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

===== Observed changes, their impacts and adaptation responses in mountains =====

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'''Climate change impacts in mountains and their attribution to human influence have increased in recent decades with observable and serious consequences for people and ecosystems in many mountain regions (''' '''''high confidence''''' [[#footnote-001|1]] ''').''' Observed changes include increasing temperatures, changing seasonal weather patterns, reductions in snow cover extent and duration at low elevation, loss of glacier mass, increased permafrost thaw and an increase in the number and size of glacier lakes ( ''high confidence'' ). {CCP5.2.7, Figure CCP5.4, SROCC Chapter 2, WGI Section 9.5}

'''The spatial distributions of many plant species have shifted to higher elevations in recent decades, consistent with rising temperatures across most mountain regions (''' '''''high confidence''''' ''').''' Around two-thirds of treeline ecotones have also shifted upwards in recent decades, though these shifts are not ubiquitous and slower than expected based on rising temperatures ( ''high confidence'' ). Impacts on biological communities and animal species are also increasingly being reported, with species of lower elevations increasing in mountain regions, creating more homogeneous vegetation and increasing risks to mountain-top species ( ''medium confidence'' ). {CCP5.2.1; 2.4}

'''Climate and cryosphere change have negatively impacted the water cycle in mountains, including variable timing of glacier melt and snowmelt stream discharge (''' '''''high confidence''''' '''). These changes have variable impacts on water availability for people and economies, contributing to increasing tensions or conflicts over water resources, especially in seasonally dry regions (''' '''''medium confidence''''' ''').''' Mountains are an essential source of freshwater for large and growing populations; the number of people largely or fully dependent on water from mountains has increased worldwide from approximately 0.6 billion in the 1960s to approximately 2 billion in the past decade, and globally two-thirds of irrigated agriculture depends on essential runoff contributions from mountains. {CCP5.2.2; Figure CCP5.2; SROCC Chapter 2; 4.2.2.3; 4.4.4.1}

'''Climate-change-driven changes in precipitation, river flow regimes and landslides affect the production and use of energy in mountain regions, in particular hydropower (''' '''''high confidence''''' ''').''' Billions of USD in investment and assets of energy production are exposed to changing mountain hazards. The combined effects of climate change, hydropower development and other human interventions have exacerbated water security problems and social injustice ( ''medium confidence'' ). {CCP5.2.2, SROCC Chapter 2}

'''Observed climate-driven impacts on mountain ecosystem services, agriculture and pastoralism are largely negative in most mountain regions (''' '''''medium confidence''''' ''').''' Agriculture has been negatively affected through increased exposure to hazards such as droughts and floods, changes in the onset of seasons, the timing and availability of water, increasing pests and decreasing pollinator diversity, which in turn have negatively influenced overall food production, dietary diversity and the nutritional value of food ( ''medium confidence'' ). Negative climate impacts on pastoralism, such as drought-induced degradation of rangelands and pastures, have affected livestock productivity and the livelihood of pastoralists, while other non-climatic factors, such as land use change and management, also play a role ( ''medium confidence'' ). {CCP5.2.3; CCP5.2.5; Table CCP5.2; SROCC Section 2.3.1.3.2; SROCC Section 2.3.7}

'''While contributing to poverty reduction in some mountain regions, there is''' '''''limited evidence''''' '''of adaptations effectively contributing to the remediation of underlying social determinants of vulnerability, such as gender and ethnicity (''' '''''medium confidence''''' ''').''' Exposure and vulnerability exacerbate the negative effects of climate impacts on livelihoods and intertwine with power imbalances and gender and other inequalities ( ''medium confidence'' ). {CCP5.2.7; CCP5.3.2.2 }

'''Observed changes in seasonality (timing and extent) are negatively affecting mountain winter tourism and recrea''' '''t''' '''ion (''' '''''high confidence''''' ''') and variably affect tourism and recreation activities in other seasons (''' '''''medium confidence''''' ''').''' For winter activities such as skiing, diminishing snow at lower elevations has challenged operating conditions ( ''medium confidence'' ), increasing the demand for and dependence on snow management measures such as snow-making ( ''high confidence'' ). Climate-induced hazards are negatively affecting some climbing, mountaineering and hiking routes ( ''medium confidence'' ). In some regions, options to change routes or shift seasons to reduce hazard exposure have been employed as adaptation strategies, with variable outcomes ( ''medium confidence).'' In some cases, higher temperatures and extreme heat conditions at lower elevations have made some mountain destinations more appealing, increasing the potential for summer visitation demand ( ''medium confidence'' ). {CCP5.2.5; Table CCP5.2; SROCC Section 2.3.5}

'''Climate-related hazards, such as flash floods and landslides, have contributed to an increase in disasters affecting a growing number of people in mountain regions and areas further downstream (''' '''''high confidence''''' ''').''' As a result, the number of disasters has increased; however, there is ''limited evidence'' that this is due to changes in the underlying hazard processes, pointing mainly to increasing levels of exposure ( ''medium confidence'' ). {CCP5.2.6; CCP5.2.7; CCP5.3.2.1 } .

'''Adaptation responses to climate-driven impacts in mountain regions vary significantly in terms of goals and priorities, scope, depth and speed of implementation, governance and modes of decision-making and the extent of financial and other resources to implement them (''' '''''high confidence''''' ''').''' Observed adaptation responses in mountains are largely incremental and mainly focus on early warning systems and the diversification of livelihood strategies in smallholder agriculture, pastoralism and tourism. However, there is ''limited evidence'' of the feasibility and long-term effectiveness of these measures in addressing climate-related impacts and related losses and damages, including in cities and settlements experiencing changing demographics. {CCP5.2.4; CCP5.2.7.2 }

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