1. Introduction
Currently, natural and human systems are experiencing the adverse effects of more than 1 °C of mean global warming compared to pre-industrial levels [
1,
2]. Therefore, there is a need for ecosystems and societies to adapt to the changing climate conditions. Policies and measures to adapt to and reduce climate-change-imposed risks are therefore being developed and implemented at different scales and in different settings across the globe [
3,
4,
5]. However, due to the inherent complexities of adaptation, it is not easy to assess whether the climate adaptation measures implemented are actually helping ecosystems and societies to adapt successfully. Context-specificity, meaning that what is identified as progress or successful adaptation by one community may not be recognized as such by another, is one of the key adaptation complexities involved [
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15].
Acknowledging such complexities, an important prerequisite to conducting a meaningful assessment of adaptation success is to have a sound understanding of what adaptation means. The IPCC’s Working Group II [
16] (p. 118) is the most commonly cited definition of climate adaptation:
“The process of adjustment to actual or expected climate and its effects. In human systems, adaptation seeks to moderate or avoid harm or exploit beneficial opportunities. In some natural systems, human intervention may facilitate adjustment to expected climate and its effects“. In the realm of successful adaptation an example is given by Doria et al. [
17] (p. 817):
“successful adaptation is any adjustment that reduces the risks associated with climate change, or vulnerability to climate change impacts, to a predetermined level, without compromising economic, social, and environmental sustainability”.Despite these and other academic efforts to define climate adaptation (e.g., [
16,
18]) and successful adaptation (e.g., [
5,
9,
17]), the literature still shows a limited understanding of both. For instance, scholars identify the IPCC’s definition of adaptation as being not “operational”, since it does not include specific elements that would allow measuring the progress obtained through adaptation measures [
17,
19,
20,
21]. Similarly, to the discussion on a standard definition for adaptation, the issue of successful adaptation has also been identified as an adaptation research priority [
13,
22,
23].
Current climate adaptation research is even more limited for the case of vulnerable regions in the Global South [
24,
25]. One of these regions is Latin America [
2,
24,
25,
26], which has been identified as “highly exposed, vulnerable and strongly impacted by climate change” [
25], with the level of implementation of adaptation lagging behind the actual needs [
25,
27,
28]. Equally, there are insufficient financial resources [
27,
28], as well as scarce information on the feasibility, and monitoring and evaluation (M&E) of adaptation options in the region [
25,
26,
29]. Overcoming these informational and financial limits is essential for the adequate funding and implementation of adaptation priorities [
30].
Moreover, it is crucial to note that the scope of the adaptation policies and monitoring and evaluation frameworks used in Latin America is limited to climate impact drivers, excluding social and economic aspects that influence the effectiveness of adaptation measures [
25,
31]. Among the barriers limiting adaptation policy monitoring and assessment in the region are the lack of a clear delimitation of adaptation policies, the lack of indicators to assess the effectiveness of adaptation measures, and the lack of mechanisms with which to track adaptation [
29].
The limitations on monitoring and evaluation in Latin America fall short of the ambitions for adaptation set at the global policy level. The global stocktake (GST) and global goal on adaptation (GGA) were established by the Paris Agreement within the United Nations Framework Convention on Climate Change (UNFCCC). The GST serves as the overarching mechanism with which to assess collective progress on mitigation, adaptation, and climate finance based on national reporting instruments. As part of the GST and in the realm of adaptation, the GGA includes a reduction in vulnerability, increase in resilience, and increase in adaptive capacities [
32].
However, most of the literature on the implementation and progress of adaptation is related to measures implemented at the local level. This and the circumstances of adaptation as they are at present, for example, in Latin America, present challenges at other levels of management in terms of data availability and comparable and meaningful indicators or proxies to measure adaptation, especially from the local to the global scale [
20].
The first GST is planned for 2023, and it will also review the overall progress made concerning the GGA [
32]. However, how can the impact of adaptation policies and interventions be measured or assessed if we do not have a common definition of adaptation or what successful adaptation entails? Moreover, how can we use information produced at local or subnational levels at the international (aggregated) level to inform the GST?
To contribute to the establishment of definitions of climate adaptation and successful adaptation, especially one that is applicable to different contexts and local specificities across the globe, it is pivotal that different perspectives be taken into account [
6]. Therefore, we investigated the views of Latin American experts on the definition of adaptation according to the IPCC [
16], as well as those on the definition of successful adaptation developed by Doria et al. [
17].
We used the Delphi method, a “group facilitation technique”, which utilizes an iterative, multistage process, to transform opinion into group consensus [
33] (p. 1008). The method has been used in a wide range of sectors and for multiple objectives, including for aspects relating to climate change adaptation (e.g., [
17,
34,
35,
36,
37,
38]). The method has already been applied by Doria et al. [
17] in their development of their own definition of successful adaptation. The Delphi method allowed us to identify the perspectives obtained from a heterogeneous panel of Latin American adaptation experts. The method facilitated a co-production process between the researchers and experts by identifying elements of agreement and disagreement. In this way, this method also facilitated the identification of ways to improve the existing definitions. Additionally, the method let us identify a list of criteria and indicators that could be used for aggregating information on adaptation from the local level to the global level to inform the GST.
With our work, we aim to provide guidance on (1) the aspects of definitions of adaptation and successful adaptation to foster their general operability and their use in adaptation success assessment, and (2) criteria and indicators that could support efforts to aggregate information on adaptation progress, for example, in the frame of the GST. To strengthen the respective research focusing on the Global South we apply our efforts to the case of Latin America.
2. Why Are Definitions for Climate Adaptation Important?
Definitions aim to establish and clarify what a word entails. They help to avoid ambivalences or ambiguities. Bassett and Folgemann [
39] (p. 51) highlight that “how we think and talk about adaptation matters in current and future debates on transformative climate action”. Until recently, adaptation to climate change was considered a nascent policy and research field [
40,
41,
42]. However, new literature shows that climate adaptation research is rapidly increasing in volume and diversifying [
24,
43,
44]. Moreover, following the establishment of the GST, research related to adaptation assessment has gained prominence.
Nevertheless, the definition of climate adaptation and, more importantly, what is considered successful adaptation, remains a challenge. Moreover, the usefulness of a definition of successful adaptation is being debated (e.g., [
14]). Questions remain about what it is necessary to evaluate (what is adaptation?) [
39,
45,
46,
47] and what we can classify as progress or success (what is successful adaptation?) [
9,
13,
30,
48,
49,
50].
Recent literature speaks of climate adaptation as a public good [
9], as a public goal [
51], and as an investment [
13]. Moreover, is seen as a process, an adjustment, or an outcome [
50,
52]. All those perspectives highlight the need to evaluate adaptation measures, especially in light of the limited financial resources available, the global policies in place, and the risk of maladaptation [
3,
30,
50,
53,
54]. The questions regarding the definition of adaptation and successful adaptation are relevant to all levels where the planning, design, and implementation of adaptation take place. However, there might be “no easy or political answers” [
9] (p.1), underpinning the need for a profound scientific understanding of what adaptation and its success entail.
As part of a wider debate, there are discussions on the need to differentiate adaptation from development [
19,
55,
56], as well as discussions about whether adaptation outcomes should be additional or complementary to those obtained from development interventions alone [
19,
54].
According to Moser and Boykoff [
9], investigating successful adaptation achieves the following goals: communication and public engagement, deliberate planning and decision-making, improved fit with other policy goals, justification of adaptation expenditures, improved accountability, and support for learning and adaptive management.
Regarding the assessment of adaptation measures and the aggregation of relevant information, the UNFCCC guides policies and actions undertaken at different management levels. In this regard, Magnan and Ribera [
45] (p. 1282) find it “crucial to overcome the intuitive and subjective understanding of adaptation”. The establishment of the GST as part of the Paris Agreement reflects and responds to the need for a better overview of how well or how successfully we adapt to climate change. However, how do we arrive at a reliable overview? Magnan [
57] indicates the need to develop metrics, which must comply with two characteristics: the consideration of context-dependent aspects (“national circumstances”) and allowing for the aggregation of information from the local through to the global level.
The UNFCCC already recognizes the multiple dimensions where adaptation actions or interventions take place [
32]. Despite this, much of the literature describes adaptation as a “local” issue [
44]. As a result, monitoring and evaluation (M&E) frameworks are mainly developed for use at the local level (e.g., for a community or project/program) [
58]. Likewise, the GST’s evaluation of adaptation progress is based on national assessments, and accordingly most efforts to inform the GST focus on the national level (e.g., [
59,
60,
61,
62,
63]). However, adaptation and reporting on adaptation progress also need to be considered as part of broader subnational, national, regional, and global mechanisms, such as the GST [
64] (see
Figure 1). Nevertheless, there are also limits to an aggregated view of adaptation, as not all metrics can be used at all levels [
19].
In addition to the disconnection between the levels where adaptation policies are developed and actions implemented, most M&E frameworks developed for adaptation focus on providing accountability. This approach aligns with the need to guarantee that the limited resources available for adaptation are invested efficiently [
65]. However, it does not provide guidance on, for example, the goals of vulnerability reduction or how to increase resilience [
54,
66]. Policymakers and practitioners face this type of challenge when evaluating and aggregating information on adaptation progress, together with those related to context, definitions chosen, and the availability of information [
49,
67,
68].
6. Conclusions
Global policy agendas might guide adaptation actions, but actions are implemented at the local level. Adaptation implementation and success depend on site-specific conditions. Therefore, before adaptation progress or success can be evaluated more consistently on such different levels, we need to know how climate adaptation is defined and what is considered progress and success. Additionally, there is a need to identify ways to support efforts to aggregate information on adaptation progress. However, this discussion is absent from the climate-related literature on Latin America. Therefore, we investigated the perspectives of Latin American experts on the aforementioned issues using the Delphi method. Our results confirm the complexity of the discourse on adaptation.
Overall, the Delphi method proved to be useful for the co-production of knowledge, facilitating the identification of different aspects that can serve as a basis for improving climate change adaptation monitoring and evaluation activities.
We found a consensus (>80%) with the IPCC’s definition of climate adaptation [
16] among the Latin American experts. In contrast, there was no consensus regarding the definition of successful adaptation developed by Doria et al. [
17]. The aspects with which most of the experts disagreed were the lack of elements to support evaluation efforts and the lack of recognition of the potential for transformation that adaptation can provide. Instead, the experts identified resilience and adaptive capacity as elements that could improve Doria et al.’s [
17] definition of successful adaptation.
Additionally, we presented a list of criteria and indicators of successful adaptation that could support evaluation and aggregation efforts. Such indicators have been identified as a knowledge gap in the Latin American region. Here, we observed that most of the criteria and indicators proposed by the experts were related to adaptive capacity, identified in the climate-related literature as a crucial component when implementing adaptation measures. Our results confirm that there is no one method or one approach for evaluating adaptation.
The criteria and indicators identified in this exercise can help in the investigation of successful adaptation characteristics applicable at different management levels while providing guidance for policy makers and practitioners ahead of the first global stocktake. While our results are limited to the identification of criteria and indicators, they could specifically contribute to a structured approach that captures aspects of representativeness and comparability, as suggested by Magnan and Ribera [
45]. For example, regarding the criteria and indicators identified for the adaptive capacity component of the GST, the elements of context and the factors that influence the performance of the adaptation measures could be investigated.
Additionally, future research efforts should focus on developing and characterizing the identified criteria and indicators for the different levels of management by identifying the kind of information needed at each level, how the information should be collected, and how it could be aggregated and integrated into the reporting tools. The Delphi method could also be applied to these objectives. Similar exercises could also be developed in other regions to identify, compare and analyze how the different perspectives, elements, criteria, and indicators identified depend on the geographical context.
In conclusion, we present the level of agreement of experts and ways to improve the definitions of climate adaptation and successful climate adaptation, as well as criteria and indicators that could help to aggregate adaptation information from the local to the global level. The outcomes, which present a regional perspective, can guide the Paris Agreement’s global stocktake and contribute to the debate on successful climate adaptation.