Our results reveal that there has been a rapidly growing interest in studying adaptation mainstreaming over the past decade (see Annex 3), which also might indicate an increase in actual cases of mainstreaming practices.
Mainstreaming definitions and interpretations
Regarding the different definitions and interpretations of mainstreaming used, we find that 70% of the reviewed papers provide an explicit definition of adaptation mainstreaming (see Annex 4 for an overview of definitions). However, in only 40% of the papers an explicit framework for analysing or operationalising mainstreaming is applied. Some papers have adopted the use of key criteria for integrated policies proposed by Mickwitz et al. (2009). In other papers, mainstreaming is analysed in terms of different mainstreaming strategies similar to those proposed by Wamsler and Pauleit (2016). The fact that 60% of the papers did not employ an explicit framework for analysing or operationalising mainstreaming suggests that there is ample scope for more specific definitions and explicit operationalisations as well as more unified operationalisation in order to facilitate comparative analysis, policy recommendations and learning.
In just more than half of the papers, mainstreaming is explicitly distinguished from a dedicated adaptation approach. Twelve papers that made such explicit distinction (14% of all papers) report on experiences with both approaches to climate adaptation. For instance, Stiller and Meijerink (2016) and Wamsler (2015) describe the employment of climate adaptation officers via climate-related funding (dedicated approach) to facilitate the integration of climate adaptation as a central theme in sector development planning and work streams of sub-regional, local administrations (mainstreaming) in Germany. Another example of such a mixed, or nested, approach are national or municipal adaptation plans (representing a dedicated approach) that include provisions to mainstream climate adaptation objectives into sectoral policies and plans, as outlined by Biesbroek et al. (2010), Saito (2013) and Wamsler (2015). Again, these results show the importance of more precise and consistent terminology to facilitate comparative analysis, policy recommendations and learning.
What is mainstreamed into what?
Looking at the policy level of mainstreaming practices studied, our results show that adaptation mainstreaming has mainly taken place at national government level (39%) and local government level (35%). The national level thus gets the most attention, despite the fact that municipalities or cities are increasingly seen as the key stakeholders in adaptation planning (Bulkeley and Betsill 2013). In terms of substantive focus, in the reviewed cases the climate risks in focus are flooding, changing temperatures, and extreme heat and cold. However, there is quite an even spread among these three and other categories (e.g. extreme weather events in general, drought and water scarcity, sea level rise and erosion), meaning that there is no clear pattern. Finally, in terms of policy sectors in which adaptation objectives are mainstreamed, the most dominant ones are environmental and natural resources management (including agriculture, coastal zone management, environmental management, nature and biodiversity conservation and green infrastructure), followed by urban/regional (land use) planning, water/flood risk management, and crisis management and risk reduction planning (Fig. 2). In contrast, there are fewer reports of climate adaptation mainstreaming in critical infrastructures such as water supply and sanitation, housing, transportation and telecommunications, despite their widely-recognised importance (Runhaar et al. 2016; IPCC 2014). Surprisingly, housing, transport and telecommunications are relatively less subject to mainstreaming than other policy sectors. Yet, with their typically long planning and investment horizons (meaning that climate proofing is particularly critical), housing, transport and telecommunications are sectors that merit more attention for adaptation mainstreaming.
Mainstreaming strategies
During the coding of the papers it appeared that the strategy of “programmatic mainstreaming” posed problems because it was difficult to distinguish this strategy from its achievements in terms of policy outputs and outcomes. Therefore it was ignored in the analysis. Considering the remaining strategies, our results show that regulatory mainstreaming (which ranges from including climate adaptation as an objective in sectoral policy documents to changes in strategic planning and legislative tools), is the most frequently reported strategy (86% of cases). The relatively lower frequency of managerial (73%) and intra- and inter-organisational (54%) mainstreaming suggests that more practical approaches are still lacking, i.e. how to achieve a stated policy aspiration or requirement in practice. In addition, directed mainstreaming (that is, higher level support to redirect the focus to aspects related to mainstreaming adaptation by e.g., providing topic-specific funding, promoting new projects, supporting staff education, or directing responsibilities) is least reported (37%). This suggests that mainstreaming is often a rather informal activity that is pushed by local needs and bottom-up processes rather than pushed by higher level authorities (cf. Wamsler 2015). Looking at the adoption of mainstreaming strategies over time, they follow a similar curve (peaking in 2010, but likely due to the time period selected for inclusion of papers) which suggests that relative preferences have not changed over time.
Mainstreaming effectiveness—outputs and outcomes
In most of the cases (98%), it was reported that mainstreaming had led to policy outputs, whereas policy outcomes were reported in only half of the cases (51%). Scoring the outputs and outcomes in terms of whether they were seen by the authors to represent effective, partly effective or ineffective mainstreaming, the results clearly show that mainstreaming has been more successful in producing effective policy outputs than effective outcomes (Fig. 3). This means that the literature finds adaptation mainstreaming more effectively addressed in sector policy documents and plans, than in concrete projects and activities. In other words, there seems to be an implementation gap in translating mainstreamed sectoral policies into concrete adaptation on the ground.
Further, qualitative assessment of the identified outputs and outcomes suggests that effective outputs were mainly reported when several mainstreaming strategies were employed simultaneously and when higher-level changes were operationalised at local level, for instance, into the set-up of functional, supportive municipal structures, enshrining climate adaptation in local programming, enhanced coordination and collaboration of stakeholders, or the renegotiation of responsibilities (Stiller and Meijerink 2016). Unfortunately, the number of papers in which single strategies were reported was too small for an analysis of relative effectiveness of mainstreaming strategies.
Zooming in on the most prominent policy sectors (n > 20) we found that not only the number of strategies employed but also their composition are decisive factors for effective mainstreaming (measured in terms of policy outputs), irrespective of the sector (see Annex 5). The majority of success cases across all four sectors exhibits a combination of managerial, intra- and inter-organisational, and regulatory mainstreaming (90% in environmental and natural resources management, 82% in crisis management, 74% in urban planning, and 65% in water and flood risk management). Directed mainstreaming would seem a powerful strategy to promote climate adaptation mainstreaming, but is less prevalent in cases with effective policy outputs, which can be explained by our finding that it is the least observed strategy. Possibly absence of directed mainstreaming can be compensated by employing multiple other strategies.
A comparison of whether mainstreaming has been effective or partly effective at the policy output level across our three country groupings shows that Europe has the largest share in effective outputs (70%, compared with 52% of all outputs observations) (Fig. 3). Developing countries show the largest share of partly effective mainstreaming outputs, which suggests that robust mainstreaming strategies are yet to mature and that developing countries have comparatively greater difficulties to sustain adaptation practices.
The situation is quite different, and the picture more unified, when we compare policy outcomes across country groups. In fact, effective outcomes are low in numbers across all country groups. The relatively high frequency of partly effective outcomes across all country groups (developed or developing) suggests that crossing the threshold between pilot projects and institutionalisation of practices is difficult, no matter what region or context.
Mainstreaming drivers and barriers
What explains these mainstreaming achievements and ‘what works’? Our literature review looked at drivers and barriers mentioned in the analysed cases that report on both outputs and outcomes, in a similar way as Biesbroek et al. (2013) did for adaptation in general. Our analytical framework (see “Analytical framework” section) includes 32 factors that can promote or inhibit mainstreaming, grouped in six categories (see “Analytical framework” section).
Our results show that the most often mentioned drivers are, in order: political commitment; cooperation with private actors; the presence of policy entrepreneurs; focusing events; and lastly subsidies from higher levels of government which is on par with framing and linking to sectoral objectives (see Table 1). While the importance of political commitment and external cooperation is thus recognised, it is not reflected in practice (with directed and inter-organisational mainstreaming being the least reported strategies). While the mentioned drivers are also found in much literature on general EPI, the role of (a) cooperation with private actors and (b) focusing events appears to be more crucial in this specific context of climate adaptation mainstreaming. The importance of the latter stems from the perceived urgency and enhanced public and stakeholder support for adaptation action after climate events (“focusing event”), although we expect this so-called window of opportunity to be generally very short-lived.
Table 1 Frequency of drivers and barriers reported in cases with outputs and outcomes
The most frequently reported barriers are lack of: financial resources, information, guidance, coordination and cooperation between departments, staff resources and access to adaptation knowledge and expertise as well as conflicting interests. Note that some factors (e.g. coordination/cooperation between government departments, and information and guidance) are almost as often reported to be drivers as barriers, which suggests they are particularly important to get right. The importance of good coordination and cooperation between government departments contrasts with the identified mainstreaming strategies, in that intra-organisational mainstreaming was not reported as a common strategy while forming an integrative part of success cases (see above). Also for the cases scored as yielding effective policy outputs (n = 50) a pattern emerges, which is similar to this picture. In sum, while the identified drivers and barriers match the key attributes of the different mainstreaming strategies (see “Analytical framework” section), and in turn support the identified importance of employing multiple strategies for effective outputs (see above), current practice is lagging behind.
Learning from mainstreaming failure
An analysis of “what works” is incomplete without learning from the cases where mainstreaming has failed. Therefore, we take a closer look at prominent barriers reported in those cases where outputs did not translate into implementation of adaptation measures. These may provide explanations why ensuring outcomes from mainstreaming strategies are experienced as a challenge, which applies across all country groups. We decided against further comparing these cases with the ones that reported on ineffective outcomes, since the sample was too small to be conclusive.
As could be expected from their relative importance in the successful cases, the most frequently mentioned barriers for cases where outputs did not translate into implementation are: a lack of coordination and cooperation between departments within and across policy domains, closely followed by a lack of financial resources (see Annex 6). These further support above-mentioned explanations for directed and inter-organisational mainstreaming being the least reported strategies and underline their importance for both outputs and outcomes. Additional factors scoring high as barriers are: the absence of clear mandates, conflicting political interests, and organisational structures, routines, and practices. Overall, most of the dominant barriers to implementation are found in organisational factors (linked to managerial and inter-organisational mainstreaming) and, to a lesser extent, in the resources and cognitive categories. In contrast, factors that we classified within the timing and political categories (except for conflicting interests) seem to play a subordinate role as these were least often mentioned. Furthermore, access to expertise and information and guidance are not among the prominent barriers. This suggests that the implementation gap is not primarily an issue of lack of knowledge or financial resources, but first of all needs to be addressed by reviewing inner-organisational structures, practices and ways of collaboration both internally and externally. In other words, practitioners do seem to have the knowledge about potential adaptation measures but are experiencing trouble putting them into practice within existing structures.