Editing IPCC:AR6/SROCC/SPM (section)

==== Projected Risks for People and Ecosystem Services ====

'''B.7. Future cryosphere changes on land are projected to affect water resources and their uses, such as hydropower ( ''high confidence'' ) and irrigated agriculture in and downstream of high mountain areas ( ''medium confidence'' ), as well as livelihoods in the Arctic ( ''medium confidence'' ). Changes in floods, avalanches, landslides, and ground destabilization are projected to increase risk for infrastructure, cultural, tourism, and recreational assets ( ''medium confidence'' ). {2.3, 2.3.1, 3.4.3}'''

'''B.7.1''' [[File:7dd9d5f1c0e829eec2bf341c5154813e SPM-Icon-xxoo.png]] Disaster risks to human settlements and livelihood options in high mountain areas and the Arctic are expected to increase ( ''medium confidence'' ), due to future changes in hazards such as floods, fires, landslides, avalanches, unreliable ice and snow conditions, and increased exposure of people and infrastructure ( ''high confidence'' ). Current engineered risk reduction approaches are projected to be less effective as hazards change in character ( ''medium confidence'' ). Significant risk reduction and adaptation strategies help avoid increased impacts from mountain flood and landslide hazards as exposure and vulnerability are increasing in many mountain regions during this century ( ''high confidence'' ). {2.3.2, 3.4.3, 3.5.2}

'''B.7.2''' [[File:7dd9d5f1c0e829eec2bf341c5154813e SPM-Icon-xxoo.png]] Permafrost thaw-induced subsidence of the land surface is projected to impact overlying urban and rural communication and transportation infrastructure in the Arctic and in high mountain areas ( ''medium confidence'' ). The majority of Arctic infrastructure is located in regions where permafrost thaw is projected to intensify by mid-century. Retrofitting and redesigning infrastructure has the potential to halve the costs arising from permafrost thaw and related climate-change impacts by 2100 ( ''medium confidence'' ). {2.3.4, 3.4.1, 3.4.3}

'''B.7.3''' [[File:4d299f9da92412c8279a7422468e6e12 SPM-Icon-xooo.png]] High mountain tourism, recreation and cultural assets are projected to be negatively affected by future cryospheric changes ( ''high confidence'' ). Current snowmaking technologies are projected to be less effective in reducing risks to ski tourism in a warmer climate in most parts of Europe, North America, and Japan, in particular at 2°C global warming and beyond ( ''high confidence'' ). {2.3.5, 2.3.6}

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'''B.8. Future shifts in fish distribution and decreases in their abundance and fisheries catch potential due to climate change are projected to affect income, livelihoods, and food security of marine resource-dependent communities ( ''medium confidence'' ). Long-term loss and degradation of marine ecosystems compromises the ocean’s role in cultural, recreational, and intrinsic values important for human identity and well-being ( ''medium confidence'' ). {3.2.4, 3.4.3, 5.4.1, 5.4.2, 6.4} '''

'''B.8.1''' [[File:37d9ca019c63e0a7a080aaca0b2016e4 SPM-Icon-oxox.png]] Projected geographical shifts and decreases of global marine animal biomass and fish catch potential are more pronounced under RCP8.5 relative to RCP2.6 elevating the risk for income and livelihoods of dependent human communities, particularly in areas that are economically vulnerable ( ''medium confidence'' ). The projected redistribution of resources and abundance increases the risk of conflicts among fisheries, authorities or communities ( ''medium confidence'' ). Challenges to fisheries governance are widespread under RCP8.5 with regional hotspots such as the Arctic and tropical Pacific Ocean ( ''medium confidence'' ). {3.5.2, 5.4.1, 5.4.2, 5.5.2, 5.5.3, 6.4.2, Figure SPM.3}

'''B.8.2''' [[File:22af16650531e42ab6972bf52565981a SPM-Icon-oxxx.png]] The decline in warm-water coral reefs is projected to greatly compromise the services they provide to society, such as food provision ( ''high confidence'' ), coastal protection ( ''high confidence'' ) and tourism ( ''medium confidence'' ). Increases in the risks for seafood security ( ''medium confidence'' ) associated with decreases in seafood availability are projected to elevate the risk to nutritional health in some communities highly dependent on seafood ( ''medium confidence'' ), such as those in the Arctic, West Africa, and Small Island Developing States. Such impacts compound any risks from other shifts in diets and food systems caused by social and economic changes and climate change over land ( ''medium confidence'' ). {3.4.3, 5.4.2, 6.4.2}

'''B.8.3''' [[File:22af16650531e42ab6972bf52565981a SPM-Icon-oxxx.png]] Global warming compromises seafood safety ( ''medium confidence'' ) through human exposure to elevated bioaccumulation of persistent organic pollutants and mercury in marine plants and animals ( ''medium confidence'' ), increasing prevalence of waterborne ''Vibrio'' pathogens ( ''medium confidence'' ), and heightened likelihood of harmful algal blooms ( ''medium confidence'' ). These risks are projected to be particularly large for human communities with high consumption of seafood, including coastal Indigenous communities ( ''medium confidence'' ), and for economic sectors such as fisheries, aquaculture, and tourism ( ''high confidence'' ). {3.4.3, 5.4.2, Box 5.3}

'''B.8.4''' [[File:22af16650531e42ab6972bf52565981a SPM-Icon-oxxx.png]] Climate change impacts on marine ecosystems and their services put key cultural dimensions of lives and livelihoods at risk ( ''medium confidence'' ), including through shifts in the distribution or abundance of harvested species and diminished access to fishing or hunting areas. This includes potentially rapid and irreversible loss of culture and local knowledge and Indigenous knowledge, and negative impacts on traditional diets and food security, aesthetic aspects, and marine recreational activities ( ''medium confidence'' ). {3.4.3, 3.5.3, 5.4.2}

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'''B.9. Increased mean and extreme sea level, alongside ocean warming and acidification, are projected to exacerbate risks for human communities in low-lying coastal areas ( ''high confidence'' ). In Arctic human communities without rapid land uplift, and in urban atoll islands, risks are projected to be moderate to high even under a low emissions scenario (RCP2.6) ( ''medium confidence'' ), including reaching adaptation limits ( ''high confidence'' ). Under a high emissions scenario (RCP8.5), delta regions and resource rich coastal cities are projected to experience moderate to high risk levels after 2050 under current adaptation ( ''medium confidence'' ). Ambitious adaptation including transformative governance is expected to reduce risk ( ''high confidence'' ), but with context-specific benefits. {4.3.3, 4.3.4, SM4.3, 6.9.2, Cross-chapter Box 9, Figure SPM.5}'''

'''B.9.1''' [[File:3dcc514bf2acf9f1b7861bf877ef79a9 SPM-Icon-ooxo.png]] In the absence of more ambitious adaptation efforts compared to today , and under current trends of increasing exposure and vulnerability of coastal communities, risks, such as erosion and land loss, flooding, salinization, and cascading impacts due to mean sea level rise and extreme events are projected to significantly increase throughout this century under all greenhouse gas emissions scenarios ( ''very high confidence'' ). Under the same assumptions, annual coastal flood damages are projected to increase by 2–3 orders of magnitude by 2100 compared to today ( ''high confidence'' ). {4.3.3, 4.3.4, Box 6.1, 6.8, SM4.3, Figures SPM.4, SPM.5}

'''B.9.2''' [[File:22af16650531e42ab6972bf52565981a SPM-Icon-oxxx.png]] High to very high risks are approached for vulnerable communities in coral reef environments, urban atoll islands and low-lying Arctic locations from sea level rise well before the end of this century in case of high emissions scenarios. This entails adaptation limits being reached, which are the points at which an actor’s objectives (or system needs) cannot be secured from intolerable risks through adaptive actions ( ''high confidence'' ). Reaching adaptation limits (e.g., biophysical, geographical, financial, technical, social, political, and institutional) depends on the emissions scenario and context-specific risk tolerance, and is projected to expand to more areas beyond 2100, due to the long-term commitment of sea level rise ( ''medium confidence'' ). Some island nations are ''likely'' to become uninhabitable due to climate-related ocean and cryosphere change ( ''medium confidence'' ), but habitability thresholds remain extremely difficult to assess. {4.3.4, 4.4.2, 4.4.3, 5.5.2, Cross-Chapter Box 9, SM4.3, SPM C.1, Glossary, Figure SPM.5}

'''B.9.3''' [[File:f83f15a29ea2d8a2d2ddc3ce832f4aaa SPM-Icon-oxxo.png]] Globally, a slower rate of climate-related ocean and cryosphere change provides greater adaptation opportunities ( ''high confidence'' ). While there is ''high confidence'' that ambitious adaptation, including governance for transformative change, has the potential to reduce risks in many locations, such benefits can vary between locations. At global scale, coastal protection can reduce flood risk by 2–3 orders of magnitude during the 21st century, but depends on investments on the order of tens to several hundreds of billions of US$ per year ( ''high confidence'' ). While such investments are generally cost efficient for densely populated urban areas, rural and poorer areas may be challenged to afford such investments with relative annual costs for some small island states amounting to several percent of GDP ( ''high confidence'' ). Even with m ajor adaptation efforts, residual risks and associated losses are projected to occur ( ''medium confidence'' ), but context-specific limits to adaptation and residual risks remain difficult to assess. {4.1.3, 4.2.2.4, 4.3.1, 4.3.2, 4.3.4, 4.4.3, 6.9.1, 6.9.2, Cross-Chapter Boxes 1–2 in Chapter 1, SM4.3, Figure SPM.5}

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'''Figure SPM.4'''

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'''Figure SPM.4 | The effect of regional sea level rise on extreme sea level events at coastal locations. (a) Schematic illustration of extreme sea level events and their average recurrence in the recent past (1986–2005) and the future. As a consequence of mean sea level rise, local sea levels that historically occurred once per century […]'''
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[[File:7de20b07a73c6b860a4cf35d205de36e SROCC_SPM4_Final_edit_AA-3000x2852.jpg]]

Figure SPM.4 | The effect of regional sea level rise on extreme sea level events at coastal locations. (a) Schematic illustration of extreme sea level events and their average recurrence in the recent past (1986–2005) and the future. As a consequence of mean sea level rise, local sea levels that historically occurred once per century (historical centennial events, HCEs) are projected to recur more frequently in the future. (b) The year in which HCEs are expected to recur once per year on average under RCP8.5 and RCP2.6, at the 439 individual coastal locations where the observational record is sufficient. The absence of a circle indicates an inability to perform an assessment due to a lack of data but does not indicate absence of exposure and risk. The darker the circle, the earlier this transition is expected. The likely range is ±10 years for locations where this transition is expected before 2100. White circles (33% of locations under RCP2.6 and 10% under RCP8.5) indicate that HCEs are not expected to recur once per year before 2100. (c) An indication at which locations this transition of HCEs to annual events is projected to occur more than 10 years later under RCP2.6 compared to RCP8.5. As the scenarios lead to small differences by 2050 in many locations results are not shown here for RCP4.5 but they are available in Chapter 4. {4.2.3, Figure 4.10, Figure 4.12}

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