Editing IPCC:AR6/WGII/Chapter-18 (section)

==== 18.2.5.1 Adaptation ====

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===== 18.2.5.1.1 Adaptation and Climate Resilient Development =====

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Given that adaptation is recognised as a key element of addressing climate risk and CRD, the capacity for adaptation implementation is an important consideration for CRD. The AR5 noted a significant overlap between indicators of sustainable development and the determinants of adaptive capacity, and suggested that adaptation presents an opportunity to reduce stresses on development processes and the socio-ecological foundations upon which they depend ( [[#Denton--2014|Denton et al., 2014]] ). At the same time, it also noted that building adaptive capacity for sustainable development might require transformational changes that shift impacted systems to new patterns, dynamics or places ( [[#Denton--2014|Denton et al., 2014]] ). Thus, adaptation interventions and pathways can further the achievement of development goals such as food security ( [[#Campbell--2016|Campbell et al., 2016]] ; [[#Douxchamps--2016|Douxchamps et al., 2016]] ; [[#Richardson--2018|Richardson et al., 2018]] ; [[#Bezner%20Kerr--2019|Bezner Kerr et al., 2019]] ) and improvements in human health ( [[#Watts--2019|Watts et al., 2019]] ) including in systems where animals and humans live in close proximity ( ''very high confidence'' ) ( [[#Zinsstag--2018|Zinsstag et al., 2018]] ). However, to do so requires not only the avoidance of incremental adaptation actions that extend current unsustainable practices, but also the ability to manage and overcome the barriers which arise when the limits of incremental adaptation are reached ( ''high agreement'' , ''medium evidence'' ) ( [[#Few--2017|Few et al., 2017]] ; [[#Vermeulen--2018|Vermeulen et al., 2018]] ; [[#Fedele--2019|Fedele et al., 2019]] ).

Since AR5, the scientific community has deepened its understanding of the relationship between adaptation and sustainable development ( ''very high confidence'' ), particularly with regard to the place of resilience at the intersection of these two arenas. The literature has moved forward in its identification of specific overlaps in sustainable development indicators and determinants of adaptive capacity, how adaptation might reduce stress on development processes and their socio-ecological foundation, and how building adaptive capacity might facilitate needed transformative changes. Broadly speaking, work on these topics comes from one of two perspectives. One perspective speaks to adaptation practices that might further sustainable development outcomes, while another perspective draws on deeper understandings of the socio-ecological dynamics of the systems in which we live, and which we may have to transform in the face of climate change impacts. These two literatures are not yet well integrated, leaving gaps in our knowledge of how best to implement adaptation in a manner that achieves sustainable development.

The literature considering adaptation and development in practice since AR5 suggests that efforts to connect adaptation to sustainable development should address proximate and systemic drivers of vulnerability ( [[#Wise--2016|Wise et al., 2016]] ), while remaining flexible and reversable to avoid the lock-in of undesirable or maladaptive trajectories ( [[#Cannon--2010|Cannon and Müller-Mahn, 2010]] ; [[#Wise--2016|Wise et al., 2016]] ). Such goals require critical reflection on processes for decision making and learning. In the AR5, more inclusive, participatory adaptation processes were presumed to benefit development planning by including a wider set of actors in discussions of future goals ( [[#Denton--2014|Denton et al., 2014]] ). The post-AR5 literature expands on these critical perspectives to provide context regarding when participation is most effective. For example, ( [[#Eriksen--2015|Eriksen et al., 2015]] ) emphasise the need to build participatory adaptation processes to avoid subsuming adaptation goals to development-as-usual, while ( [[#Kim--2017b|Kim et al., 2017b]] ) argues that this practice is most effective when it is focused on development efforts and considers how climate change will challenge the goals of those efforts. Adaptation, while presenting an opportunity to foster transformations needed to address the impacts of climate change on human well-being, is also a contested process that is inherently political ( ''medium agreement'' , ''medium evidence'' ) ( [[#Eriksen--2015|Eriksen et al., 2015]] ; [[#Mikulewicz--2019|Mikulewicz, 2019]] ; Nightingale Böhler, 2019; [[#Eriksen--2021b|Eriksen et al., 2021b]] ). How adaptation can challenge development and create a situation where CRD effectively becomes transformative adaptation, adaptation that generates transformation of broader aspects of development, remains unclear ( ''medium agreement'' , ''limited evidence'' ) ( [[#Few--2017|Few et al., 2017]] ; [[#Schipper--2020c|Schipper et al., 2020c]] ).

The critical literature on socio-ecological resilience, which has grown substantially since the last AR ( ''very high confidence'' ), speaks to some of these questions. Since AR5, the IPCC and the wider literature on socio-ecological resilience have shifted their use of the term to reflect not only the capacity to cope with a hazardous event or trend or disturbance, but also the ability to adapt, learn and transform in ways that maintains socio-ecology’s essential function, identity and structure (Chapter 1; Glossary, Annex II). This change in usage is significant in that it shifts resilience from an emergent property of complex socio-ecological systems to a deeply human product of efforts to manage ecology, economy and society to specific ends. This definition of resilience recognises the need to define what is an essential identity, function and structure for a given system, questions rooted not in ecological dynamics, but in politics, agency, difference and power that emerge around the management of ecological dynamics ( [[#Cote--2011|Cote and Nightingale, 2011]] ; [[#Brown--2013|Brown, 2013]] ; [[#Cretney--2014|Cretney, 2014]] ; [[#Forsyth--2018|Forsyth, 2018]] ; [[#Matin--2018|Matin et al., 2018]] ; [[#Carr--2019|Carr, 2019]] ).

By connecting this framing of socio-ecological dynamics to the literature on the principles for adaptation efforts that meet development goals, new work has begun to identify 1) how adaptation can reduce stress on development processes, 2) how it might facilitate transformative change and 3) where adaptation interventions might either drive system rigidity and precarity, or otherwise challenge development goals ( [[#Castells-Quintana--2018|Castells-Quintana et al., 2018]] ; [[#Carr--2020|Carr, 2020]] ). For example, [[#Jordan--2019|Jordan (2019)]] draws upon these contemporary framings of resilience to highlight the ways in which coping strategies perpetuate the gendered norms and practices at the heart of women’s vulnerability in Bangladesh. [[#Forsyth--2018|Forsyth (2018)]] draws upon this work to highlight the ways in which the theory of change processes used by development organisations tend to exclude local experiences and sources of risk, and thus foreclose the need for transformative pathways to achieve development goals. Carr ( [[#Carr--2019|Carr, 2019]] ; 2020) draws upon evidence from sub-Saharan Africa to develop more nuanced understandings of the ways in which different stressors and interventions either facilitate or foreclose transformative pathways, while pointing to the existence of yet poorly understood thresholds for transformation in systems that can be identified and targeted by interventions.

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===== 18.2.5.1.2 Adaptation gaps =====

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Adaptation gaps are defined as ‘the difference between actually implemented adaptation and a societally set goal, determined largely by preferences related to tolerated climate change impacts and reflecting resource limitations and competing priorities’ ( [[#UNEP--2014|UNEP, 2014]] ; [[#UNEP--2018a|UNEP, 2018a]] ). Adaptation deficit is a similar concept, described as an inadequate or insufficient adaptation to current conditions (Chapter 1). Adaptation gaps or deficits arise from a lack of adequate technological, financial, social, and institutional capacities to adapt effectively to climate change and extreme weather events, which are in turn linked to development ( ''very high confidence'' ) ( [[#Fankhauser--2014|Fankhauser and McDermott, 2014]] ; [[#Milman--2014|Milman and Arsano, 2014]] ; [[#Chen--2016|Chen et al., 2016]] ; [[#Asfaw--2018|Asfaw et al., 2018]] ) ( [[#18.2.2|Section 18.2.2]] ).

Currently, there is no consensus around approaches to assess the effectiveness of adaptation actions across contexts and therefore measure adaptation gaps at a global scale ( [[#Singh--2021a|Singh et al., 2021a]] ). [[#UNEP--2021|UNEP (2021)]] suggests that comprehensiveness, inclusiveness, implementability, integration and monitoring, and evaluation can be used to assess them (see also Cross-Chapter Box FEASIB). However, limited information is available about future trends in national-level adaptation and the development of monitoring and evaluation mechanisms. Despite the challenges of measurement associated with adaptation gaps, available evidence from smaller scales across several regions, communities and businesses suggest that significant adaptation gaps have existed in historical contexts of climate change, while expectations of extreme heat, increasing storm intensity and rising sea levels will create the context for the emergence of new gaps ( ''very high confidence'' ) ( [[#Hallegatte--2018|Hallegatte et al., 2018]] ; [[#UNEP--2018a|UNEP, 2018a]] ; [[#Dellink--2019|Dellink et al., 2019]] ; [[#UNEP--2021|UNEP, 2021]] ). These adaptation gaps create risks to well-being, economic growth, equity, the health of natural systems and other societal goals. The negative impacts of these gaps can be compounded by adaptation efforts that are considered maladaptive or by development actions that are labelled as adaptation (see Chapter 16).

A higher level of adaptation finance is critical to enhance adaptation planning and implementation and reduce adaptation gaps, particularly in developing countries ( ''very high confidence'' ) ( [[#UNEP--2021|UNEP, 2021]] ) (Cross-Chapter Box FINANCE in Chapter 17, [[#18.4.2.2|Section 18.4.2.2]] ). However, adaptation finance is not keeping pace with the rising adaptation costs in the context of increasing and accelerating climate change, as ‘annual adaptation costs in developing countries alone are currently estimated to be in the range of US$70 billion, with the expectation of reaching US$140–300 billion in 2030 and US$280–500 billion in 2050’ ( [[#UNEP--2021|UNEP, 2021]] ). Investment in attaining SDGs helps bridge adaptation gaps ( [[#Birkmann--2021|Birkmann et al., 2021]] ), but care needs to be taken to avoid maladaptation through mislabelling. Integration of the Indigenous and local knowledge systems is anticipated to reduce existing adaptation gaps and secure livelihood transitions.

Analysis of investments by four major climate and development funds (the Global Environment Facility, the Green Climate Fund, the Adaptation Fund and the International Climate Initiative) by [[#UNEP--2021|UNEP (2021)]] suggests that support for green and hybrid adaptation solutions has been increasing over the past two decades. These could be effective at reducing climate risks and bridging adaptation gaps while simultaneously bringing important additional benefits for the economy, environment and livelihoods ( [[#UNEP--2021|UNEP, 2021]] ) (see also Cross-Chapter Box NATURAL in Chapter 2).

Lately, the evidence of adaptation activity in the health sector has been increasing ( [[#Watts--2019|Watts et al., 2019]] ), yet substantial adaptation gaps persist ( [[#UNEP--2018a|UNEP, 2018a]] ; [[#UNEP--2021|UNEP, 2021]] ), including gaps in humanitarian response to climate-related disasters ( [[#Watts--2019|Watts et al., 2019]] ). It is the under-investment in climate and health research in general and health adaptation in particular that has led to adaptation gaps in the health sector ( [[#Ebi--2017|Ebi et al., 2017]] ).

Costs of implementing efficient adaptation measures and water-related infrastructure in water-deficient regions have received attention at the global and regional level to bridge the ‘adaptation gap’ ( [[#Hallegatte--2018|Hallegatte et al., 2018]] ; [[#UNEP--2018a|UNEP, 2018a]] ; [[#Dellink--2019|Dellink et al., 2019]] ; [[#UNEP--2021|UNEP, 2021]] ). Livelihood sustainability in the drylands, which cover more than 40% of the land surface area, are home to roughly 2.5 billion people, and support approximately 50% of the livestock and 45% of the food production, is threatened by a complex and inter-related range of social, economic and environmental changes that present significant challenges to rural communities, especially women ( [[#Abu-Rabia-Queder--2018|Abu-Rabia-Queder and Morris, 2018]] ; [[#Gaur--2018|Gaur and Squires, 2018]] ). Adaptation deficits in arid and semi-arid regions are of high order (see CROSS-CHAPTER BOX 3). To reduce adaptation deficit in arid and semi-arid regions, comprehensive and efficient adaptation interventions integrating better water management, use of non-traditional water sources, changes in reservoir operations, soil ecosystem rejuvenation and enhanced institutional effectiveness are needed ( [[#18.5|Section 18.5]] ) ( [[#Makuvaro--2017|Makuvaro et al., 2017]] ; [[#Mohammed--2017|Mohammed and Scholz, 2017]] ; [[#Morote--2019|Morote et al., 2019]] ). Communities facing the lack of adequate technological, financial, human and institutional capacities to adapt effectively to current and future climate change often encounter adaptation deficits. To address current adaptation barriers and adaptation deficits, there is a need to promote efficient adaptation measures, coupled with inclusive and adaptive governance involving marginalised groups such as Indigenous communities and women.

Although unevenly distributed urban adaptation gaps exist in all world regions (see Chapter 6). Such gaps are higher in the urban centres of the poorer nations. [[IPCC:Wg2:Chapter:Chapter-6|Chapter 6]] identified that the critical capacity gaps at city and community levels responsible for adaptation gaps are the ‘ability to identify social vulnerability and community strengths, and to plan in integrated ways to protect communities, alongside the ability to access innovative funding arrangements and manage finance and commercial insurance; and locally accountable decision making with sufficient access to science, technology and local knowledge to support the application of adaptation solutions at scale’.

Insufficient financial resources are the main reasons for the coastal adaptation gap, particularly in the Global South (see CROSS-CHAPTER BOX 2). Engaging the private sector with a range of financial tools is crucial to address such gaps (see CROSS-CHAPTER BOX 2). An urgent and transformative action to institutionalise locally relevant integrative adaptation pathways is crucial for closing coastal adaptation gaps. Additional efforts are in place for assessing global adaptation progress (see Cross-Chapter Box PROGRESS in Chapter 17).

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===== 18.2.5.1.3 Adaptation implementation =====

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As discussed in Chapter 16, adaptation is a key mechanism for managing climate risks, and therefore for pursuing CRD. The lower estimates in Table 18.2 are associated with higher levels of adaptation and more conducive development conditions. Furthermore, additional adaptation demand is associated with greater levels of climate change. Adaptation is a broad term referring to many different levels of response and options for natural and human systems, from individuals, specific locations and specific technologies, to nations, markets, global dynamics and strategies at the system level. Adaptation also includes endogenous reflexive and exogenous policy responses. Perspectives on limits to adaptation, synergies, trade-offs and feasibility therefore depend on where the boundaries are drawn and the objective. Overall, there are a broad range of adaptation options relevant to reducing risks posed by climate change to development. However, current understanding of how such options are implemented in practice, their effectiveness across a range of possible climate futures and their potential limits, is modest.

The IPCC’s SR1.5 report evaluated individual adaptation options in terms of economic, technological, institutional, socio-cultural, environmental/ecological and geophysical feasibility ( [[#de%20Coninck--2018|de Coninck et al., 2018]] ). This analysis has been updated for AR6 (Cross-Chapter Box FEASIB). These assessments identify types of barriers that could affect an option’s feasibility. Among other things, this work finds that every adaptation option evaluated had at least one feasibility dimension that represented a barrier or obstacle. The barriers also imply that there are trade-offs in these feasibility dimensions to consider. Overall, insights from this work are high-level and difficult to apply to a specific adaptation context. The feasibility and ranking of adaptation opportunities, as well as the list of opportunities themselves, for a given location will vary from location to location, with different criteria and weighting of criteria that reflect the priorities of society and decision-makers as well as differences in markets, technology options and policies for managing risks and trade-offs. Integrated evaluation of criteria and options is needed, that accounts for the relevant geographic context and interactions between options and systems ( [[#18.5|Section 18.5]] ).

Sustainable development is regarded as generally consistent with climate change adaptation, helping build adaptive capacity by addressing poverty and inequalities and improving inclusion and institutions ( [[#Roy--2018|Roy et al., 2018]] ). Some sustainable development strategies could facilitate adaptation effectiveness by addressing wider socioeconomic barriers, addressing social inequalities and promoting livelihood security ( [[#Roy--2018|Roy et al., 2018]] ). With a common goal of reducing risks, sustainable development and adaptation are relatively synergistic. For example, “low-regrets” adaptation strategies have been identified, such as improvements in health systems that reduce climate health impacts in cities (Barata, 2018). However, trade-offs also have been found and are important to consider and potentially address. Synergies have been found between adaptation and poverty reduction, hunger reduction, clean water access and health; while, trade-offs have also been found, particularly when adaptation strategies prioritise one development objective (e.g., food security or heat-stress risk reduction) or promote high-cost solutions with budget allocation and equity implications ( [[#Roy--2018|Roy et al., 2018]] ) (Sections 18.2.5.3, 18.5, Box 18.4). There are also opportunities for addressing the trade-offs, in particular distributional effects—by recognising that there are trade-offs and considering alternatives and complementary strategies to address those trade-offs ( [[#18.2.5.3|Section 18.2.5.3]] ).

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