in Chapter 18

|-
| * Local knowledge is used to help maintain the productive and cultural value of mountain agriculture and pastoralism, such as in the French and Italian Alps, Western Himalaya in India and the mountains of northern Morocco.

| [[#Fassio--2014|Fassio et al. (2014)]] , [[#Kmoch--2018|Kmoch et al. (2018)]] , [[#Das--2021|Das (2021)]]

|-
| * Ecosystem- and community-based adaptations contribute to supporting the diversity and complementarily of management options, permaculture and local capacities to adapt and support ecosystem functions vital for agrobiodiversity ( ''medium confidence'' ).

| [[#Reid--2016|Reid (2016)]] , [[#Grêt-Regamey--2020|Grêt-Regamey and Weibel (2020)]] , Cross-Chapter Box NATURAL in Chapter 2

|-
| colspan="3"| ''Tourism and recreation''

|-
| rowspan="3"| Impacts

| * Since SROCC, the literature on climate change impacts on winter skiing tourism has remained dominated by studies focused on future climate change impacts and projected risks due to decreasing seasonal snow reliability (CCP5.3.1), most relevant when considering snow management and, in particular, snow-making.

| [[#Hock--2019|Hock et al. (2019)]] , [[#Sauri--2020|Sauri and Llurdés (2020)]] , AR6 WG1 Sections 9.5.3 and 12.4.10.4

|-
| * Climate-induced hazards in mountains, such as rockfalls, negatively affect access to some climbing, mountaineering and hiking routes in summer ( ''medium confidence'' ), with cases mainly reported in the European Alps.

| [[#Hock--2019|Hock et al. (2019)]] , Mourey et al. (2019, 2020)

|-
| * Higher temperatures and extreme heat conditions at lower elevations have made some mountain destinations more appealing for human comfort, increasing the potential summer visitation demand and opportunities for tourism and recreation in mountains, such as in the European Alps and the Catalan Pyrenees ( ''medium confidence'' ). However, there is ''limited evidence'' on similar trends in mountain regions outside of Europe.

| [[#Serquet--2011|Serquet and Rebetez (2011)]] , March et al. (2014), [[#Pröbstl-Haider--2015|Pröbstl-Haider et al. (2015)]] , Steiger et al. (2016), Juschten et al. (2019a, b)

|-
| rowspan="6"| Responses and adaptation

| * Diversification of tourism activities to non-snow activities has been reported as an adaptation approach to maintaining economic viability in some winter ski areas, partly due to the high cost of running snow-making infrastructure in winter, for example in the Pyrenees (Europe) and Australian Alps.

| [[#Morrison--2013|Morrison and Pickering (2013)]] , [[#Sauri--2020|Sauri and Llurdés (2020)]]

|-
| * In some cases, managing water resource availability and demand for snow-making is reported, with destination and large-scale governance highlighted as critical aspects for managing trade-offs, including overcoming conflicts arising from competing demands for environmental resources and land use (e.g., in French Alps and in Scandinavia).

| [[#Demiroglu--2019|Demiroglu et al. (2019)]] , [[#Gerbaux--2020|Gerbaux et al. (2020)]]

|-
| * For snow management, examples exist of dedicated climate services designed to enable better-informed decision- making on appropriate long-term adaptation (e.g., through a dedicated Copernicus Climate Change Service or real-time early warning systems).

| [[#Köberl--2021|Köberl et al. (2021)]] , [[#Morin--2021|Morin et al. (2021)]]

|-
| * Barriers to adaptation strategies such as snow-making, for instance in Switzerland, have been linked to perceived economic constraints on their implementation, as well as the social acceptability of these measures.

| [[#Matasci--2014|Matasci et al. (2014)]] , [[#Moser--2020|Moser and Baulcomb (2020)]]

|-
| * Adaptation options to limit exposure to hazards in hiking, climbing or mountaineering activities include shifting the seasonal timing for these activities or changing routes entirely.

| [[#Hock--2019|Hock et al. (2019)]] , Mourey et al. (2019, 2020)

|-
| * In some cases, such as in Bolivia, Peru and New Zealand, and more recently reported in the French Alps, ‘last chance’ tourism has increased the appeal of some mountain destinations, resulting in visitation demand to witness the effects of climate change on iconic mountain landscape features such as glaciers.

| [[#Hock--2019|Hock et al. (2019)]] ; [[#Salim--2020|Salim and Ravanel (2020)]]

|}

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<span id="ccp5.2.6-natural-hazards-and-disasters"></span>
=== CCP5.2.6 Natural Hazards and Disasters ===

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Climate- and weather-related disasters in mountain regions have increased over the last three decades ( ''medium confidence'' ). Disaster frequency shows increasing trends in the HKH, the Andes and mountain regions in Africa, whereas no clear trends are observed for the European Alps and Central Asia ( ''medium confidence'' ) ( [[#Froude--2018|Froude and Petley, 2018]] ; [[#Stäubli--2018|Stäubli et al., 2018]] ).

Floods, debris flows, landslides and avalanches are the most frequent hazards affecting the highest number of people in mountain regions ( ''medium confidence'' ) ( [[#Stäubli--2018|Stäubli et al., 2018]] ). Landslides count among the deadliest hazards globally, with over 150,000 reported fatalities for the period 1995–2014 ( [[#Haque--2019|Haque et al., 2019]] ). There is ''high confidence'' that the number of fatalities from landslides has increased globally over the past 20 years ( [[#Froude--2018|Froude and Petley, 2018]] ; [[#Haque--2019|Haque et al., 2019]] ), but there is ''limited evidence'' that this is due to changes in landslide event frequency and/or magnitude. Infrastructure expansion on unstable terrain can increase disaster risk ( [[#Zimmermann--2015|Zimmermann and Keiler, 2015]] ; [[#Huggel--2019|Huggel et al., 2019]] ; [[#Kirschbaum--2019|Kirschbaum et al., 2019]] ; [[#Schauwecker--2019|Schauwecker et al., 2019]] ; [[#Terzi--2019|Terzi et al., 2019]] ; [[#Motschmann--2020a|Motschmann et al., 2020a]] ; [[#Shugar--2021|Shugar et al., 2021]] ). A study from western Nepal concludes that the exposure of people and infrastructure to hazards has been the main cause of disasters (Muñoz-Torrero Manchado et al., 2021). Decreasing numbers of fatalities from disasters resulting from decreasing vulnerabilities have been reported in Europe and North America ( [[IPCC:Wg2:Chapter:Chapter-13#13.2.2.1|Section 13.2.2.1]] ) ( [[#Gariano--2016|Gariano and Guzzetti, 2016]] ; [[#Strouth--2021|Strouth and McDougall, 2021]] ). Evidence from Africa suggests that disasters from climate-induced natural hazards in mountain areas are often due to droughts, pests and changes in rainfall and associated impacts on smallholder farmers’ agricultural livelihoods ( [[#Shikuku--2017|Shikuku et al., 2017]] ).

The characteristics of natural hazards in mountain areas have been widely explored, and evidence suggests that conditions favouring cascading impacts are a common feature ( ''high confidence'' ) ( [[IPCC:Wg2:Chapter:Chapter-8#8.2.1.1|Section 8.2.1.1]] ) ( [[#Zimmermann--2015|Zimmermann and Keiler, 2015]] ; [[#Huggel--2019|Huggel et al., 2019]] ; [[#Kirschbaum--2019|Kirschbaum et al., 2019]] ; [[#Schauwecker--2019|Schauwecker et al., 2019]] ; [[#Terzi--2019|Terzi et al., 2019]] ; [[#Motschmann--2020a|Motschmann et al., 2020a]] ; [[#Shugar--2021|Shugar et al., 2021]] ). Compound and cascading impacts have affected people, ecosystems and infrastructure and generate significant spillovers across numerous sectors, resulting in destructive impacts ( [[#Nones--2016|Nones and Pescaroli, 2016]] ; [[#Kirschbaum--2019|Kirschbaum et al., 2019]] ; [[#Schauwecker--2019|Schauwecker et al., 2019]] ).

Most adaptation responses to natural hazards in mountain regions are reactive to specific climate stimuli or post-disaster recovery ( ''robust evidence, medium agreement'' ) ( [[#McDowell--2019|McDowell et al., 2019]] ; [[#Rasul--2020|Rasul et al., 2020]] ). Hard structural measures such as dikes, dam reservoirs and embankments have been widely employed to contain hazards, along with early warning systems, zonation and land management (Box 4.1, 10.4.4.5, 12.5.3 and 13.2.2). Awareness raising, preparedness and disaster response plans are increasingly used in the context of more unpredictable hazard trends (see Cross-Chapter Box DEEP in Chapter 17) ( [[#Allen--2016|Allen et al., 2016]] , 2018; [[#Hovelsrud--2018|Hovelsrud et al., 2018]] ). Ecosystem-based adaptations (EBAs) are widely implemented to mitigate risks from shallow landslides (e.g., afforestation and reforestation and improved forest management), floods (e.g., river restoration and renaturation) ( [[#Renaud--2016|Renaud et al., 2016]] ; [[#Klein--2019b|Klein et al., 2019b]] ) and droughts (e.g., adapting watershed) ( [[#Renaud--2016|Renaud et al., 2016]] ; [[#Klein--2019b|Klein et al., 2019b]] ; [[#Palomo--2021|Palomo et al., 2021]] ).

Evidence from different mountain regions shows that adaptation and risk reduction efforts are less successful if they focus on hazards or risks without considering diverse risk and value perceptions of the affected people ( ''medium confidence'' ) ( [[#French--2015|French et al., 2015]] ; [[#Allen--2018|Allen et al., 2018]] ; [[#Hovelsrud--2018|Hovelsrud et al., 2018]] ; [[#Kadetz--2018|Kadetz and Mock, 2018]] ; [[#Klein--2019b|Klein et al., 2019b]] ). Previous experience and local social contexts of exposure to climate-related disasters affect people’s perceptions and influence the patterns associated with disaster risk management and associated coping strategies ( ''high confidence'' ) (SROCC [[IPCC:Wg2:Chapter:Chapter-2|Chapter 2]] ( [[#Hock--2019|Hock et al., 2019]] )), ( [[#Kaul--2014|Kaul and Thornton, 2014]] ; [[#Shijin--2015|Shijin and Dahe, 2015]] ; [[#Landeros-Mugica--2016|Landeros-Mugica et al., 2016]] ; [[#Wirz--2016|Wirz et al., 2016]] ; [[#Carey--2017|Carey et al., 2017]] ; [[#Adler--2019|Adler et al., 2019]] ).

Important synergies exist between disaster risk reduction, climate change adaptation and sustainable development in mountain regions ( ''medium confidence'' ) ( [[#Zimmermann--2015|Zimmermann and Keiler, 2015]] ), where the multiple and diverse perceptions of risk and risk tolerance for natural hazards are relevant considerations ( [[#Schneiderbauer--2021|Schneiderbauer et al., 2021]] ). Global agreements for integrated disaster risk management and climate change adaptation ( [[#Alcántara-Ayala--2017|Alcántara-Ayala et al., 2017]] ), including the Sendai Framework for Disaster Risk Reduction 2015–2030 ( [[#UNISDR--2015|UNISDR, 2015]] ), the SDGs ( [[#UN--2015|UN, 2015]] ), the Paris Agreement ( [[#UNFCCC--2015|UNFCCC, 2015]] ) and the New Urban Agenda-Habitat III (UN, 2016), create opportunities for synergies to address disaster risks (see also [[IPCC:Wg2:Chapter:Chapter-6#6.3|Section 6.3]] ). Although these agreements are well established in international agendas, there is ''limited evidence'' of their implementation to address disaster risk reduction and adaptation in mountains ( [[#Alcántara-Ayala--2017|Alcántara-Ayala et al., 2017]] ).

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<span id="ccp5.2.7-synthesis-of-observed-impacts-and-attribution-and-observed-adaptations"></span>
=== CCP5.2.7 Synthesis of Observed Impacts and Attribution and Observed Adaptations ===

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<span id="ccp5.2.7.1-observed-impacts-and-attribution-to-anthropogenic-climate-change"></span>
==== CCP5.2.7.1 Observed Impacts and Attribution to Anthropogenic Climate Change ====

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The assessment of observed impacts identified a large number of impacts across all major mountain regions of the world and for a large variety of systems, based on more than 300 references (SMCCP5.2). The literature was assessed and the results classified on a per-region and per-system basis. Confidence statements on detection and attribution are based on expert judgement following IPCC guidelines ( [[IPCC:Wg2:Chapter:Chapter-1#1.3.4|Section 1.3.4]] ), building on evidence from multiple sources in the literature ( [[#Mach--2017|Mach et al., 2017]] ) (SMCCP5.2). Figure CCP5.4 provides an overview of the assessment results.

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[[File:a73cf4f2f1c552dbb3cb3f07140e64fa IPCC_AR6_WGII_Figure_CCP5_004.png]]

'''Figure CCP5.4 |''' '''Synthesis of detection and attribution of impacts of anthropogenic climate change on different natural and human systems in mountain regions.''' For each system and region assessed, the level of confidence for detection and for attribution to anthropogenic climate change is indicated. Also indicated is how strong the contribution of climate change is to the observed changes, considering climatic and non-climatic causal factors. Observed impacts were analysed in terms of negative impacts (e.g., economic or non-economic damages, losses, contribution to increasing risks for society), where the numbers refer to the percentage of references indicating negative impacts for a given impact. The percentage of local community perception indicates the percentage of all literature references for a given system and region that account for local knowledge. The number of references refers to the total number of literature references considered for an impact on a specific system and region. ‘Not assessed’ refers to ''limited evidence'' in the literature (SMCCP5.2 and Table SMCCP5.5–5.14).

Climate change impacts have been documented in mountains on all continents. A wide range of human and natural systems have been affected by climate change to date, including the cryosphere, water resources, terrestrial and aquatic ecosystems, agriculture, tourism, energy production, infrastructure, health and life, migration, disasters and community and cultural values. The confidence levels for the detection of impacts are generally in the range of medium to high. The contribution of climate change to detected impacts varies depending on the affected system and on climatic and non-climatic drivers. The highest levels of confidence for the attribution of detected impacts to anthropogenic climate change are related to the cryosphere. More generally, those impacts are more strongly driven by increasing temperatures and show higher confidence for attribution than those impacts driven mainly by precipitation changes. The level of contribution of climate change to observed impacts is predominantly medium or high, indicating the high sensitivity of natural and human systems in mountains to climate change. Furthermore, the vast majority of detected impacts imply negative impacts on natural and human systems ( ''high confidence'' ).

Local knowledge plays an important role in documenting impacts of climate change in mountain regions. Since IPCC AR5, the evidence for meaningful climate change impacts being reported using local knowledge sources has increased substantially ( ''high confidence'' ). Similarly, important regional gaps present in the IPCC AR5 are addressed here (e.g., Africa), resulting in a much more comprehensive and regionally balanced assessment and perspective.

Furthermore, the science of attributing negative impacts of climate change to anthropogenic emissions or even individual polluters is becoming increasingly important for climate litigation ( [[#Marjanac--2017|Marjanac et al., 2017]] ; [[#McCormick--2017|McCormick et al., 2017]] ; [[#Otto--2017|Otto et al., 2017]] ; [[#Setzer--2019|Setzer and Vanhala, 2019]] ), and there is emerging evidence that mountains are becoming sites of litigation cases, with cases, for instance, in Peru, Colombia and India ( [[#UNEP--2017|UNEP, 2017]] ). Recent studies put litigation cases such as the Lliuya vs RWE (the German multi-national energy company) case, on the risk of glacier lake floods in Peru, in a broader context of differentiated responsibilities and justice ( [[#Huggel--2020b|Huggel et al., 2020b]] ).

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<span id="ccp5.2.7.2-synthesis-of-observed-adaptation"></span>
==== CCP5.2.7.2 Synthesis of Observed Adaptation ====

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Extending from recent assessments of observed adaptation in high mountain areas ( [[#Hock--2019|Hock et al., 2019]] ; [[#McDowell--2019|McDowell et al., 2019]] ) new evidence for the geographically larger space for mountains assessed in this CCP is available from a mountain-specific reanalysis of the GAMI data set, which contains 423 articles reporting adaptation in mountains ( [[#Berrang-Ford--2021|Berrang-Ford et al., 2021]] ; [[#McDowell--2021b|McDowell et al., 2021b]] ) (SMCCP5.3), some of which also include those reported in Section CCP5.2. In these articles, adaptation measures in mountains are reported from all regions worldwide, with a preponderance from Asia and Africa. Of all reported adaptations, 91% involve individuals or households, frequently engaged in smallholder agriculture and/or pastoralism; local governments are also often involved (31%), as are sub-national or local civil society actors (29%), while private-sector involvement remains scarce (below 10%). Food, fibre and other ecosystem products (76%) and poverty, livelihoods and sustainable development (55%) are by far the most often reported adaptations in mountains, followed by water and sanitation (28%) and health, well-being and communities (26%) ( [[#McDowell--2021b|McDowell et al., 2021b]] ) (SMCCP5.3.2).

Adaptation measures most commonly found include farming-related changes (e.g., resilient or drought-tolerant crop varieties, irrigation techniques, crop storage and livestock insurance schemes), infrastructure development, Indigenous knowledge, community-based capacity-building and ecosystem-based adaptation ( ''high confidence'' ) ( [[#McDowell--2021b|McDowell et al., 2021b]] ) (SMCCP5.3.2). Nature-based solutions (NbS) are an adaptation component in the nationally determined contributions (NDCs) of many mountain countries around the world ( [[#UNEP--2021|UNEP, 2021]] ). Furthermore, Indigenous knowledge and local knowledge are often reported as informing adaptation efforts, and Indigenous Peoples, marginalised people and gender issues are recognised in several national adaptation strategies, but autonomous responses are often insufficiently understood ( [[#Mishra--2019|Mishra et al., 2019]] ).

The GAMI-based reanalysis for mountains indicates that food security (75%), poverty (47%), consumption and production (36%), terrestrial and freshwater ecosystem services (19%) and clean water and sanitation (18%) are important aspects of vulnerability that adaptations address, with an emphasis on responses to climate-related shocks and stressors ( [[#McDowell--2021b|McDowell et al., 2021b]] ) (SMCCP5.2). The reanalysis also shows that more than 80% of adaptations in mountains are behavioural/cultural in nature, and more than 50% are ecosystem-based or technological or infrastructural.

About a third of the assessed adaptation activities are in the planning and early implementation stage, and around a fifth are in a stage of advanced implementation ( [[#McDowell--2021b|McDowell et al., 2021b]] ) (SMCCP5.3.2). Several lines of evidence converge, indicating that most observed adaptations in mountains are incremental in nature and not transformative ( ''high confidence'' ) ( [[#Mishra--2019|Mishra et al., 2019]] ; [[#McDowell--2021b|McDowell et al., 2021b]] ) (SMCCP5.3.2). Nevertheless, some adaptation measures such as NbS were found to have important transformative potential in mountains if different knowledge types are combined, and community engagement and ecosystem management processes are in place ( [[#Palomo--2021|Palomo et al., 2021]] ).

Overall, and consistent with the findings in SROCC, the systematic monitoring and evaluation processes that have been implemented to track adaptation progress remain limited, and there is ''limited evidence'' and prevailing uncertainties on the extent to which observed adaptation efforts reduce risks ( [[#Hock--2019|Hock et al., 2019]] ; [[#McDowell--2021b|McDowell et al., 2021b]] ; [[#UNEP--2021|UNEP, 2021]] ) (SMCCP5.3.2).

Limits to adaptation are found in a majority (&gt;80%) of the assessed adaptation studies; around half of the studies reported soft limits, and less than a third identified both hard and soft limits to adaptation ( ''high confidence'' ) ( [[#McDowell--2021b|McDowell et al., 2021b]] ) (SMCCP5.3.2). Soft limits are frequently related to governance, economics and social/cultural constraints and can be overcome in principle through targeted efforts to address social conditions that impede adaptation planning and action. Hard limits are more frequently described as biophysical, such as precipitous declines in water supply. Examples of adaptation limits include lack of access to credit and markets, fixed livelihoods, insufficient awareness of climate risk, poor access to technology, the erosion of existing skills and knowledge, social inequities, lack of trust and social cohesion, inequitable gender norms and perceptions of conflict or scarcity. Furthermore, land tenure insecurity, poor integration of adaptation programmes across governing scales and a lack of decision-making power among vulnerable groups, along with inadequate funding for government-implemented adaptation programmes, are reported to limit adaptation ( [[#Mishra--2019|Mishra et al., 2019]] ; [[#McDowell--2021b|McDowell et al., 2021b]] ) (SMCCP5.3.2). Hard limits imply that further adaptation action is unfeasible, ineffective or unacceptable, resulting in inevitable losses and damages in mountain areas ( ''medium evidence, medium agreement'' ) ( [[#Huggel--2019|Huggel et al., 2019]] ).

Overall, adaptation in mountain regions is taking place in various ways, in different sectors, scales, levels, quality, and effectiveness ( ''high confidence'' ). Most responses are incremental, with asymmetries of power among state, institutions and individuals, costs or capital requirements of adaptation, lack of coordinated planning, resistance to institutional change, household risk aversion, and lack of access to information inhibiting more transformational responses (SMCCP5.3.2). Aside from poverty reduction, there is ''limited evidence'' of adaptations effectively remediating the underlying social determinants of vulnerability (e.g., gender, ethnic identity).

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