Editing IPCC:AR6/SROCC/Chapter-5 (section)

== Box 5.4 Harmful Algal Blooms and Climate Change ==

<div id="section-5-4-2-1human-health-and-environmental-health-block-1"></div>

Harmful Algal Blooms (HABs) are proliferations of phytoplankton (mostly dinoflagellates, diatoms and cyanobacteria) and macroaglae that have negative effects on marine environments and associated biota. Impacts include water discolouration and foam accumulation, anoxia, contamination of seafood with toxins, disruption of food webs and massive large-scale mortality of marine biota (Hallegraeff, 2010; Quillien et al., 2015; Amaya et al., 2018; García-Mendoza et al., 2018; Álvarez et al., 2019). The IPCC 5th Assessment Report (AR5) concluded that harmful algal outbreaks had increased in frequency and intensity, caused partly by warming, nutrient fluctuations in upwelling areas, and coastal eutrophication ( ''medium confidence'' ); however, there was ''limited evidence'' and ''low confidence'' for future climate change effects on HABs (AR5 Chapters 5, 6) (Pörtner et al., 2014; Wong et al., 2014b). Since AR5, HABs have increasingly affected human society, with negative impacts on food provisioning, tourism, the economy and human health (Anderson et al., 2015; Berdalet et al., 2017). For example, HABs caused an estimated loss of 42 million USD for the tuna industry in Baja California, Mexico (García-Mendoza et al., 2018) and mortality of more than 40,000 tonnes of cultivated salmon in Chile (Díaz et al., 2019). This additional observational and experimental evidence has improved detection and attribution of HABs to climate change, demonstrating that shifts in biogeography, increased abundance and increased toxicity of HABs in recent years have been partly or wholly caused by warming and by other, more direct human drivers.

New studies since AR5 show range expansion of warm water HAB species, such as ''Gambierdiscus'' that causes ciguatera fish poisoning (Kohli et al., 2014; Bravo et al., 2015; Sparrow et al., 2017); contraction of cold water species (Tester et al., 2010; Rodríguez et al., 2017); the detection of novel phycotoxins and toxic species (Akselman et al., 2015; Guinder et al., 2018; Paredes et al., 2019; Tillmann et al., 2019); and regional increases in the occurrence and intensity of toxic phytoplankton blooms (McKibben et al., 2017; Díaz et al., 2019) in relation to ocean warming. For example, growth of the toxic dinoflagellates ''Alexandrium'' and ''Dinophysis,'' producers of paralytic shellfish poisoning and okadaic acid, respectively, is enhanced by warmer conditions in the North Atlantic and North Pacific (Gobler et al., 2017), whilst environmental conditions linked with warm phases of El Niño Southern Oscillation ENSO are associated with blooms of toxic ''Pseudo-nitzschia'' species in the Northern California Current (McKibben et al., 2017), with devastating effects on coastal ecosystems (McCabe et al., 2016; Ritzman et al., 2018). Regional variations of trends in HAB occurrences can be explained by spatial differences in climate drivers (temperature, water column stratification, ocean acidification, precipitation and extreme weather events), as well as non-climatic drivers, such as eutrophication and pollution (Hallegraeff, 2010; Hallegraeff, 2016; Glibert et al., 2018; Paerl et al., 2018).

Experimental studies have provided additional evidence for the role of environmental drivers in inducing HABs and their degree of impact. These studies include those showing that toxin production can be affected by grazers (Tammilehto et al., 2015; Xu and Kiørboe, 2018) and changing nutrient levels (Van de Waal et al., 2013; Brunson et al., 2018). The biosynthesis of domoic acid by some ''Pseudo-nitschia'' species is induced by combined phosphate limitation and high CO 2 conditions (Brunson et al., 2018), with their growth and toxicity enhanced by warming in incubation experiments (Zhu et al., 2017). Recent mesocosm experiments using natural subtropical planktonic communities found that simulated CO 2 emission scenarios (between Representative Concentration Pathway (RCP)2.6 and RCP8.5 by 2100) improved the competitive fitness of the toxic microalgae ''Vicicitus globosus'' for CO 2 treatments above 600 μatm, and induced blooms above 800 μatm, with severe negative impacts for other components of the planktonic food web (Riebesell et al., 2018). Experiments with the toxic dinoflagellate ''Akashiwo sanguinea'' (hemolytic activity) have also shown that a combination of high CO 2 levels, warming and high irradiance stimulate the growth and toxicity of this HAB species (Ou et al., 2017).

Given the worldwide distribution of the key toxic species of ''Alexandrium'' , ''Pseudo-nitzschia'' and ''Dinophysis'' , if the current relationship between warming and the occurrences of HABs associated with these species persists in the future (Gobler et al., 2017; Townhill et al., 2018) ( ''medium confidence'' ), the projected changes in ocean conditions can be expected to intensify HAB-related risks for coastal biodiversity and ecosystems services ( ''high confidence'' ) ''.'' The greatest risk is expected for estuarine organisms (Section 5.3.1) because HABs occurrences are stimulated by riverine nutrient loads, and exacerbated by warming and the lower dissolved oxygen and pH in estuarine environments (Gobler and Baumann, 2016; Paredes-Banda et al., 2018).

Local scale sustained monitoring programmes and early warning systems for HABs can alert resource managers and stakeholders of their potential occurrences so that they can take actions (e.g., toxic seafood alerts or relocation of activities) to reduce the impacts of HABs (Anderson et al., 2015; Wells et al., 2015) ( ''high confidence'' ). There is ''limited evidence'' in determining the degree to which reduction of non-climatic anthropogenic stressors can reduce risk of HABs (Section 5.5.2), although this approach may be effective in some areas ( ''low confidence'' ); for example, controlling nutrient inputs from human sources may reduce the risk of occurrence of HABs in the Baltic Sea. Other techniques such as active chemical and biological interventions are at experimental stage.

Overall, the occurrence of HABs, their toxicity and risk on natural and human systems are projected to continue to increase with warming and rising CO 2 in the 21st century(Glibert et al., 2014; Martín-García et al., 2014; McCabe et al., 2016; Paerl et al., 2016; Gobler et al., 2017; McKibben et al., 2017; Rodríguez et al., 2017; Paerl et al., 2018; Riebesell et al., 2018) ( ''high confidence).'' Moreover, poleward distributional shifts of HAB species are expected to continue as a result of warming (Townhill et al., 2018) ''.'' The increasing likelihood of occurrences of HABs under climate change also elevates their risks on ecosystem services such as fisheries, aquaculture and tourism as well as public health (Section 5.4.2, ''high confidence'' ). Such risks will be greatest in poorly monitored areas (Borbor-Córdova et al., 2018; Cuellar-Martinez et al., 2018)

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<span id="interactions-between-climate-change-and-contaminants"></span>
===== 5.4.2.1.2 Interactions between climate change and contaminants =====

Climate change–contaminant interactions can alter the bioaccumulation and amplify biomagnification of several contaminant classes (Boxall et al., 2009; Alava et al., 2018). This section assesses two types of contaminants that are of concern to environmental and human health as examples of other contaminants with similar properties (Alava et al., 2017). These two types of contaminants are the toxic and fat-soluble persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), as well as the neurotoxic and protein-binding organic form of mercury, methylmercury (MeHg) (Alava et al., 2017). POPs and MeHg are bioaccumulated by marine organisms and biomagnified in food webs, reaching exposure concentrations that become harmful and toxic to populations of apex predators such as marine mammals (Desforges et al., 2017; Desforges et al., 2018) (Figure 5.20). Human exposure to POPs and MeHg can lead to serious health effects (Ishikawa and Ikegaki, 1980; UNEP, 2013; Fort et al., 2015; Scheuhammer et al., 2015).

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'''Figure 5.20'''

<span id="figure-5.20-the-pathways-through-which-scenario-of-climatic-and-pollutant-hazards-orange-boxes-and-their-interactions-can-lead-to-increases-in-exposure-to-hazards-by-the-biota-ecosystems-and-people-their-sensitivity-blue-box-and-the-risk-of-impacts-to-ecosystem-and-human-health-and-societies-red-box.-such-risks-will-interact-with"></span>
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'''Figure 5.20 | The pathways through which scenario of climatic and pollutant hazards (orange boxes) and their interactions can lead to increases in exposure to hazards by the biota, ecosystems and people, their sensitivity (blue box) and the risk of impacts to ecosystem and human health and societies (red box). Such risks will interact with […]'''
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[[File:3624bb4159db4d4116b86a7ff8e5164e CH_5_20_RGB-3000x2077.jpg]]

Figure 5.20 | The pathways through which scenario of climatic and pollutant hazards (orange boxes) and their interactions can lead to increases in exposure to hazards by the biota, ecosystems and people, their sensitivity (blue box) and the risk of impacts to ecosystem and human health and societies (red box). Such risks will interact with climate-pollutant risk management and policy. The synthesis is based on literature review presented in Alava et al. (2017). Figure adapted from Alava et al. (2017).

Inorganic forms of mercury are more soluble in low pH water, while higher temperature increases mercury uptake and the metabolic activity of bacteria, thereby increasing mercury methylation, uptake by organisms and bioaccumulation rates (Scheuhammer, 1991; Celo et al., 2006; López et al., 2010; Macdonald and Loseto, 2010; Riget et al., 2010; Corbitt et al., 2011; Krabbenhoft and Sunderland, 2013; Roberts et al., 2013; de Orte et al., 2014; McKinney et al., 2015), although there is ''limited evidence'' on the extent of exacerbation by ocean acidification expected in the 21st century. Increased melting of snow and ice from alpine ecosystems and mountains (Chapter 2) can also increase the release of POPs and MeHg from land-based sources into coastal ecosystems (Morrissey et al., 2005). Modelling projections for the Faroe Islands region suggest increased bioaccumulation of methyl mercury under climate change, with an average increases in MeHg concentrations in marine species of 1.6‒1.8% and 4.1‒4.7% under ocean warming scenarios of 0.8°C and 2.0°C, respectively, with an associated increase in potential human intake of mercury beyond levels recommended by the World Health Organization (Booth and Zeller, 2005). Foodweb modeling for the northeastern Pacific projects that concentrations of MeHg and PCBs in top predators could increase by 8% and 3%, respectively, by 2100 under RCP8.5 relative to current levels (Alava et al., 2018). Climate-related pollution risks are of particular concern in Arctic ecosystems and their associated indigenous communities because of the bioaccumulation of POPs and MeHg, causing long-term contamination of traditional seafoods (Marques et al., 2010; Tirado et al., 2010; Alava et al., 2017) of high dietary importance (Cisneros-Montemayor et al., 2016).

Overall, climate change can increase the exposure and bioaccumulation of contaminants and thus the risk of impacts of POPs and MeHg on marine ecosystems and their dependent human communities as suggested by indirect evidence and model simulations (Marques et al., 2010; Tirado et al., 2010; Alava et al., 2017) ( ''high agreement'' ). However, there is ''limited'' ''evidence'' on observed increase in POPs and MeHg due to climate change. Apex predators and human communities that consume them, including Arctic communities and other coastal indigenous populations, are thus vulnerable to increase in exposure to these contaminants and the resulting health effects ( ''medium evidence, medium agreement'' ).

The risk of microplastics has become a major concern for the ocean as they are highly persistent and have accumulated in many different marine environments, including the deep sea (Woodall et al., 2014; GESAMP, 2015; van Sebille et al., 2015; Waller et al., 2017; de Sá et al., 2018; Everaert et al., 2018; Botterell et al., 2019). There is ''limited evidence'' at present to assess their risk to marine ecosystems, wildlife and potentially humans through human consumption of seafood under climate change.

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<span id="food-security"></span>
===== 5.4.2.1.3 Food security =====

Seafood provides protein, fatty acids, vitamins and other micronutrients essential for human health such as iodine and selenium (Golden et al., 2016). Over 4.5 billion people in the world obtain more than 15% of their protein intake from seafood, including algae and marine mammals as well as fish and shellfish (Béné et al., 2015; FAO, 2017)). Around 1.39 billion people obtain at least 20% of their supply of essential micronutrients from fish (Golden et al., 2016). SR15 concluded that global warming poses large risks to food security globally and regionally, especially in low-latitude areas, including fisheries ( ''medium confidence'' ) (Hoegh-Guldberg et al., 2018). This section builds on the assessment on observed and projected climate impacts on fish catches (Section 5.4.1.1) and further assess how such impacts interact with other climatic and non-climatic drivers in affecting food security through fisheries.

Many populations that are already facing challenges in food insecurity reside in low-latitude regions such as in the Pacific Islands and West Africa where maximum fisheries catch potential is projected to decrease under climate change security (Golden et al., 2016; Hilmi et al., 2017) (Section 5.4.1; Figure 5.21) and where land-based food production is also at risk (Blanchard et al., 2017) ( ''medium confidence'' ). Populations in these regions are also estimated to have the highest proportion of their micronutrient intake relative to the total animal sourced food (Golden et al., 2016) (ASF; Figure 5.21). This highlights their strong dependence on seafood as a source of nutrition that further elevates their vulnerability to food security from climate change impacts on seafood supply ( ''high confidence'' ). Modeling of seafood trade networks suggests that Central and West African nations are particularly vulnerable to shocks from decrease in seafood supply from international imports; thus their climate risks of seafood insecurity could be exacerbated by climate impacts on catches and seafood supply elsewhere (Gephart et al., 2016). In addition, experimental studies suggest that warming and ocean acidification reduce the nutritional quality of some seafood by reducing levels of protein, lipid and omega-3 fatty acids (Tate et al., 2017; Ab Lah et al., 2018; Lemasson et al., 2019).

Non-climatic factors may exacerbate climate effects on seafood security. Over-exploitation of fish stocks reduces fish catches (Section 5.4.1.1) (Golden et al., 2016), whilst strong cultural dependence on seafood in many coastal communities may pose constraints in their adaptive capacity to changing fish availability (Marushka et al., 2019). The shift from traditional nutritious wild caught seafood-based diets of coastal indigenous communities, towards increased consumption of processed energy dense foods high in fat, refined sugar and sodium, due to social and economic changes (Kuhnlein and Receveur, 1996; Shannon, 2002; Charlton et al., 2016; Batal et al., 2017), has important consequences on diet quality and nutritional status (Thaman, 1982; Quinn et al., 2012; Luick et al., 2014). This has led to an increased prevalence of obesity, diabetes, and other diet-related chronic diseases (Gracey, 2007; Sheikh et al., 2011) as well as the related decrease in access to culturally or religiously significant food items. The risk of climate change on coastal communities through the ocean could therefore be increased by non-climatic factors such as economic development, trade, effectiveness of resource governance and cultural changes ( ''high confidence'' ).

In summary, the food security of many coastal communities, particularly in low-latitude developing regions, is vulnerable to decreases in seafood supply ( ''medium confidence'' ) because of their strong dependence on seafood to meet their basic nutritional requirements ( ''medium confidence'' ), limited alternative sources of some of the essential nutrients obtained from seafood ( ''medium confidence'' ), and exposure to multiple hazards on their food security ( ''high confidence'' ). Although direct evidence from attribution analysis is not available, climate change may have already contributed to malnutrition by decreasing seafood supply in these vulnerable communities ( ''low confidence'' ) and reduce coastal Indigenous communities’ reliance on seafood-based diets ( ''low confidence'' ). Projected decreases in potential fish catches in tropical areas ( ''high confidence'' ) and a possible decrease in the nutritional content of seafood ( ''low confidence'' ) will further increase the risk of impacts on food security in low-latitude developing regions, with that risk being greater under high emission scenarios ( ''medium confidence'' ).

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'''Figure 5.21'''

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'''Figure 5.21 | Over the ocean the projected changes in catch potential (Section 5.4.1.1), and on land, each countries current proportion of fish micronutrient intake relative to the total animal sourced food (ASF) (Golden et al. 2016). The colour scale on land is the proportion of fish micronutrient intake relative to the total ASF; the […]'''
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[[File:53e7771cb08d06311a22bb6ab94cd184 IPCC-SROCC-CH_5_21-2.jpg]]

Figure 5.21 | Over the ocean the projected changes in catch potential (Section 5.4.1.1), and on land, each countries current proportion of fish micronutrient intake relative to the total animal sourced food (ASF) (Golden et al. 2016). The colour scale on land is the proportion of fish micronutrient intake relative to the total ASF; the scale on the ocean is projected change in maximum catch potential under Representative Concentration Pathway (RCP)8.5 by 2100 relative to the 2000s.

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<div id="section-5-4-2-2cultural-and-other-social-dimensions"></div>

<span id="cultural-and-other-social-dimensions"></span>
==== 5.4.2.2 Cultural and Other Social Dimensions ====

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<span id="cultural-and-aesthetic-values"></span>
===== 5.4.2.2.1 Cultural and aesthetic values =====

Climate change threatens key cultural dimensions of lives and livelihoods (Adger et al., 2012 <sup>[[#fn:r1459|1459]]</sup> ), because people develop strong cultural ties and associate distinctive meanings with many natural places and biota in the form of traditions, customs and ways of life (Marshall et al., 2018 <sup>[[#fn:r1460|1460]]</sup> ). These impacts have been felt both by indigenous and non-indigenous peoples. Recent estimates suggest that there are more than 1900 indigenous groups along the coastline with around 27 million people across 87 countries (Cisneros-Montemayor et al., 2016 <sup>[[#fn:r1461|1461]]</sup> ). AR5 concluded that climate change will affect the harvests of marine species with spiritual and aesthetic importance to indigenous cultures (Pörtner et al., 2014 <sup>[[#fn:r1462|1462]]</sup> ). This section further assesses the effects of climate change on Indigenous knowledge and local knowledge and their transmission and the implication for well-being of people, complementing the assessment for Arctic indigenous people in Chapter 3.

Indigenous knowledge is passed and appreciated over timeframes ranging from several generations to a few centuries (Cross Chapter Box 4 in Chapter 1). The adjustment of the transmission and the network of Indigenous knowledge on the ocean and coasts, and related perceptions and practice, implies a reworking of these knowledge systems where the individuals and the groups are actors in a narrative and historical construction (Roué, 2012 <sup>[[#fn:r1463|1463]]</sup> ; Alderson-Day et al., 2015 <sup>[[#fn:r1464|1464]]</sup> ). SLR is already transforming the seascape, such as the shape of shores in many low-lying islands in the Pacific, leading to modification or disappearance of geomorphological features that represent gods and mythological ancestors (Camus, 2017 <sup>[[#fn:r1465|1465]]</sup> ; Kench et al., 2018 <sup>[[#fn:r1466|1466]]</sup> ). These changing seascape also affects the mobility of people and residence patterns, and consequently, the structure and transmission of Indigenous knowledge (Camus, 2017 <sup>[[#fn:r1467|1467]]</sup> ). The fear of SLR and climate change encourage security measures and the grouping of local people to the safest places, contributing to the erosion of indigenous culture and their knowledge about the ocean (Bambridge and Le Meur, 2018 <sup>[[#fn:r1468|1468]]</sup> ), and impairment of opportunity for social elevation for some Pacific indigenous communities (Borthwick, 2016 <sup>[[#fn:r1469|1469]]</sup> ).

Climate change is also projected to shift the biogeography and potential catches of fishes and invertebrates (5.2.3.1, 5.3, 5.4.1.1) that form an integral part of the culture, economy and diet of many indigenous communities, such as those situated along the Pacific Coast of North America (Lynn et al., 2013 <sup>[[#fn:r1470|1470]]</sup> ). Indigenous fishing communities that depend on traditional marine resources for food and economic security are particularly vulnerable to climate change through reduced capacity to conduct traditional harvests because of reduced access to, or availability of, resources (Larsen et al., 2014 <sup>[[#fn:r1471|1471]]</sup> ; Weatherdon et al., 2016 <sup>[[#fn:r1472|1472]]</sup> ). Overall, the transmission of indigenous culture and knowledge is at risk because of SLR affecting sea- and land-scapes, the availability and access to culturally important marine species, and communities’ reliance on the ocean for their livelihood and their cultural beliefs ( ''medium confidence'' ). Strong attachment to traditional marine-based livelihoods has also been reported for non-indigenous communities in Canada (Davis, 2015), the USA (Paolisso et al., 2012 <sup>[[#fn:r1474|1474]]</sup> ), Spain (Ruiz et al., 2012 <sup>[[#fn:r1475|1475]]</sup> ) and Australia (Metcalf et al., 2015 <sup>[[#fn:r1476|1476]]</sup> ). Reduction in populations of fish species that have supported livelihoods for generations, and deteriorations of iconic elements of seascapes are putting the well-being of these communities at risk ( ''high confidence'' ).

Other cultural values supported by the ocean are diverse. They include education, based on knowledge of marine environments. Such education can increase knowledge and awareness of climate change impacts and the efficacy of their mitigation (Meadows, 2011 <sup>[[#fn:r1477|1477]]</sup> ); it can also influence the extent to which stewardship activities are adopted (von Heland et al., 2014; Wynveen and Sutton, 2015 <sup>[[#fn:r1478|1478]]</sup> ; Bennett et al., 2018 <sup>[[#fn:r1479|1479]]</sup> ), and can help develop new networks between coastal people and environmental managers for the purposes of planning and implementing new adaptation strategies (Wynveen and Sutton, 2015 <sup>[[#fn:r1480|1480]]</sup> ). A critical element in reducing vulnerability to climate change is to educate people that they are an integral part of the Earth system and have a huge influence on the balance of the system. An important marine ecosystem service is to support such education (Malone, 2016 <sup>[[#fn:r1481|1481]]</sup> ). Thus, education can play a pivotal role in how climate change is perceived and experienced, and marine biodiversity and ecosystems play an important role in this. At the same time, climate change impacts on marine ecosystems (Sections 5.2.3, 5.2.4) can affect the role of the ocean in supporting such public education ( ''medium evidence, high agreement, medium confidence'' ).

The aesthetic appreciation of natural places is one of the fundamental ways in which people relate to their environment. AR5 noted that climate change may impact marine species with aesthetic importance that affect local and indigenous cultures, local economies and challenge cultural preservation (Pörtner et al., 2014 <sup>[[#fn:r1482|1482]]</sup> ). Evidence since AR5 confirms that aesthetically appreciated aspects of marine ecosystems are important for supporting local and international economies (especially through tourism), human well-being, and stewardship. For example, Marshall et al. (2018) found that aesthetic values are a critically important cultural value for all cultural groups, and are important for maintaining sense of place, pride, identity and opportunities for inspiration, spirituality, recreation and well-being. However, climate change induced degradation and loss of biodiversity and habitats (Section 5.2.3, 5.2.4, 5.3) can also negatively impact the ecosystem features that are currently appreciated by human communities, such as coral reefs, mangroves, charismatic species (such as some marine mammals and seabirds) and geomorphological features (e.g., sandy beaches). There are also aesthetic and inspirational values of marine biodiversity and ecosystems that are important to the psychological and spiritual well-being of people, including film, literature, art and recreation (Pescaroli and Magni, 2015 <sup>[[#fn:r1483|1483]]</sup> ). Other cultural dimensions that are becoming more widely acknowledged as potentially disturbed by climate change include the appreciation of scientific, artistic, spiritual, and health opportunities, as well as appreciation of biodiversity, lifestyle and aesthetics (Marshall et al., 2018 <sup>[[#fn:r1484|1484]]</sup> ). Thus, climate change may also affect the way in which marine ecosystems support human well-being through cultural dimensions. However, the difficulties in evaluating the importance of aesthetic aspects of marine ecosystems, and in detecting and attributing of climate change impacts, result in such assessment having ''low confidence'' .

Climate change affects human cultures and well-being differently. For example, Marshall et al. (2018) <sup>[[#fn:r1485|1485]]</sup> assessed the importance of identity, pride, place, aesthetics, biodiversity, lifestyle, scientific value and well-being within the Great Barrier Reef region by 8,300 people across multiple cultural groups. These groups included indigenous and non-indigenous local residents, Australians (non-local), international and domestic tourists, tourism operators, and commercial fishers. They found that all groups highly rated all (listed) cultural values, suggesting that these values are critically associated with iconic ecosystems. Climate change impacts upon the Great Barrier Reef, through increased temperatures, cyclones and SLR that cumulatively degrade the quality of the Reef, are therefore liable to result in cultural impacts for all groups. However, survey that assess the emotional responses to degradation of the Great Barrier Reef by similar stakeholder groups reported different levels of impacts among these groups (Marshall et al., 2019 <sup>[[#fn:r1486|1486]]</sup> ). Therefore, many ocean and coastal dependent communities value marine ecosystems highly and climate impacts can affect their well-being, although the sensitivity to such impacts can vary among stakeholder groups (Marshall et al., 2019 <sup>[[#fn:r1487|1487]]</sup> ) ( ''low confidence'' ).

Climate change may alter the environment too rapidly for cultural adaptation to keep pace. This is because the culture that forms around a natural environment can be so integral to people’s lives that disassociation from that environment can induce a sense of disorientation and disempowerment (Fisher and Brown, 2015 <sup>[[#fn:r1488|1488]]</sup> ). The adaptive capacity of people to moderate or influence cultural impacts, and thereby reduce vulnerability to such impacts, is also culturally determined (Cinner et al., 2018 <sup>[[#fn:r1489|1489]]</sup> ). For example, when a resource user such as a fisher, farmer, or forester is suddenly faced with the prospect that their resource-based occupation is no longer viable, they lose not only a means of earning an income but also an important part of their identity (Marshall et al., 2012 <sup>[[#fn:r1490|1490]]</sup> ; Tidball, 2012 <sup>[[#fn:r1491|1491]]</sup> ). Loss of identity can, in turn, have severe economic, psychological and cultural impacts (Turner et al., 2008 <sup>[[#fn:r1492|1492]]</sup> ). Climate change can quickly alter the quality of, or access to, a natural resource through degradation or coastal inundation, so that livelihoods and lifestyles are no longer able to be supported by that resource. When people are displaced from places that they value, there is strong evidence that their cultures are diminished, and in many cases endangered. There are no effective substitutions for, or adequate compensation for, lost sites of significance (Adger et al., 2012 <sup>[[#fn:r1493|1493]]</sup> ). As sensitive marine ecosystems such as coral reefs and kelp forest are impacted by climate change at rapid rate (Section 5.3), these can lead to the loss of part of people’s cultural identity and values beyond the rate at which identify and values can be adjusted or substituted ( ''medium confidence'' ).

<div id="section-5-4-2-2cultural-and-other-social-dimensions-block-2"></div>

<span id="potential-conflicts-in-resource-utilisation"></span>
===== 5.4.2.2.2 Potential conflicts in resource utilisation =====

Redistribution of marine species in response to direct and indirect effects of climate change may also disrupt existing marine resource sharing and associated governance (Miller and Russ, 2014 <sup>[[#fn:r1494|1494]]</sup> ; Pinsky et al., 2018 <sup>[[#fn:r1495|1495]]</sup> ). These effects have contributed to disputes in international fisheries management for North Atlantic mackerel (Spijkers and Boonstra, 2017 <sup>[[#fn:r1496|1496]]</sup> ) and Pacific salmon (Miller and Russ, 2014 <sup>[[#fn:r1497|1497]]</sup> ). These disagreements have stressed diplomatic relations in some cases (Pinsky et al., 2018 <sup>[[#fn:r1498|1498]]</sup> ). Decreases and fluctuations in fish stock abundance and fish catches have also contributed to past disputes (Belhabib et al., 2016 <sup>[[#fn:r1499|1499]]</sup> ; Pomeroy et al., 2016 <sup>[[#fn:r1500|1500]]</sup> ; Blasiak et al., 2017 <sup>[[#fn:r1501|1501]]</sup> ). Under climate change, shifts in abundance and distribution of fish stocks are projected to intensify in the 21st century (Sections 5.2.3, 5.3, 5.4.1.1). Stocks may locally increase and decrease elsewhere. New or increased fishing opportunities may be created when exploited fish stocks shift their distribution into a country’s waters where their abundance was previously too low to support viable fisheries (Pinsky et al., 2018 <sup>[[#fn:r1502|1502]]</sup> ). The number of new transboundary stocks occurring in exclusive economic zones worldwide was projected to be around 46 and 60 under RCP2.6 and RCP8.5, respectively, by 2060 relative to 1950‒2014 (Pinsky et al., 2018 <sup>[[#fn:r1503|1503]]</sup> ). However, such alteration of the sharing of resources between countries would challenge existing international fisheries governance regimes and, without sufficient adaptation responses, increase the potential for disputes in resource allocation and management (Belhabib et al., 2018 <sup>[[#fn:r1504|1504]]</sup> ; Pinsky et al., 2018 <sup>[[#fn:r1505|1505]]</sup> ). Overall, projected climate change impacts on fisheries in the 21st century increase the risk of potential conflicts among fishery area users and authorities or between two different communities within the same country (Ndhlovu et al., 2017 <sup>[[#fn:r1506|1506]]</sup> ; Shaffril et al., 2017 <sup>[[#fn:r1507|1507]]</sup> ; Spijkers and Boonstra, 2017 <sup>[[#fn:r1508|1508]]</sup> ) ( ''medium confidence'' ), exacerbated through competing resource exploitation from international actors and mal-adapted policies ( ''low confidence'' ). Such risks can be reduced by appropriate fisheries governance responses that are discussed in Sections 5.5.2 and 5.5.3.

<div id="section-5-4-2-3monetary-and-material-wealth"></div>

<span id="monetary-and-material-wealth"></span>
==== 5.4.2.3 Monetary and Material Wealth ====

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<span id="wealth-generated-from-fisheries"></span>
===== 5.4.2.3.1 Wealth generated from fisheries =====

Global gross revenues from marine fisheries were around 150 billion in 2010 USD (Swartz et al., 2013; Tai et al., 2017). Capture fisheries provide full-time and part-time jobs for an estimated 260 ± 6 million people in the 2000s period, of whom 22 ± 0.45 million are small ‐ scale fishers (Teh and Sumaila, 2013 <sup>[[#fn:r1511|1511]]</sup> ). Small-scale fisheries are important for the livelihood and viability of coastal communities worldwide (Chuenpagdee, 2011 <sup>[[#fn:r1512|1512]]</sup> ). AR5 concluded with ''low confidence'' that climate change will lead to a global decrease in revenue with regional differences that are driven by spatial variations of climate impacts on and the flexibility and capacities of food production systems (Pörtner et al., 2014 <sup>[[#fn:r1513|1513]]</sup> ). AR5 also highlighted the high vulnerability of mollusc aquaculture to ocean acidification. For example, the oyster industry in the Pacific has lost nearly 110 million USD in annual revenue due to ocean acidification (Ekstrom et al., 2015 <sup>[[#fn:r1514|1514]]</sup> ). This section examines the rapidly growing literature assessing the risks of climate change on fisheries and aquaculture sectors, and the potential interaction between climatic and non-climatic drivers on the economics of fisheries. However, new evidence on observed economic impacts of climate change on fisheries since AR5 is limited.

Since AR5, projections on climate change impacts on the economics of marine fisheries have incorporated a broader range of social-economic considerations. Driven by shifts in species distributions and maximum catch potential of fish stocks (Section 5.4.1), if the ex-vessel price of catches remains the same, marine fisheries maximum revenue potential are projected to be negatively impacted in 89% of the world’s fishing countries under the RCP8.5 scenario by the 2050s relative to the current status, with projected global decreases of 10.4 ± 4.2% and 7.1 ± 3.5% under RCP8.5 and RCP2.6, respectively, by 2050 relative to 2000 (Lam et al., 2016). While the projected changes in revenues are sensitive to price scenarios (Lam et al., 2016 <sup>[[#fn:r1515|1515]]</sup> ), future maximum revenue potential is reduced under high emission scenarios (Sumaila et al., 2019 <sup>[[#fn:r1517|1517]]</sup> ). For example, when the elasticity of seafood price in relation to their supply was modelled explicitly, fisheries maximum revenue potential under a 1.5°C atmospheric warming scenario was projected to be higher than for 3.5°C warming by 7.4% (13.1 billion USD) ± 2.3%, across projections from three CMIP5 models (Sumaila et al., 2019 <sup>[[#fn:r1518|1518]]</sup> ). Accounting for the subsequent impacts on the dependent communities and relative to the 1.5°C warming scenario, that study also projected a decrease in seafood workers’ incomes of 7.8% (3.7 billion USD) ± 2.3% and an increase in households’ seafood expenditure by the global population of 3.2% (6.3 billion USD) ± 3.9% annually under a 3.5°C warming scenario (Sumaila et al., 2019 <sup>[[#fn:r1519|1519]]</sup> ).

Fisheries management strategies and fishing effort affect the realised catch and economic benefits of fishing (Barange, 2019 <sup>[[#fn:r1520|1520]]</sup> ). Modelling analysis of fish stocks with available data worldwide showed that for RCP6.0, adaptation of fisheries by accommodating shifts in species distribution and abundance, as well as rebuilding existing overexploited or depleted fish stocks, is projected to lead to substantially higher global profits (154%), harvest (34%), and biomass (60%) in the future, relative to a no adaptation scenario. However, the total profit, harvest and biomass are negatively affected even with the full adaptation scenario under RCP8.5 (Gaines et al., 2018 <sup>[[#fn:r1521|1521]]</sup> ). Overall, climate change impacts on the abundance, distribution and potential catches of fish stocks (see Section 5.3.1) are expected to reduce the maximum potential revenues of global fisheries ( ''high agreement, medium evidence, medium confidence'' ). These impacts on fisheries will increase the risk of impacts on the income and livelihoods of people working in these economic sectors by 2050 under high greenhouse gas emission scenarios relative to low emission scenario ( ''high confidence'' ). Rebuilding overexploited or depleted fisheries can help improve economic efficiency and reduce climate risk, provided that emissions are greatly reduced ( ''medium confidence'' ).

The economic implications of climate change on fisheries vary between regions and countries because of the differences in exposure to revenue changes and the sensitivity and adaptive capacity of the fishing communities to these changes (Hilmi et al., 2015 <sup>[[#fn:r1522|1522]]</sup> ). Regions where the maximum potential revenue is projected to decrease coincide with areas where indicators such as human development index suggest high economic vulnerability to climate change (Barbier, 2015 <sup>[[#fn:r1523|1523]]</sup> ; Lam et al., 2016 <sup>[[#fn:r1524|1524]]</sup> ). Many coastal communities in these regions rely heavily on fish and fisheries as a major source of animal proteins, nutritional needs, income and job opportunities (FAO, 2019). Negative impacts on the catch and total fisheries revenues for these countries are expected to have greater implications for jobs, economies, food and nutritional security than the impacts on regions with high Human Development Index (Allison et al., 2009 <sup>[[#fn:r1525|1525]]</sup> ; Srinivasan et al., 2010 <sup>[[#fn:r1526|1526]]</sup> ; Golden et al., 2016 <sup>[[#fn:r1527|1527]]</sup> ; Blasiak et al., 2017 <sup>[[#fn:r1528|1528]]</sup> ). Climate change impacts to coral reefs and other fish habitats, as well as to targeted fish and invertebrate species themselves are expected to reduce harvests from small-scale, coastal fisheries by up to 20% by 2050, and by up to 50% by 2100, under RCP8.5 (Bell et al., 2018a <sup>[[#fn:r1529|1529]]</sup> ). Therefore, climate risk to communities that are strongly dependent on fisheries associated with ecosystems that are particularly sensitive to climate change such as coral reefs will have be particularly high (Cinner et al., 2016 <sup>[[#fn:r1530|1530]]</sup> ) ( ''high confidence'' ).

Climate change may also worsen non-climate related socioeconomic shocks and stresses, and hence is an obstacle to economic developments (Hallegatte et al., 2015 <sup>[[#fn:r1531|1531]]</sup> ). Climate risk on the economics of fishing is projected to be higher for tropical developing countries where existing adaptive capacity to the risk is lower, thereby challenging their sustainable economic development ( ''high confidence'' ). However, observed impacts are not yet well documented (Lacoue-Labarthe et al., 2016 <sup>[[#fn:r1532|1532]]</sup> ) , and there are many uncertainties relating to how climate change would affect the dynamics of fishing costs, with consequent adjustment of fishing effort that might intensify or lessen the overcapacity issue. Studies have attempted to project how fishers may respond to changes in fish distribution and abundance by incorporating different management systems (Haynie and Pfeiffer, 2012 <sup>[[#fn:r1533|1533]]</sup> ; Galbraith et al., 2017 <sup>[[#fn:r1534|1534]]</sup> ). However, the impacts of climate change on management effectiveness and trade practices is still inadequately understood (Galbraith et al., 2017 <sup>[[#fn:r1535|1535]]</sup> ).

<div id="section-5-4-2-3monetary-and-material-wealth-block-2"></div>

<span id="wealth-generated-from-coastal-and-marine-tourism-sector"></span>
===== 5.4.2.3.2 Wealth generated from coastal and marine tourism sector =====

Tourism is one of the largest sectors in the global economy. Between 1995‒1998 and 2011‒2014, the average total contribution of tourism to global GDP increased from 69 billion USD (6.8%) to 166 billion USD (8.5%) respectively, and generated more than 21 million jobs between 2011‒2014 (UNCTAD, 2018 <sup>[[#fn:r1536|1536]]</sup> ). Coastal tourism and other marine-related recreational activities contributes substantially to the tourism sector (Cisneros-Montemayor et al., 2013 <sup>[[#fn:r1537|1537]]</sup> ; O’Malley et al., 2013 <sup>[[#fn:r1538|1538]]</sup> ; Spalding et al., 2017 <sup>[[#fn:r1539|1539]]</sup> ; Giorgio et al., 2018 <sup>[[#fn:r1540|1540]]</sup> ; UNWTO, 2018 <sup>[[#fn:r1541|1541]]</sup> ). For example, it is estimated that around 121 million people a year participated in marine-based recreational activities, generating  47 billion in 2003 USD in expenditures and supporting one million jobs (Cisneros-Montemayor and Sumaila, 2010 <sup>[[#fn:r1542|1542]]</sup> ). Tourism is one of the main industries that provides opportunities for social and economic development (Jiang and DeLacy, 2014 <sup>[[#fn:r1543|1543]]</sup> ), and marine tourism is particularly important for many coastal developing countries and Small Island Developing States (SIDS). AR5 identified the tourism sector in the Caribbean region as particularly vulnerable to climate change effects, due to hurricanes, whilst SR15 concluded that warming will directly affect climate-dependent tourism markets on a worldwide basis ( ''medium confidence'' ) (Hoegh-Guldberg et al., 2018 <sup>[[#fn:r1544|1544]]</sup> ). This assessment provides updates since AR5 and SR15.

Empirical modelling of future risks to tourism is based on projected climate impacts (Section 5.3) for relevant coastal ecosystems, including degradation or loss of beach and coral reef assets (Weatherdon et al., 2016 <sup>[[#fn:r1545|1545]]</sup> ) (Section 4.3.3.6.2). These projections are developed from the relationship between the economic benefits generated from coral reef related tourism with observed characteristics of coral reefs, the characteristics of tourism activities. Based on scenarios of projected future warming and decreases in coral reef coverage, a global loss of tourism and recreation value in the near-future (2031‒2050) of 2.57–2.95 billion yr -1 in 2000 USD is projected under RCP2.6, and of 3.88‒5.80 billion yr -1 in 2000 USD under RCP8.5 (Chen et al., 2015 <sup>[[#fn:r1546|1546]]</sup> ). Opinion surveys in four countries suggest that if severe coral bleaching persists in the Great Barrier Reef, tourism in adjacent areas could greatly decline, from 2.8 million to around 1.7 million visitors per year, equivalent to more than 1 billion AUS (~0.69 billion USD using exchange rate in 2019), that is, in tourism expenditure and with potential loss of around 10,000 jobs (Swann and Campbell, 2016 <sup>[[#fn:r1547|1547]]</sup> ).

Many coastal tourism destinations are exposed to risks of flooding, SLR and coastal squeeze on coastal ecosystems (Lithgow et al., 2019 <sup>[[#fn:r1548|1548]]</sup> ) (Section 5.3); there are also other climate related-risks. Droughts, which are projected to be more frequent, will also impact the tourism industry (and local food security) through water and food shortages (Pearce et al., 2018 <sup>[[#fn:r1549|1549]]</sup> ). If climate change and ocean acidification reduce the seafood supply, the attractiveness of coastal regions for tourists will also decrease (Wabnitz et al., 2017 <sup>[[#fn:r1550|1550]]</sup> ). North Atlantic hurricanes and tropical storms have increased in intensity over the last 30 years, with climate projections indicating an increasing trend in hurricane intensity (Chapter 6). Three major Caribbean storms, Harvey, Irma and Maria, occurred in 2017, with loss and damage to the tourism industries of Dominica, the British Virgin Islands, and Antigua and Barbuda estimated at 2.2 billion USD, and environmental recovery costs estimated at 6.8 million USD (UNDP, 2017 <sup>[[#fn:r1551|1551]]</sup> ). Pacific tourist destinations, which tend to focus on nature-based and marine activities, are also at high risk of extreme events and other climate change impacts (Klint et al., 2015 <sup>[[#fn:r1552|1552]]</sup> ). However, global tourism has a high carbon footprint (flights, cruises, etc.) (Lenzen et al., 2018 <sup>[[#fn:r1553|1553]]</sup> ), so any reduction in the intensity of this sector would help mitigate climate change.

Evidence from recent studies on projected climate risks on recreational fishing is equivocal, with the direction of impacts depending on the location, species targeted and societal context. For example: poleward range shifts of marine fish (Section 5.2.3) could yield new opportunities for recreational fishing in mid- to high-latitude regions (DiSegni and Shechter, 2013 <sup>[[#fn:r1554|1554]]</sup> ); projected increases in air temperature may enable longer fishing days in some area (Dundas and von Haefen, 2015 <sup>[[#fn:r1555|1555]]</sup> ); and extreme events may alter the composition of recreational fishing catches (Santos et al., 2016 <sup>[[#fn:r1556|1556]]</sup> ). Since climate risks to recreational fishing vary largely depending on the responses of the targeted species to climate-related pressures, there is ''low confidence'' in the overall risk to the activity.

Overall, evidence since AR5 and SR15 confirms that climate impacts to coastal ecosystems would increase risks to coastal tourism, particularly under high emission scenarios ( ''medium confidence'' ). Economic impacts will be greatest for those developing countries where tourism is the main source of foreign revenue ( ''medium'' to ''high evidence'' ).

<div id="section-5-4-2-3monetary-and-material-wealth-block-3"></div>

<span id="property-values"></span>
===== 5.4.2.3.3 Property values =====

The integrity of ecosystems and their services can affect the value of human assets, particularly coastal properties and infrastructure (Hoegh-Guldberg et al., 2018 <sup>[[#fn:r1557|1557]]</sup> ). Climate change is expected to have negative impacts on coastal properties and their value through the loss and damage caused by SLR, increased storm intensity (hurricanes and cyclones), heat waves, floods, droughts and other extreme events, particularly in tropical SIDS (Chapter 4). Natural disasters already cost Pacific Island Countries and Territories between 0.5‒6.6% of GDP yr -1 (World Bank, 2017 <sup>[[#fn:r1558|1558]]</sup> ), with localised damages and losses from individual storms far exceeding these estimates (e.g., 64% of Vanuatu’s GDP for Cyclone Pam in 2015). The impacts of natural disasters on Jamaica’s coastal transport infrastructure are currently estimated to be a significant proportion of their GDP, and such costs are projected to increase substantially in the next few decades under climate change (UNCTAD, 2017 <sup>[[#fn:r1559|1559]]</sup> ; Monioudi et al., 2018 <sup>[[#fn:r1560|1560]]</sup> ). In 2015, tropical storm Erika devastated Dominica causing 483 million USD in damages and losses (mostly related to transport, housing and agriculture), equivalent to 90% of Dominica’s GDP (World Bank, 2017 <sup>[[#fn:r1561|1561]]</sup> ). For the USA, Ackerman and Stanton (2007) forecast that annual real estate losses due to climate change could increase from 0.17% of GDP in 2025 to 0.36% in 2100, with Atlantic and Gulf Coast states being the most vulnerable. Other North American studies have shown that informed coastal property owners are willing to initially invest in infrastructure to counter climate change impacts (McNamara and Keeler, 2013 <sup>[[#fn:r1562|1562]]</sup> ); however, they would avoid further investment if adaptation costs increase substantially and there are greater risks of long-term impacts (Putra et al., 2015 <sup>[[#fn:r1563|1563]]</sup> ).

The impacts of changing marine ecosystems and ecosystem services on the value of human assets need to consider the risk perception, future development and adaptation responses of human communities (Section 5.5.2, Chapter 4) (Bunten and Kahn, 2014 <sup>[[#fn:r1564|1564]]</sup> ). For example, the potential for climate impacts on the value of coastal real estate will depend on the changing insurance market or the cost of adaptation measures, which in turn depend on the willingness to pay by asset holders and wider society, including local and national governments. Further research is needed to discount valuations for potential losses that may occur in the future but with uncertain occurrence, and to improve real estate loss estimates over local to regional scales.

Marine ecosystem services contribute to climate moderation and coastal defenses (Section 5.4.1.2). However, while the above studies in this section acknowledge the contribution of many climate impacts on real estate and infrastructure through ecosystem losses and degradation, often they are not accounted for in quantitative economic impact assessments. Overall, there is ''high confidence'' that SLR, increases in storm intensity and other extreme events will impact the values of coastal real estates and infrastructure, particularly in tropical SIDS, through the risk and impacts of direct physical damages. However, there is ''low confidence'' that impacts due to underlying loss and damage of ecosystems and their services are being similarly accounted for.

<div id="section-5-4-2-4risk-and-opportunities-for-ocean-economy"></div>

<span id="risk-and-opportunities-for-ocean-economy"></span>
==== 5.4.2.4 Risk and Opportunities for Ocean Economy ====

<div id="section-5-4-2-4risk-and-opportunities-for-ocean-economy-block-1"></div>

The ‘ocean economy’ refers to the sustainable use of ocean resources for economic growth, improved livelihoods and jobs, and ocean ecosystem health (World Bank, 2017 <sup>[[#fn:r1565|1565]]</sup> ). In SR15 (Hoegh-Guldberg et al., 2018 <sup>[[#fn:r1566|1566]]</sup> ) and elsewhere here (Chapters 3 and 5), the risks and opportunities of specific sectors that contribute to the ocean economy under climate change are assessed. The fishing industry is particularly important in this context. As previously noted, warming has already directly impacted coastal and open ocean fishing activities in some regions (Section 5.4.1.1, 5.4.2.3.1); the risk of fishery impacts is exacerbated by the observed climate-driven changes to coral reefs and other coastal ecosystems that contribute to the productivity of exploited fish species (Section 5.4.1.3, 5.4.2.3.1); and there are challenges to sustainable management of transboundary fisheries resources caused by species’ range shifts and associated governance challenges (Section 5.4.2.2.2).

Fisheries-related national and local economies of many tropical developing countries are exposed high climate risks (Section 5.4.2.3.1) (Blasiak et al., 2017 <sup>[[#fn:r1567|1567]]</sup> ), as a result of the projected large decrease in maximum catch and revenue potential under RCP8.5 in the 21st century (Section 5.4.1.1). Historical examples from fishery over-exploitation indicate that a large decrease in catches for specific fish stocks have had substantial negative effects for dependent economies and communities (Brierley and Kingsford, 2009 <sup>[[#fn:r1568|1568]]</sup> ; Davis, 2015 <sup>[[#fn:r1569|1569]]</sup> ). Moreover, coastal economies that are dependent on marine tourism and recreational activities are also exposed to elevated risks from impacts on biota that are important for these sectors (Section 5.4.2.3.2). Nevertheless, new opportunities for coastal tourism may occur in future for some regions as a result of species’ biogeographic shifts (Section 5.4.2.3.2) and increased accessibility, such as in the Arctic (Chapter 3).

Decrease in sea ice in the Arctic is opening up economic opportunities for the oil and gas exploration, mining industries and shipping that are currently important economic sectors in the ocean (Pelletier and Guy, 2012 <sup>[[#fn:r1570|1570]]</sup> ; George, 2013 <sup>[[#fn:r1571|1571]]</sup> ) (Section 3.4.3; 3.5.3). Although the Arctic region has oil and gas reserves estimated to account for one-tenth of world oil and a quarter of global gas ( ''U.S. Geological Survey released on 24 July 2008'' ), offshore oil and gas exploration with poor regulation or as a result of accidents poses additional risk of impacts on species, populations, assemblages, to ecosystems by modifying a variety of ecological parameters (e.g., biodiversity, biomass, and productivity) (Cordes et al., 2016 <sup>[[#fn:r1572|1572]]</sup> ) threatening the sensitive Arctic ecosystems and the livelihood of dependent communities (Section 3.5.3.3).

Similarly, global warming and changing weather patterns may have a substantial impact on global trade and transport pathways (Koetse and Rietveld, 2009 <sup>[[#fn:r1573|1573]]</sup> ); for example, the reduction in sea ice in the Arctic Ocean during summer opens up the possibility for sea transport on the Northwest or Northeast Passage for several months per year (Ng et al., 2018 <sup>[[#fn:r1574|1574]]</sup> ) (Section 3.5.3.2). Both routes may provide opportunities for more efficient transport between North America, Europe, Russia and China for fleets with established Arctic equipment, and may open up access to known natural resources which have so far been covered by ice (Guy and Lasserre, 2016 <sup>[[#fn:r1575|1575]]</sup> ). However, whether the Arctic shipping routes will be a realistic alternative depends not only on regulatory frameworks and economic aspects (such as infrastructure and reliability of the routes) but also on societal trends and values, demographics and tourism demand (Prowse et al., 2009 <sup>[[#fn:r1576|1576]]</sup> ; Wassmann et al., 2010 <sup>[[#fn:r1577|1577]]</sup> ; Pelletier and Guy, 2012 <sup>[[#fn:r1578|1578]]</sup> ; George, 2013 <sup>[[#fn:r1579|1579]]</sup> ; Hodgson et al., 2016 <sup>[[#fn:r1580|1580]]</sup> ; Pizzolato et al., 2016 <sup>[[#fn:r1581|1581]]</sup> ; Dawson, 2017 <sup>[[#fn:r1582|1582]]</sup> ) (Section 3.2.4.2, 3.4.3.3). Simultaneously, shipping routes through the Arctic pose additional risk from human impact such as pollution, introduction of invasive species and collision with marine mammals, and emission of short-lived climate forcers that can amplify warming in the region and accelerate localised warming (Wan et al., 2016 <sup>[[#fn:r1583|1583]]</sup> ) (Section 3.5.3.2).

Existing governance may not be sufficient to limit the elevated risk on Arctic ecosystems and their dependent economies from increased shipping activities (Section 3.4.3, 3.5.3). Climate change may bring new economic opportunities, particularly for polar oil and gas development ( ''medium confidence'' ), shipping ( ''medium confidence'' ) and tourism ( ''low confidence'' ) although realisation of these opportunities will pose uncertain ecological risks to sensitive ecosystems and biota, and the dependent human communities in the region ( ''high confidence'' ).

Ocean renewable energy provides an emerging alternative to fossil fuels and comprises energy extraction from offshore winds, tides, waves, ocean thermal gradients, currents and salinity gradients (Harrison and Wallace, 2005 <sup>[[#fn:r1584|1584]]</sup> ; Koetse and Rietveld, 2009 <sup>[[#fn:r1585|1585]]</sup> ; Bae et al., 2010 <sup>[[#fn:r1586|1586]]</sup> ; Jaroszweski et al., 2010 <sup>[[#fn:r1587|1587]]</sup> ; O Rourke et al., 2010 <sup>[[#fn:r1588|1588]]</sup> ; Hooper and Austen, 2013 <sup>[[#fn:r1589|1589]]</sup> ; Kempener and Neumann, 2014b <sup>[[#fn:r1590|1590]]</sup> ; Kempener and Neumann, 2014a <sup>[[#fn:r1591|1591]]</sup> ; Abanades et al., 2015 <sup>[[#fn:r1592|1592]]</sup> ; Astariz et al., 2015 <sup>[[#fn:r1593|1593]]</sup> ; Borthwick, 2016 <sup>[[#fn:r1594|1594]]</sup> ; Foteinis and Tsoutsos, 2017 <sup>[[#fn:r1595|1595]]</sup> ; Manasseh et al., 2017 <sup>[[#fn:r1596|1596]]</sup> ; Becker et al., 2018 <sup>[[#fn:r1597|1597]]</sup> ; Gattuso et al., 2018 <sup>[[#fn:r1598|1598]]</sup> ; Hemer et al., 2018 <sup>[[#fn:r1599|1599]]</sup> ; Dinh and McKeogh, 2019b <sup>[[#fn:r1600|1600]]</sup> ; Dinh and McKeogh, 2019a <sup>[[#fn:r1601|1601]]</sup> ). Other potential sources of marine renewable energy include algal biofuels (Greene et al., 2010 <sup>[[#fn:r1602|1602]]</sup> ; Greene et al., 2016 <sup>[[#fn:r1603|1603]]</sup> ). While such approaches offers a way to mitigate climate change, changes in climatic conditions (such as waves and winds) may impact marine renewable energy installations and their effectiveness (Harrison and Wallace, 2005 <sup>[[#fn:r1604|1604]]</sup> ). A more comprehensive assessment of these issues is expected to be provided by IPCC WGIII in the AR6 full report.

Overall, some major existing ocean economy sectors such as fishing, coastal tourism and recreation are already at risk by climate change ( ''medium confidence'' ), and all sectors are expected to have elevated risks with high future emission scenarios ( ''high confidence'' ). The emerging demand for alternative energy sources is expected to generate economic opportunities for the ocean renewable energy section ( ''high confidence'' ), although their potential may also be affected by climate change ( ''low confidence'' ).

<div id="section-5-4-2-5impacts-of-changing-ocean-on-sustainable-development-goals"></div>

<span id="impacts-of-changing-ocean-on-sustainable-development-goals"></span>
==== 5.4.2.5 Impacts of Changing Ocean on Sustainable Development Goals ====

<div id="section-5-4-2-5impacts-of-changing-ocean-on-sustainable-development-goals-block-1"></div>

Climate change impacts will have consequences for the ability of human society to achieve sustainable development. SR15 concludes that “Limiting global warming to 1.5°C rather than 2°C would make it markedly easier to achieve many aspects of sustainable development, with greater potential to eradicate poverty and reduce inequalities ( ''medium evidence, high agreement'' )”. This assessment focuses on how climate change impacts on marine ecosystems would challenge sustainable development, using the United Nations SDGs as a framework to discuss the linkages between those issues.

Climate impacts on marine ecosystems affect their ability to provide seafood and raw materials, and to support biodiversity, habitats and other regulating processes (Section 5.4.1), and these impacts on the ocean affect people directly and indirectly (Sections 5.4.2.1, 5.4.2.2, 5.4.2.3). SDG 14 is the goal that is most directly relevant: “Life below water: including indicators for marine pollution, habitat restoration and protected areas, ocean acidification, fisheries, and coastal development.”

Climate impacts in the ocean to other SDGs are mediated through social and economic factors when the SDG targets are affected (Singh et al. 2019 <sup>[[#fn:r1605|1605]]</sup> ). For example, climate impacts on marine ecosystem services related to primary industries that provide food, income and livelihood to people have direct implications for a range of SDGs. These SDGs include ‘no poverty’ (SDG 1), ‘zero hunger’ (SDG 2), ‘decent work and economic growth’ (SDG 8), ‘reduced inequalities’ (SDG 10) and ‘responsible consumption and production’ (SGD 12) (Singh et al. 2019 <sup>[[#fn:r1606|1606]]</sup> , Figure 5.22). These impacts relate to changing ocean under climate change that affect the pathways to build sustainable economies and eliminate poverty (Sections 5.4.2.4), eliminate hunger and achieve food security (Section 5.4.2.1.3), reduce inequalities (Sections 5.4.2.2) and achieve responsible consumption and production (Sections 5.4.2.3.1) (Carvalho et al., 2017 <sup>[[#fn:r1607|1607]]</sup> ; Castells-Quintana et al., 2017 <sup>[[#fn:r1608|1608]]</sup> ). Climate change is also creating living conditions in coastal areas that are less suitable to human settlement and changing distributions of marine disease vectors (Section 5.4.2.1.1, 5.4.2.3.3), reducing our chances of achieving the goal for good health and well-being (SDG 3) (Pearse, 2017 <sup>[[#fn:r1609|1609]]</sup> ; Wouters et al., 2017 <sup>[[#fn:r1610|1610]]</sup> ). Women are often engaged in jobs and livelihood sources that are more exposed to climate change impacts from the ocean such as impacts on fisheries (Section 5.4.2.3.1) and impacts of SLR on coastal regions (Chapter 4). For example, in Senegal, women disproportionately engage in rice crop cultivation in coastal flood plain (Linares, 2009 <sup>[[#fn:r1611|1611]]</sup> ), and are thus exposed to the risks on their livelihood from rising sea levels and resulting salinisation (Dennis et al., 1995 <sup>[[#fn:r1612|1612]]</sup> ). Flooding in Bangladesh has increased the vulnerability of women to harassment and abuse as the flooding upends normal life and increases crime rates (Azad et al., 2013 <sup>[[#fn:r1613|1613]]</sup> ). As such, climate change may negatively affect our ability to achieve “gender equality” (SDG 5) (Salehyan, 2008 <sup>[[#fn:r1614|1614]]</sup> ). Impacts on living conditions as well as changing recreational, aesthetic, and spiritual experiences also affect our ability to achieve ‘sustainable cities and communities’ (SDG 11) (Section 5.4.2.2.1). The consequences of climate change in the ocean to achieving the remaining SDGs are less clear. However, the SDGs are interlinked, and achieving SDG 14, and especially the targets of increasing economic benefits to SIDS and Least Developed Countries, as well as eliminating illegal fishing and overfishing, will benefits all other SDGs (Singh et al., 2017 <sup>[[#fn:r1615|1615]]</sup> ). The interlinkages among SDGS mean climate change impact on the ocean will affect all other SDGs beside SDG14 in various ways, some possible direct and many indirect ( ''low confidence'' ).

Overall, climate change impacts on the ocean will negatively affect the chance of achieving the SDGs and sustaining their benefits ( ''medium confidence'' ).

<div id="section-5-4-2-5impacts-of-changing-ocean-on-sustainable-development-goals-block-2"></div>

<span id="figure-5.22"></span>
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'''Figure 5.22'''

<span id="figure-5.22-summary-of-the-types-of-relationships-negative-neutral-and-positive-between-impacted-marine-ecosystem-services-provisioning-regulating-supporting-and-cultural-and-the-sustainable-development-goals-sdgs-based-on-literature-review-and-expert-based-analysis-singh-et-al.-2019.-pie-charts-represent-the-proportion-of-targets-within-sdgs-that-a-particular-ocean-sdg-target"></span>
<!-- IMG CAPTION -->
'''Figure 5.22 | Summary of the types of relationships (negative, neutral and positive) between impacted marine ecosystem services (Provisioning, Regulating, Supporting and Cultural) and the Sustainable Development Goals (SDGs) based on literature review and expert-based analysis (Singh et al. 2019). Pie charts represent the proportion of targets within SDGs that a particular ocean SDG target […]'''
<!-- IMG FILE -->
[[File:ef37ea3803f5300e6161a04d4c4a1e99 IPCC-SROCC-CH_5_22.jpg]]

Figure 5.22 | Summary of the types of relationships (negative, neutral and positive) between impacted marine ecosystem services (Provisioning, Regulating, Supporting and Cultural) and the Sustainable Development Goals (SDGs) based on literature review and expert-based analysis (Singh et al. 2019). Pie charts represent the proportion of targets within SDGs that a particular ocean SDG target contributes to according to the literature reviewed and expert-based analysis presented in Singh et al. (2019).

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<span id="risk-reduction-responses-and-their-governance"></span>