Green Empowerment: Citizens’ Willingness to Contribute to the Nature Restoration Law’s Implementation in Urban Areas

Abstract

Fulfilling the requirements of the EU’s Nature Restoration Law in urban areas will require not only planning and administrative action but also citizen engagement. The paper at hand analyzes citizens’ willingness to change the urban environment in a study consisting of a pan-European survey with an integrated choice experiment. The majority of the 7045 respondents would support a rapid urban greening process and are willing to contribute to its financing. The latent class analysis reveals four different classes with different interests and willingness to engage: Class 1 supports the development of green areas and nature-based solutions in general and under nearly any conditions; Class 2 is sensitive to costs and accessibility disruption. For Class 3, participation will increase their interest and willingness to pay. Only Class 4 (8.6% of sample respondents) is against or disinterested in the development of urban greening. The findings demonstrate that the European goals are strongly supported by the majority of urban residents and highlight a significant interest in their implementation, to which they are also willing to contribute. These findings should encourage local initiatives and the local administration to implement the process of urban greening and the goals of the nature restauration law in a more ambitious manner.

1. Introduction

A critical balance has been identified by the European Environment Agency with regard to the state of nature in Europe and its cities [1]. It shows that the objectives of the Birds and Habitats Directives have not been achieved after 45 and 32 years, respectively [2]. In 2020, only 15% of protected habitats were in good condition and 39% of protected birds and 63% of other protected species were living in inadequate or poor conditions. In the case of bee and butterfly species, 33% are in decline, with 10% of these species threatened with extinction [1]. This has critical consequences for ecology and economy, as almost 5 billion euros of annual agricultural production in the EU is directly attributable to pollinator insects. Examining the ecosystem also points to numerous barriers that restrict the continuity of watercourses despite the Water Framework Directive, with consequences for fish, insects, small crustaceans and aquatic plants. Taking into account these past developments and frameworks, the Nature Restoration Law (NRL) has been put forward [3]. The objectives of the NRL are deliberately linked to the existing protection concepts of the Birds Directive [4] and the Flora–Fauna–Habiatat Directive [5], as well as the objectives of the Water Framework Directive [6]. The aim is to reverse the trend in biodiversity loss and improve implementation through clearly formulated and binding requirements. In addition, measures to be taken should strengthen the resilience of ecosystems to climate change and make better use of the instruments of natural climate protection. The NRL thus differs from previous sectoral strategies and pursues a landscape-wide approach that links the restoration of nature with various forms of land use while creating added value not only in protected areas, but in the entire landscape. For the first time, urban areas are also significantly incorporated. An integrative view on the environment instead of an isolated conservation strategy is also a novel approach. The NRL highlights the necessity to involve other forms of land use, such as agriculture, forestry, measures for climate change adaptation and green energy, as well as initiatives in urban environments.

This paper is one of the first to examine the initiatives of the NRL expected to improve conditions in urban environments by asking citizens across Europe about their willingness to contribute. The NRL is perceived as one of the most important and most ambiguous strategies that the European Union has ever started. Considering this, we ask whether these goals are too ambiguous and perhaps too far detached from the interests and needs of the urban population. We seek to understand whether and to what extent the desired European goals for urban areas are supported by European urban populations.

2. State of Knowledge

2.1. Goals Within the Nature Restoration Law Addressing Urban Environments

Urban ecosystems account for around 22% of the EU’s land area, and the majority of citizens in the European Union live within these boundaries. Urban ecosystems provide important habitats for biodiversity, especially for plants, birds and insects, such as pollinators. At the same time, nature-based solutions (NbSs) also provide vital ecosystem services in the areas of flooding and heat island effects, cooling, leisure and recreation, water and air filtration as well as climate protection and adaptation to climate change. Therefore, the preservation and promotion of urban green spaces and NbSs is an important objective within the NRL. The expansion of urban green spaces can improve the habitat quality of urban ecosystems. Urban green spaces include, but are not limited to, urban forests, parks and gardens, urban farms, avenues, meadows and hedgerows. To enhance eco-system services, the NRL aims to ensure that the amount of urban green spaces, especially areas with tree cover, is maintained or expanded.

Urban ecosystems are explicitly addressed in the timelines put forward in Article 8 and 14 of the NRL, which states that there is to be no loss of urban green spaces or canopy cover by 2030 compared to 2024, with some exceptions for cities which currently exceed 45% green spaces in city centers and 10% tree canopy cover [7]. Beyond 2030, member states shall commit to expanding canopy cover, urban green spaces and NbSs onto buildings and infrastructure in urban ecosystem areas and conduct monitoring at regular intervals until the levels in Article 14 (5) are achieved [7].

The tasks are addressed to “local administrative unit” (LAU), a low-level administrative division of a member state, below that of a province, region or state. Article 4 of the NRL also provides definitions of various types of urban areas which incorporate greening measures and defines standards for urban green spaces and tree canopy cover as well. The NRL sees green spaces as not only including larger plants such as trees and bushes but also smaller ones such as mosses and even includes aquatic features such as ponds. The goals of Article 13 include major tree planting efforts to increase the resilience of urban areas and reduce climate change impacts and urban heat island effects. With these effects in mind, these new green areas are viewed as NbSs. With this goal, member states commit to planting trees as NbSs to ensure these ambitious plans are met [1,2,7].

The NRL calls member states to extensively map urban ecosystems and develop restoration plans at a national level. The development process is to be based on the latest scientific evidence and be a transparent process as put forward in Chapter III [7]. Finally, the NRL includes challenging monitoring approaches to ensure the implementation of the goals: Article 20 describes monitoring the growth and expansion of urban green spaces and tree canopy cover [7].

The NRL has set clear and ambitious goals for urban greening and the use of NbS to address urban issues. It has also identified LAUs as responsible units for implementation and monitoring processes.

2.2. Awareness and Acceptance of the NRL and Its Goals

Previous studies analyze the support of conservation strategies and reactions to the NRL. Prior to the decision-making about the NRL, a large pan-European survey was started to understand the preferences of the European population, revealing significant support for the conservation goals [8]. In the six countries included in the survey, the NRL received especially high support from citizens in Poland, Hungary and Italy while citizens in the Netherlands, Sweden and Finland were slightly less supportive. Overall, only 6% of the respondents opposed the adoption of the law [8].

A representative survey conducted by WWF (World Wildlife Fund) in Austria (N:1000) showed similar findings [9]. Here, large sections of the population were also concerned about the loss of nature (72%). For 77%, the protection and restoration of nature is of central importance. A total of 74% of respondents called for binding targets to restore nature. Eight out of ten people considered “an intact natural environment to be important for long-term economic development and indispensable for the production of important goods such as food, materials and medicines.” In addition, 81% of participants stated that health and well-being are based on intact nature. Therefore, it is not surprising that 83% agreed with the statement that “the protection and restoration of nature is in the long-term interests of people in Austria” [9].

A recent Nature Awareness Study published by the German Federal Ministry of Environment and the Federal Agency for Nature Conservation [10] also underlines the perceived need to restore ecosystems and the importance of natural climate protection for Germany. The nationwide representative study presents a direct comparison of data on the awareness of adults and young people. A total of 2411 adults aged 18 and over and 1003 young people aged 14 to 17 were surveyed in fall 2023. The selected results confirm the positive assessment of the NRL in other European member states. In Germany, the majority of respondents believe that a transformative change is necessary to tackle the natural, environmental and climate crisis (“yes” and “rather yes”: 74%) [10] (p. 47). Young people aged 14 to 17 also see the need for transformative change with a majority of two-thirds (66%). The Nature Awareness Study also shows that the majority of the population is convinced that the state of nature and landscape has deteriorated over the last 20 years. Currently, 53% of the adult population sees a deterioration, compared to only 27% in 2011 [10] (p. 62). Against this backdrop, 85% of adults and 80% of young people are clearly or at least somewhat of the opinion that the conservation and restoration of ecosystems is a social task that should be prioritized [10] (p. 65).

With regard to measures in urban areas, it is important to note that the German population also supports state funding measures for natural climate protection [10] (p. 54). A total of 88% of adults and 84% of young people completely or somewhat agree with such measures.

Conflicts are discussed in the context of land use and economic activities [11]. The potential for tension is seen in the necessity to change land currently being used for economic or other purposes into areas reserved for restoration [11]. Furthermore, critiques concentrate on difficulties related to the implementation process, especially for federalist member states like Austria, where planning and conservation tasks lie partly with the provinces [11]. Inconsistencies and varying priorities related to restoration plans, measures and their implementation are expected across the EU [11,12]. However, the implementation of the NRL in cities has received little attention so far. This study can close a significant research gap here.

2.3. Purpose of This Study and Concept of Empowerment

Urban greening is a challenging task involving city planning, landscape architects, moderation teams and a lot of time and money for planning, moderation and implementation. Many papers have analyzed the complex processes involved, the many factors hindering positive outcomes and the reasons for limited implementations [13,14,15]. Despite the high acceptance for new green infrastructure in cities, the literature is full of examples and arguments underlining the many difficulties and challenges, such as the following:

• Concerns about the perceived unproved effectiveness of NBS [14,16,17];
• Lack of trust in urban NBS and skepticism among stakeholders [13,15];
• Complex stakeholder processes and collaborative challenges [13];
• Limited financial resources for NBS [13,18];
• Missing concepts for built-up areas, meaning that greening takes place only in cases of new investments [13];
• Competition over urban spaces hindering the development of NbS;

Complex planning systems and policies resulting in project-based approaches [13].

In view of these challenges, the concept of empowerment might offer insights. Following the concept of empowerment, it might be feasible to enhance tree planting in cities and the enlargement of green areas. We adopt the understanding of Rappaport [19], who defines empowerment as a process: “the mechanisms by which people, organizations, and communities gain mastery over their lives and living conditions”. Zimmerman [20] states that “Empowerment theory connects individual well-being with the larger social and political environment.” Furthermore, Kieffer [21] adds that empowerment can be understood as “an unabashedly political conception of human being—addressing the person as ‚citizen’ embedded in a political as well as social environment” [21] (p. 10). With this understanding in mind, it is of interest to study whether an understanding of the feasibility and joined goals might form the basis for a change in urban environments.

Therefore, the paper at hand asks the important “what if” question: what would happen if we knowingly ignored all these hindering aspects and focused instead on the benefits for the climate, quality of life and other similar advantages?

What if …

• we assume that, on average, there are significant benefits regarding air quality and ignore differences in plant species, design, etc.
• we assume that for simple tasks such as street greening, a complex and difficult stakeholder process is not required.
• we make an agreement with our local population to pay for our benefits by ourselves,
• we make decisions independently from external investment.
• we assume that our policy is easy, for instance, to change certain parking areas into locations for street greening.

Would this strategy of empowerment be acceptable for the urban European populations? Is it too extreme? Who would support this fast step forward and who would refuse?

Therefore, our main hypotheses are as follows:

• Simple solutions, such as a street greening process of average effectiveness, without special effects on biodiversity and with medium challenges in terms of time and financial payments, would be supported by the majority of European citizens.
• Based on different classes, tailored solutions of high acceptance can be developed and will facilitate fast implementation.
• The awareness of common goals is a crucial precondition for local empowerment and fast implementation.

3. Methodology

The survey included 24 general questions and a discrete choice experiment (DCE). Within the general section, questions about the living conditions, distance to green areas, perception of climate change, experiences with heat and socio-demographics were included. The choice experiment covered trade-offs necessary when planning and developing NbS. Choice experiments as part of the survey represents a quantitative, choice-based form of survey from the field of behavioral economics [22]. This methodological approach offers excellent opportunities to investigate complex socio-economic issues, management options and development scenarios. The method is particularly suitable with regard to uncertainties and risks in connection with climate change, among other things [23]. Both LatentGOLD5.1 [24] and SPSS 28.0 [25] were used in the analysis.

However, the requirements for the attributes and the respective levels in a choice experiment are challenging. Only those attributes which can be assumed to be of importance to the respondent are to be selected. The following table (

Table 1. Criteria for the attributes in a choice experiment (following [26] (p. 133), [22]).

Criteria	Explanation
Relevance	The attributes should cover relevant aspects for the decision-making in the eye of the respondent.
Influenceability	The attributed must be influenceable so that a potential provider of the environmental good can also control them.
Independence	In order to avoid distortions, the independence of the attributes from one another should be guaranteed, i.e., the perceived benefit of a property characteristic should not be affected by the characteristics of other attributes.
Market realism	The closer the experiment resembles the actual situation or market, the higher the content validity and the acceptability of complex choice tasks.
Contemporary relationship	The subjective perception of a characteristic by the respondent can be compensated by the change in another characteristic.
No exclusion criterion	A property characteristic must not be an exclusion criterion, because otherwise the compensability is no longer guaranteed.

) summarizes the main indicators that need to be considered when designing a choice experiment [26].

The DCE is composed of eight attributes (

Table 2. Overview of attributes and levels (no attribute restrictions were required in relation to the four types of NbS).

Attribute	Level
Type of NbS	Communal garden
	Street greening
	Rain garden
	Green corridor
Micro-dust reduction	−5%
	−10%
	−20%
	−30%
NO2 reduction	−3%
	−10%
	−35%
	−50%
Temperature reduction (in summer)	−0.5 °C
	−2 °C
	−4 °C
	−6 °C
Biodiversity level	Low
	High
Accessibility of home by car	No extra time
	+5 min
	+10 min
	+20 min
Waste bin charge increase	10 EUR
(annually per household)	30 EUR
	50 EUR
	100 EUR
	150 EUR
	200 EUR
	250 EUR
Participation in design process	Yes
	No

), which are visualized in Figure 1 below and were introduced into the survey by previous (learning) questions. The first attribute presents four different types of urban green (street greening, green corridor, community garden and rain garden) representing different functionalities, followed by three attributes describing the possible effects by the urban green on micro-dust, NO₂ and temperature reduction. The presented ranges are based on a related literature review [27]. Furthermore, the possible effects on biodiversity were included. Two attributes introduce the possible negative effects of urban greening such as the personal contribution of payments (using an annual waste bin charge, already used in Germany and Poland) and time (covering a possible change in time when accessing the home after the greening).

The choice sets are based on a statistical design developed with SAS 9.4 software [28] consisting of 64 choice sets. The survey was pretested in the participating countries. Data collection was panel-based and carried out in seven European countries (Austria, the UK, Hungary, the Netherlands, Poland, Slovenia, and Greece) with roughly 1000 respondents per country. The survey was addressed to respondents living in cities with more than 20,000 inhabitants in accordance with European Union policy framework [29]. Each respondent had to answer six choice sets. We conducted the statistical analysis using SPSS 28.0 [25] and the analysis of the DCE with LatentGOLD5.1 (the obtained part-worth utilities and model fit can be found in the Appendix A) [24]. Based on the analysis with LatentGOLD5.1 we defined three different classes. The part-worth utilities were integrated into an EXCEL-based decision support tool (DST) for visualization purposes (see Figure 2 as an example of the DST in use). In order to visualize the percentage of respondents selecting the “neither” option, the two sets must be the same.

4. Results

4.1. Description of the Sample

The final quality-controlled sample consisted of 7045 respondents. Furthermore, a deeper analysis with LatentGOLD was conducted, revealing four latent classes with different preferences. An overview of the sample is provided in

Table 3. Sample overview and information about the latent classes (Class 1 supports any kind of urban greening, Class 2 is mainly interested in effective green areas, Class 3 seeks cost effective and collaborative solutions, and Class 4 is more likely to be disinterested in urban greening). Further explanation is provided in Section 4.2.

	All (n = 7045)	Class 1 (n = 3774)	Class 2 (n = 1565)	Class 3 (n = 1133)	Class 4 (n = 603)	Chi2
Gender						0.008
Male	51.6%	52.8%	52.1%	51.7%	48.9%
Female	47%	46.9%	47.6%	47.4%	50.9%
Diverse	0.2%	0.1%	0.3%	0.3%	0.2%
Prefer not to say	1.2%	0.2%	0%	0.6%	0%
Age						<0.001
<25	10.9%	13.2%	10.1%	8.1%	3.8%
25–34	20.2%	24.3%	18.7%	12.6%	12.9%
35–50	29.5%	29.4%	32.2%	26.7%	28.2%
51–65	26%	22.4%	25%	32.8%	38.4%
>66	13.5%	10.8%	14%	19.9%	16.7%
Household size						<0.001
1	18.6%	17.1%	18.2%	21.8%	25%
2	35.5%	33.8%	36%	41.2%	37.4%
3	21%	22%	22.1%	17.4%	20.5%
4	17.4%	19.8%	16.8%	13.7%	12.1%
5+	6.7%	7.2%	6.9%	5.9%	5%
Children						<0.001
Yes	32.3%	35.6%	32.6%	26.3%	24.5%
No	67.1%	64.4%	67.4%	73.7%	75.5%
Cars (household)						0.141
0	15.8%	15.3%	14.9%	17.5%	18.1%
1	54.4%	53.5%	54.4%	56.3%	56%
2	24.9%	25.8%	26.1%	22.1%	21.7%
3+	4.8%	5.4%	4.6%	4.1%	4.2%
Education						<0.001
None completed	0.2%	0.3%	0.1%	0.4%	0%
Primary	1.5%	1.4%	1.5%	1.4%	2.2%
Secondary	28.1%	26.2%	29.6%	31.7%	29.6%
Trade/vocational	18.7%	16.8%	17.3%	23.8%	24.5%
University	50.6%	54.5%	40.8%	41.5%	42.8%
Prefer not to say	0.8%	0.7%	0.6%	1.2%	1%

together with an overview of the four classes (see Section 4.3 for a detailed description of the latent classes).

Slightly more male than female individuals participated. Age distribution was slightly older, with a large portion of respondents between the ages of 35 to 65. Only a third of households had children under 18 in them. Generally speaking, the sample was well educated, with 50.6% holding a university degree and further 18.6% having completed trade or vocational training. Car ownership was high—only 15.8% of the households did not own a car.

The respondents were distributed across different city sizes was almost evenly. The majority of respondents lived in city centers and urban districts. Around 45% of respondents lived in high-density developments (tower block, closed block). Just under a third lived in older buildings built before 1960. Another third lived in buildings from the 1970s and 1980s, and a further third resided in modern apartments built after 1990. The majority rated the green areas in the surroundings of their homes as positive. However, about 40% spent less than an hour per week in green areas. Finally, 86% of the respondents stated that they have had experience with heat waves.

4.2. General Findings

Connecting to the idea that LAUs must be empowered to achieve the rapid implementation of the NRL, we first analyze the sample as a whole to determine under which conditions tree planting and greening in European cities would be supported by the majority. Only 4% of respondents are entirely against greening measures. Looking at the four types of NbS, street greening is supported by most respondents, followed by green corridors, rain gardens and, finally, communal gardens (see the Appendix A for part-worth utilities). When assuming a reduced effectiveness of temperature reduction and air quality, a waste bin charge of 30 euros annually and a reduced accessibility of 10 min, only 4% of the respondents would choose to opt out (Figure 2). This is assuming that the design process is participatory. Without participation, the situation changes and up to 7% would opt out and select neither—a clear indication of the high relevance of planning process design.

Respondents’ attitudes towards greening opportunities remain positively inclined when effectiveness is reduced, charges are higher and accessibility is decreased. As seen in Figure 3, even if the charge is raised to 100 euros annually per household and the detours to their homes were at the highest level (+20 min), 80% of respondents were still in favor of the presented street greening.

4.3. Latent Class Analysis

A deeper analysis with LatentGOLD revealed four latent classes with different preferences which can be described in terms of their characteristics. They also demonstrate different preferences (Figure 4).

Class 1 (n = 3744; 53.1% of the sample) consists of respondents who are largely in support of urban greening. The effectiveness, cost and accessibility are all of limited relevance to their decision-making. They favor biodiversity enhancement, and participation in the design is of low relevance. As Table 3 and

Table 4. Description of urban surroundings for all and latent classes (Class 1 supports any kind of urban greening, Class 2 is mainly interested in effective green areas, Class 3 seeks cost effective and collaborative solutions, and Class 4 is more likely to be disinterested in urban greening). Further detailed explanation is provided in Section 4.2.

	All (n = 7045)	Class 1 (n = 3774)	Class 2 (n = 1565)	Class 3 (n = 1133)	Class 4 (n = 603)	Chi2
City Size						<0.001
20,000–50,000	18.9%	17.5%	19.6%	22.1%	20.4%
50,001–100,000	17.7%	17.5%	17.3%	18.6%	17.7%
100,001–250,000	19.5%	18.8%	20.2%	21.8%	18.6%
250,001–500,000	21.9%	24.5%	20.3%	18%	17.2%
500,001–1.5 mil.	17.4%	17.3%	18%	16.2%	18.7%
>1.5 mil	4.6%	4.5%	4.6%	3.4%	7.3%
City district						<0.001
City center	31.9%	35.9%	28.8%	27.2%	24.9%
Urban districts	41.9%	41%	45.3%	41.3%	40.5%
Suburbs	26.1%	23.2%	25.9%	31.4%	34.7%
Type of housing						<0.001
Detached house	21.8%	13%	20.6%	21.6%	17.8%
Semi-detached	12.1%	11.6%	10.4%	13.8%	15.6%
Row house	19%	17.1%	18.9%	23.1%	23.2%
Tower block	15.5%	16.4%	15.6%	13.7%	12.7%
Closed block	29.1%	29.7%	32%	23.7%	27.2%
Other	2.6%	2.1%	2.4%	4%	3.6%
Year built						0.003
<1914	4.5%	4.3%	4.2%	5.2%	5%
1914–1939	6.9%	6.2%	6.6%	8.5%	8.5%
1940–1969	18.3%	17.6%	18.2%	19.3%	20.3%
1970–1989	35.1%	34.2%	36.5%	35.2%	36.4%
1990–2009	24.3%	26.1%	24.4%	21%	19.3%
>2010	11%	11.5%	10.1%	10.8%	10.5%
Amount of green						0.583
Excellent	22.8%	23.5%	21.5%	23.1%	21.7%
Good	56.7%	56.2%	56.5%	57.6%	58.4%
Poor	19.1%	19%	20.6%	17.5%	18.4%
None	1.5%	1.4%	1.4%	1.8%	1.5%
h/week in green						<0.001
<30 min	21.5%	18.5%	25.9%	25.9%	30.2%
1 h	22.7%	23.7%	20.5%	20.5%	21.3%
2–4 h	32.7%	33.6%	31.9%	31.9%	30.7%
4–7 h	13.7%	14.7%	11.6%	11.6%	9.8%
>7 h	9.3%	9.5%	8.8%	10%	8%
Heat wave experience						0.165
No	13.2%	13.2%	11.6%	16%	12.1%
Yes	86.8%	86.8%	88.4%	84%	87.9%

show, this class is, on average, younger than Classes 3 and 4. This class also consists of a high number of families and larger households (one third of the respondents have children in their households). Their education level is generally high. In addition, the majority of these respondents live in dense housing conditions and highly urbanized environments. Time spent outdoors is the highest for these participants compared to the other classes, explaining their interest in urban greening (57.5% spend more than 2 h per week outdoors).

The preference for greening is shown in Figure 5, which illustrates that only Class 1 will not opt out of suggested greening measures, even though costs would be high and accessibility would be severely impacted.

Class 2 (n = 1565; 22.2% of the sample) pays closer attention to the effectiveness of a solution to reduce temperature and micro-dust. However, looking at the socio-demographic conditions, this class shows many similarities with Class 1. This class is also younger than the average sample (37% under 45 years). A low number were single households and one third comprised households with children. Participants from this class also mostly lived in densely populated areas (city center and urban districts). A total of 47% lived in tower blocks and closed blocks. Compared to Class 1, they spent less time outdoors. Therefore, it is not surprising that biodiversity and types of green area are of less importance to them (Figure 6). Their willingness to pay or sacrifice accessibility to their homes are noticeably lower than Class 1 (see Figure 5). Compared to Classes 1 and 3, we can see that they are very cost sensitive and that retaining adequate accessibility is of high importance.

Class 3 (n = 1133; 16.1% of the sample) is interested in the type of greening and the reduction in micro-dust. Biodiversity enhancement, ease of access and low costs are also relevant for decision-making. This leads to greater opt-outs than in Classes 1 and 2, as seen in Figure 7, where participation is omitted and charges are foreseen. This class is characterized by respondents who are older than those in Classes 1 and 2. The proportion of single and small household is significantly higher. Children are resident in only 25% of households. Their living conditions are less dense and urbanized since a high proportion live in the suburbs and in detached houses.

In contrast to other classes, this class also pays particular attention to whether a participatory planning process is utilized. They are more likely to choose an option with elements of participatory design. Figure 7 illustrates the high relevance of this factor, as about 48% choose the “neither” option in cases with a lack of participation opportunities.

Class 4 (n = 603; 8.6% of the sample) is characterized by respondents who are against, or strongly disinterested, in greening measures. They continuously opt for neither option regardless of type, efficiency, cost, accessibility or participation and cannot be swayed. Although they represent only a small proportion of the sample, they are strongly negative in their decision-making, as can be seen in Figure 5, Figure 6 and Figure 7. This class is also characterized by higher average age and lower educational levels and has the highest share of single households. Their average housing situation is generally characterized by older buildings and dense structures. A total of 51% of the respondents in Class 4 spend less than an hour per week in green areas.

5. Discussion

5.1. Awareness, Acceptance and LAU Empowerment

The present study confirms the overwhelmingly positive evaluation of the main goals of the NRL presented in other studies [9,10] and, therefore, many of the discussed concerns should be reconsidered. The perceived concern that NBS may be ineffective [14,16,17] is not seen as reason to decide against urban greening by the majority of European urban residents. The same applies for the often-mentioned lack of trust in urban NBS and skepticism among stakeholders [13,15].

Furthermore, the results demonstrate that there is a high acceptance among citizens to personally contribute in order to enhance the environments in their neighborhoods. They are willing to accept annual charges or intrusions regarding accessibility to their homes by car. This confirms that there is an opportunity to overcome the currently limited financial resources for NbS and greening efforts [13,18]. Citizen’s willingness to contribute should be seen as an opportunity for built-up areas, which—in contrast to investor-financed new residential areas—have often been neglected when it comes to urban greening [13]. Urban greening often involves complex planning approaches, and while stakeholder involvement [13] was relevant for many respondents of the study, one may ask whether participatory planning adds further complexity to a situation which residents are already in favor of. Based on the results, one can conclude that, in general, LAUs can be empowered to facilitate the planning and implementation of greening measures, which are backed by a large majority of the surveyed population

5.2. Local Empowerment and the Opportunities for Urban NRL Implementation

Considering these results, the opportunities for growing the percentage of green areas and increasing tree planting in urban areas are good and well accepted by the population. The number of respondents who were completely against the concept was generally very low.

There is a large consensus among urban residents across Europe that the implementation of NbS and urban greening on a small scale, in neighborhoods and districts, and along streets is a welcome development. There is no “great enemy”, as some administrations or planners may fear. Awareness needs to be spread that empowerment does not always have to comprise grand gestures, but can be found in small steps, with smaller scale implementation or events which will grow into widespread implementation [30] (p. 185). When citizens see that their participation achieves outcomes and the opportunities to build communities of solidarity exist, they tend to be more engaged [30] (p. 186).

The result of empowerment processes at the structural level is a “successful interplay of individuals, organizational associations (citizens’ groups, self-help initiatives, social institutions) and structural framework conditions (large administrations, municipalities, city districts or other large communities)” [31] (p. 144). This should result in collaborative, synergetic processes between different participants [32]. Such empowerment processes are characterized by “micro-political determinants”: they succeed when “mutually supportive communication structures can be established and maintained in and between organizations, groups and projects”; they begin with steps “on a small scale”, not in the “big picture” [31] (p. 153). The presented data across European cities support the idea that these types of implementation processes are supported by a vast majority of urban populations. In this context, sociological research emphasizes that the initially perceived or structurally mediated “different interests” are seen as capable of consensus. In this respect, this study makes a hopefully crucial contribution [32,33].

5.3. Methodological Considerations and Limitations

One limitation of this study is the fact that only 7 of the 27 European Union member states were included in the study. However, the study was careful to include countries distributed across the continent in order to understand possible influences of climate change and related urban heat stress. Furthermore, it is a possible limitation that the education level of the overall sample did not match levels reported for the whole European Union [34]. The number of highly qualified respondents was significantly higher (50% in our sample compared to 33% of total residents, according to Eurostat [34]). On the other hand, the percentage of less qualified respondents was also higher in our sample (30% compared to 20% of total residents, according to Eurostat [34]). Therefore, we believe that the overall findings do not overestimate willingness to cooperate.

In addition, we applied a choice experiment with many attributes, which can be considered a cognitively demanding task for respondents. Therefore, despite the careful preparation and selection of our attributes in line with the literature [26,34], this might be perceived as limitation. However, the design of a choice experiment in most cases requires a trade-off between completeness and reducing complexity. The relevant literature generally suggests between four and eight attributes [33]. However, there is little consensus and even fewer empirical data available regarding the optimum level of complexity. Research findings from Louviere et al. [22] confirm the selection criteria by Müller [26], highlighting the significant relevance of realistic constellations in choice sets. Louviere et al. [22] argue in this context that the closer the experiment resembles the actual situation or market, the higher the content validity and the more acceptable the choice tasks of higher complexity. Furthermore, the design of the survey, the inclusion of learning questions preceding the choice experiment and careful pretesting with a variety of participants ensured the reduction in the cognitive challenges for respondents. Finally, implementation through country-specific panel recruitment was beneficial, as such respondents are generally more motivated to participate and are typically used for complex survey questions.

The choice experiment was a suitable tool for understanding the influencing factors, such as the role of biodiversity enhancement or participatory approaches and their relevance in the decision-making process in general and for different latent groups in society. The literature review on DCE methodology regarding the careful selection of relevant attributes, which accurately reflect real-world decision-making, strengthened the design. In this DCE, we introduced attributes on accessibility to an individual’s home, wastebin charges and greening effectiveness (temperature, NO₂, micro-dust), which were all relevant to the scenario provided to the respondents.

6. Conclusions

The high level of social support for NRL is also apparent in the survey on NbS in urban areas. The results of the survey highlight the feasibility of the European objectives of the NRL and the significant support for its goals, which has been questioned before. The clearly positive results encourage us to overcome the frequently described hurdles and concentrate on feasible solutions. Coming back to the “What if” questions posed in the introduction, we can state that the positive evaluation and willingness to contribute does not depend on high efficiency and that design questions may also be overrated by the experts involved. Citizens are willing to contribute in various ways, both through monetary payments and time. However, opportunities to contribute to the process in a participatory manner are important for many people. Therefore, we can confirm our first hypothesis, namely that even simple solutions, such as street greening of average effectiveness, without any special effects for biodiversity and with medium time and financial payments, would be supported by the majority of European citizens. However, the results also show that based on different classes, tailored solutions for high acceptance can be developed, which may facilitate fast implementation. Therefore, Hypothesis 2 also is confirmed. The final discussion showed that our findings may support local empowerment and rapid implementation. Overall, we can see that the European goals set out in the NRL follow the interests and needs of the urban population and are certainly not too ambitious.