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

===== 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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