1. Introduction
Due to the current state of global warming, it is critical, and more important than ever, to take steps to reduce the rate of climate change in order to secure a “safe operating space for humanity” [
1]. In Europe, the fifth IPCC Assessment Report indicates a temperature increase throughout all climate regions of Europe if the current warming rate continues [
2], likely reaching a 1.5 °C increase compared to pre-industrial levels between 2030 and 2052 [
3]. To make projections on anthropogenic greenhouse gas (GHG) emissions, the IPCC adopted four Representative Concentration Pathways (RCPs), which describe different emission scenarios for the 21st century. RCP2.6 outlines a stringent mitigation pathway, requiring GHG emissions to start declining by 2020 [
4]. RCP4.5 and RCP6 represent two intermediate pathways, and RCP8.5, the most pessimistic scenario, represents the worst-case climate change scenario, including very high GHG emissions [
5]. Depending on the scenario, the global mean temperature will rise by at least 0.3 °C (RCP2.6) to 4.8 °C (RCP8.5) by the end of the 21st century due to increasing GHG emissions [
4]. Projections show significant increases in high-temperature extremes and the frequency and intensity of heat waves, drought periods, and heavy precipitation events, subjecting water management to a broad range of changes [
6].
New approaches for sustainable development in consonance with planetary boundaries are urgently needed [
7]. In this context, biosphere-based sustainability science has emerged as a new research field, providing new analytical concepts, such as the social–ecological systems (SES) framework [
8]. The SES approach has evolved into an eminent analytical frame to address pressing questions of future development, resilience, and long-term sustainability [
9].
To protect and manage European water resources, EU policy has established the Directive 2000/60/EC, the European Water Framework Directive (WFD), in 2000 [
10]. It aims to reconcile the national water policies of EU Member States and establish a coherent legal framework at a European level [
11]. River Basin Districts (RBD) following natural geographical river basins and related River Basin Management Plans (RBMP) were drawn up to effectively meet water management needs at smaller scales [
12]. The WFD is regarded as the most ambitious and significant piece of European environmental legislation [
13]. It requires promoting sustainable water use, minimising pressures on water bodies, preventing further pollution, and mitigating floods and droughts [
10]. A WFD Fitness Check Evaluation, carried out in 2019, highlights that the directive has successfully prevented water body deterioration but has not fully achieved its ecological and chemical objectives [
12]. Assuming that water use and protection conflicts originate from natural or technical obstacles and have political, social, and cultural dimensions, the integrated water resources management paradigm is thus firmly established in the WFD [
14,
15]. The river basin approach, which allows comprehensive and transboundary water management at the river basin level, was a new concept introduced into EU policy [
12]. As RBDs are responsible for implementing the WFD, significant differences concerning the application of integrated water resources management still exist.
When the WFD was adopted and entered into force in 2000, global warming and its consequences had not been put on the main agenda as potential threats to European water bodies—this highlights the missing awareness of climate-change-related threats at the end of the 1990s [
12,
16]. In context of the WFD Common Implementation Strategy (CIS), Guidance Document No. 24 “River Basin Management in a Changing Climate” was published in 2009. The intention behind the document was to guide the EU Member States in integrating global warming and climate variability into water policy [
17]. Since the second river basin management cycle started in 2015, European Member States agreed that “climate-related threats and adaptation planning should be incorporated in their RBMPs” [
18] (p. 271). Although only a recommendation, this indicates a shift in problem awareness, showing that global warming threats have gained more attention in recent years [
12]. To quantify and visualise global warming-induced changes, especially on a smaller scale, regional climate models and sets of climate models are increasingly being used [
19,
20]. Due to their high resolution, regional climate models can capture complex physiographical features and spatial variability [
19]. Although uncertainties regarding the prediction accuracy still exist, for example, concerning the ability to represent the temporal variability of precipitation time series [
21], regional climate models represent an efficient tool to conduct hydrological analyses on a river basin scale, such as future precipitation, runoff scenarios, or flood risk assessments [
19,
20]. According to the WFD Fitness Check Evaluation, the WFD generally contributes to managing global warming challenges in the EU by restoring water bodies, regularly reviewing measures and progress, and implementing natural retention measures [
12]. Although the WFD is considered legally able to deal with emerging issues such as climate change due to its flexible nature, the WFD Fitness Check states that this is not sufficient for counteracting the effects in total [
12]. In the evaluation report, the authors argue that concerns about global warming do not necessarily result in practical action, and mitigation and adaptation planning are not yet covered in a completely integrated way. Furthermore, the authors state that the reference conditions of the WFD do not sufficiently consider global warming effects, as they are not explicitly mentioned as a threat or defined as an objective. Additionally, water scarcity remains poorly covered, as indirect measures are often ineffective, and monitoring is considered insufficient [
12]. Regarding coherence, the WFD Fitness Check concludes that stakeholders see climate change as the least-coherent subject within WFD legislation [
12]. Although most Member States have successfully carried out a “climate-proofing” of the Programme of Measures by applying the CIS Guidance Document No. 24, climate change adaptation cannot be fully pursued due to a failure to integrate global warming effects into WFD evaluations [
12]. According to the European Overview of River Basin Management Plans, most RBDs consider flood risk management, assess direct and indirect climate pressures, and address drought management and water scarcity [
18]. Nevertheless, drought management plans do not always correspond to the actual drought risk faced in practice [
18]. In summary, the report positively evaluates the WFD’s high flexibility in combatting global warming effects. Nonetheless, it cannot address climate change sufficiently, especially when it comes to practical action, coherence with other objectives, and drought management [
18].
The aim of this review study was to assess the effectiveness of global warming management within the WFD. To this end, we applied the SES approach to the Elbe RBD following the conceptual “typology of six organising principles” by Preiser et al. [
22]. We applied six distinctive SES features to this study: 1. “scale and openness”; 2. “context dependency”; 3. “self-organisation and adaptability”; 4. “non-linearity, uncertainty, unpredictability”; 5. “dynamics”; and 6. “constituted relationally”. To evaluate the extent to which each SES feature is considered in the water management of the Elbe River basin, we will address the following research question: With regard to global warming, to what extent does water management in the Elbe River Basin District take features of social–ecological systems into consideration?
2. Theoretical Framework
Social–ecological researchers investigate the dynamic interactions between humans and the environment using both social and natural sciences and are interested in the interface between science, politics, the economy, and the public [
23]. As human activity is an increasing pressure on ecosystems and has major impacts on their functioning, a clear distinction between social and natural systems is arbitrary [
24]. The SES approach emphasises this intertwined character and supports that environmental preconditions shape social dimensions (economy, politics, technology, culture, etc.). Vice versa, natural systems (terrestrial and aquatic ecosystems) are impacted by human activities [
8]; therefore, mutual interaction on different spatial and temporal scales is the consequence (
Figure 1) [
25]
.The SES approach evolved from biosphere-based sustainability science, which marks the stability and resilience of the biosphere as a crucial precondition for human wellbeing [
8]. The SES approach emerged as a prominent “conceptual and analytical framing with which to understand the connections and feedbacks between social and environmental interactions” [
9] (p. 1). It emphasises human dependency on ecosystems, supports cross-disciplinary collaboration, and allows researchers to understand systems [
7,
26]. Finally, increased system knowledge contributes to an acceptable way of managing resources towards resilience and long-term sustainability [
27].
Our study orientates at the “typology of six organising principles” accounting for key features of SES, according to the heuristic SES framework established by Preiser et al. [
22]. To apply this conceptual typology to the Elbe River basin case study, we adjusted and harmonised the types, or the name of the types, for our research purposes; however, the overall structure is preserved. As such, the six relevant characteristic features of SES for this study are 1. “scale and openness”; 2. “context dependency”; 3. “self-organisation and adaptability”; 4. “non-linearity, uncertainty, unpredictability”; 5. “dynamics”; and 6. “constituted relationally”. Properties and requirements associated with specific features are explained in detail in
Section 5, at the beginning of each feature’s section.
3. Methodological Approach
We reviewed key publications to determine how the WFD in general, and the Elbe RBD in particular, address global warming. We focused on publications of the European Commission and the Elbe River Basin Cooperation, including the WFD [
10], the Overview on River Basin Management Plans [
18], the WFD Fitness Check Evaluation [
12], the River Basin Management Plan for the German part of the river basin [
28], the German Programme of Measures [
29], and the German background document on climate change effects [
30]. Finally, we considered the International River Basin Management Plan for the Elbe RBD [
31].
In order to gain further insights into the interface between SES theory and WFD in the context of global warming, we conducted four guided expert interviews [
32,
33,
34,
35]. Bernd Klauer is deputy head of the Department of Economics at the Helmholtz-Centre for Environmental Research (UFZ, Leipzig, Germany). For many years he has been engaged in social–ecological approaches in environmental and resource economics concerning sustainability and the valuation of nature [
36,
37,
38]. Moritz Reese is deputy head of the Department of Environmental and Planning Law at the Helmholtz-Centre for Environmental Research (UFZ, Leipzig, Germany). His research focuses on European environmental law, water law, and climate change and adaptation [
16,
37,
39,
40,
41]. Laura Herzog is a political scientist working at the Institute of Environmental Systems Research at Osnabrück University. She works on the dynamics of SES and the influence of climate change and land use on aquatic ecosystem services [
42,
43]. Finally, Christine Wolf is a former member of the Department of Economics and the Department of Environmental Politics at the Helmholtz-Centre for Environmental Research (UFZ, Leipzig, Germany). In her doctoral thesis, she analysed water bodies as SES, integrating the effects of global warming to improve the methods used to evaluate the ecological status of water bodies [
44,
45,
46,
47,
48]. The interviews were conducted via video call and were recorded and transcribed afterwards (clean verbatim).
To evaluate SES features in Elbe River basin management, we conducted a semi-quantitative assessment for each feature in table form; therefore, we applied a rating scale of 1–5 with a score of 5 indicating full consideration of feature properties, and a score of 1 displaying very limited consideration. We derived the feature properties in the table from Preiser et al. [
22], De Vos et al. [
9], Berkes et al. [
7], and the expert interviews conducted [
32,
33,
34,
35].
4. The Elbe River Basin District
Since practical management of global warming impacts occurs in RBDs, the analysis of SES features must also occur in RBDs; therefore, we selected one RBD to assess the features. The choice fell on the Elbe RBD, because it is one of the largest European river basins crossing national borders and representing a transport route of significant international importance. Moreover, the effects of global warming are diverse due to the significant variability between areas along the river’s course, including sub-basins with high flood risk and sub-basins with low annual precipitation, potentially facing enhanced drought risk (
Figure 2).
Furthermore, the GLOWA Elbe research project, which started in 2000, investigated global change effects on the environment and society in the Elbe RBD [
32]. Due to the long project duration, and the “pioneering” character concerning global change impacts, the Elbe River basin features a significant projection and modelling database—this provides a favourable starting point for us to assess SES features in the Elbe RBD.
The Elbe is located 1386 m above sea level, rises in the Krkonoše mountains (Czech Republic), and flows for 1094 km, near Cuxhaven (Germany) into the North Sea (
Figure 2). The Elbe River basin is part of the temperate climate (Koeppen: Cfb). It is located in the transition zone from the humid oceanic climate of Western Europe and the dry continental climate of Central and Eastern Europe [
28]. The river has peak discharges in spring. Furthermore, heavy summer precipitation events can pose a major flood risk, as observed during the Elbe floods of 2002 and 2013 [
28]. The river basin covers 148,000 km
2, where 65.54% is located in Germany, 33.68% in the Czech Republic, and two smaller shares are located in Austria (0.62%) and Poland (0.16%). About 25 million people live in the Elbe RBD [
31].
In the Elbe River basin, the effects of global warming will be marked by an increase in annual mean air temperature, more frequent and intensified extreme weather events, and changes in seasonal precipitation, i.e., minor increases in winter precipitation (less than 10% by 2050) and medium decreases in summer precipitation [
30]. These changes will most likely affect water supply, groundwater resources and recharge, soil water balance, surface runoff, nutrient loads, flow dynamics, hydromorphological conditions, water storage, and flood risk in the Elbe RBD [
28].
6. Requirements from the Governance Perspective
In the political science literature, there is considerable agreement among decision makers and experts “about which bottlenecks are the most crucial when it comes to shortcomings in WFD implementation: insufficient land reserves, lack of intersectoral communication and integration, insufficient staff capacities and inadequate financing” [
54] (p. 21). Furthermore, “rapid turnover is also a bottleneck—even if not a characteristic of the system itself—because it causes congestion in a system as well as inefficiencies or significant delays” [
54] (p. 21). Other studies show how resilient existing territorial institutional arrangements are and how difficult in terms of power, and how time-consuming it is to implement real water governance measures and processes on a river basin scale [
55]. Similarly, effective and legitimate participatory models during WFD implementation develop slowly [
56].
These governance categories do not reflect the spirit of our SES features; assessments such as the EU Fitness Check do even less. To put it in other words, implementing more (in number) and more far-reaching (in impact) measures targeted at global warming effects increasing actual practical action sets very high standards for water governance in practice. Fulfilling our criteria is an urgent task for future water governance. Nevertheless, the WFD itself has, as our research results related to the Elbe basin show, the institutional potential to fit to all SES features.
Analysing global warming impacts in the WFD and corresponding river basin management might draw lessons from the implementation of its daughter directive on flood risk management, the EU Floods Directive (FD). Established later in 2007, the FD did not oblige water governance stakeholders to systematically consider climate change projections in management plans. The result is that Member States and River Basin Districts include climate change projections in management plans, but not in a harmonised manner [
57,
58,
59]. For example, comparative studies show that too many different methods for assessing climate change impacts are in place by 2020. Each basin and member state projects differently, which leads to even more certainties for flood management in times of global warming [
57]. However, global warming effects impact flood risk directly and to such a broad extent that its full consideration in management is urgently necessary. Consequently, the FD Fitness Check finds that more coordinated flood prevention in line with climate change projections is needed.
7. Conclusions
For each SES feature, we present the results in separate sections. Each section starts with a detailed explanation of the feature properties, followed by an elaboration on the feature’s role in the European Water Framework Direction and global warming context. Subsequently, the analysis specifically for the Elbe RBD follows; therefore, we provide a section that presents aspects where the respective SES feature is successfully taken into account in the Elbe River basin, followed by a section indicating areas where the consideration is still insufficient. Furthermore, we present scores of the semi-quantitative assessment providing an overview of how feature properties were considered.
Our research question—With regard to global warming, to what extent does water management in the Elbe River Basin District take the features of social–ecological systems into consideration?—is answered by the scored properties of the SES features; therefore, we consulted experts and analysed the framework and existing plans. At that stage, and for that basin, we find that the WFD implementation process does not address global warming issues explicitly enough. Provisionally, we can only conclude with rather general recommendations regarding the six features, using our results as guidelines for future WFD implementation cycles:
In the future, only the full recognition, for example, of scale and openness can ensure effective water management in the Elbe River basin. The hierarchical structure already allows for different water management needs such as drinking water supply, wastewater treatment, energy supply, and irrigation water for agriculture to be reconciled. Broader, cross-scale impacting effects can be considered. If this is to be further improved and ensured in the future, local level needs and objectives across sectors must be consistent with overarching goals; therefore, it is necessary to consider the scope of global warming in a more fundamental way.
The overall consideration of context dependency in the Elbe River basin is good. Challenges that still occur in relation to context are related to inflexible infrastructure.
To consider slow and fast variables that result in
non-linearity, uncertainty, and unpredictability, and to better understand global warming impacts and the interplay between different sectors in the Elbe River basin, different methods, such as vulnerability and impact analyses and generalised modelling, should be applied. These methods increase SES understanding despite restricted system knowledge [
9]. So far, such analyses have not yet been applied on a larger scale in the Elbe River basin, and are still associated with great uncertainties, resulting in only limited consideration of the feature at present [
30].
To increase the consideration of
dynamics, which is of particular importance for the long-term perspective, it is necessary to identify potential tipping points; therefore, we must determine the direct impacts of global warming in the Elbe River basin first, which can be achieved by conducting a consistent climate impact assessment at the river basin level [
33]. In this context—and regarding vulnerability and sensitivity analyses—it is essential to consider dynamics as an independent but interacting property. Furthermore, it must be ensured that the gained insights into alternative stable states have wider practical implications than the current insight. The assessments must be carried out systematically at a consistent level to obtain the bigger picture.
To analyse the context of water availability and water demand, which is
constituted relationally (including global warming impacts and different kinds of water use), long-term management models are already applied in the Elbe River basin today [
30]. Such models are a good starting point to consider interactions. Within these models, however, the focus should be shifted towards further exploring the nature of these interactions—this is particularly important, for example, when it comes to identifying areas where explicit management for consistency is to be strengthened to prevent future water use conflicts. Methods such as network analysis and agent-based modelling are potentially adequately supportive of relationality [
22].
For improving WFD implementation in general, it seems reasonable for us to explicitly include global warming impacts in assessment, objectives, reference conditions, and planning of measures. From our perspective, it would be necessary to add an obligatory precautionary component (exceeding the timeframe of 6 years) to provide the WFD with a long-term perspective—this would allow us to clarify and identify global warming effects, recognise self-organisation capacities, and evaluate adaptation measures appropriately.
The preparation of the new planning cycle at the Elbe River basin, which was published in early 2021 (directly after our research period), already addresses the impact of global warming more explicitly. How SES features are addressed here should be analysed with the typology we have presented in this paper.