What if climate communication could enhance support for unpopular but necessary policies? Valerie Dewaelheyns, Pieter Raymaekers, Florian Lange, Ben Somers and Trui Steen show that a collective action framing can increase public acceptance of ambitious climate adaptation policies and strengthen citizens’ belief in society’s collective power to tackle climate change.
Copyright: Kirsten Bomans
As leaky as a sieve
Can you imagine struggling for drinking water just three months after a year of relentless rain? This is happening now in Flanders, the northern region of Belgium, where 2024 was the wettest year on record followed in 2025 by the driest spring in 132 years. Although the impact of this drought is currently less severe than expected thanks to the previous abundance of rain, Flanders is facing the immense task of better managing its water system in a climate that is changing increasingly fast and unpredictably.
Because of the high share of paved surfaces combined with a water infrastructure designed to remove excess water to the sea as quickly as possible, Flanders is what experts call ‘as leaky as a sieve’. One solution is to capture and store more rainwater in the groundwater table. This requires, among other things, increased depaving of private gardens by citizens. These gardens cover a substantial 12% of Flemish space, and one fifth of garden area is paved.
The urgency of climate change demands hard policy interventions. Such policies have been shown to be more effective than softer interventions, yet policy makers hesitate. Hard policies are often unpopular, and citizens and policy makers tend to view private gardens as untouchable.
This raises the question: how can governments increase support for hard and unpopular climate adaptation policies in private spaces like gardens?
Can I, or can we?
One of the main challenges in motivating people for climate action is convincing them that their individual efforts contribute to collective impact. In the end, it is the collective result of many individual efforts that drives meaningful change.
With this in mind, we designed an information intervention: an infographic presenting facts and figures on private paving; how private paving is associated with heat, drought and flooding; and the impact of depaving 10m² of the garden. Importantly, we framed this infographic in two different ways, highlighting either an individual or a collective perspective (see Figure 1).
Figure 1: Representation of the infographics used in the experiment
Source: Dewaelheyns, V. et al (2025). Notes: The left infographic holds the collective frame, the right infographic the individual frame. Both infographics are translated from Dutch. The original infographics are available from the corresponding author upon request.
Our online survey experiment involved 3,389 Flemish citizens, who were randomly allocated to one of the following:
- Control group: no message
- Individually framed information
- Collectively framed information
We investigated with high precision whether these infographics influenced citizen’s support for four hard policy instruments targeting private paving:
- A more stringent permit policy;
- A more stringent enforcement policy;
- Introduction of a yearly financial contribution based on the share of paving in the garden; and
- Introduction of a subsidy for private depaving.
We also combined quantitative and qualitative data, with 847 (25%) respondents providing their comments on garden depaving policies in the survey. We analysed their reflections on the policy measures.
Yes, we can! Collective framing builds support for hard climate policies
Collective framing works: the collectively framed infographic significantly raised support for stricter paving permits, and a new financial contribution based on the garden’s paved area.
Further, the effectiveness of collective framing extended beyond policy support. It significantly boosted both personal and collective self-efficacy, as well as collective outcome expectancy (see Figure 2). In other words, the collective frame not only strengthened citizens’ confidence in the personal and societal abilities to make a difference, but also in the collective power of society to indeed tackle climate issues.
Why did this work? Participants rated the collective infographic significantly higher than the individual one in terms of presenting surprising information and conveying an appealing message. This may point to the persuasive power of the large-scale collective numbers used in the infographic. We argue using the language of ‘we’ may perform better in conveying the message that all gardeners are part of a community, sharing responsibility and impact.
The framing effects, however, were small and the effect of a one-time exposure should not be overestimated. To better understand the susceptibility of people to real-world policy communication, future research might adopt a collaborative field experiment approach.
Figure 2. Results for policy support and self-efficacy and outcome expectancy statements.
Source: Dewaelheyns, V. et al (2025). Notes: The results present the mean scores and error bars (SD) of (1) support for the four policy instruments (top, n = 3,389) and of (2) self-efficacy and outcome expectancy statements (bottom, n = 2,150). These are presented for the different treatment groups. For the policy instruments: control group (n =1,308), collective frame (n = 1,002), individually framed infographic (n = 1,069). For the self-efficacy and outcome expectancy statements: control group (n =801), collectively framed infographic (n = 646), individually framed infographic (n = 703).
The value of qualitative insights
The qualitative data substantially enriched our understandings of citizen support for depaving policies targeting private gardens, as well as of the reasons why the framed infographics were not effective for all four policy instruments. Citizens’ disbelief in control and enforcement on private paving for example is an aspect which was not addressed by the framed infographics and that may explain the lack of effect on a more stringent control and enforcement policy. The qualitative data indicates to policy makers that any policy on stricter permits for private paving should also include efforts towards a broadly accepted compliance culture.
Finally, the qualitative data confirmed that citizens are sensitive for policy interventions on garden paving, but simultaneously revealed that they also recognize their individual responsibility. Participants indicated a willingness to act, provided that any paving policy is perceived as fair and equitable, and that it also actively involves other stakeholders such as municipalities and companies (see Figure 3).
Figure 3: Ideas and feelings on depaving policies targeting private gardens, reflected by participants of the experiment
Source: Dewaelheyns, V. et al (2025). Notes: Scheme synthesizing the results of the open, axial, and selective coding of n = 847 comments. Two main insights relate to policy development on the one hand, and policy communication on the other hand. For policy development, participants believe ‘equity’ to be central, meaning that every stakeholder should (be motivated to) act responsible. Any policy measure should be context-specific and fair. Reflections upon the four tested instruments and ideas on additional instruments mentioned by participants indicates that instrument mixes are under discussion. Concerning policy communication, a pitfall using framing is the difficulty to communicate about the bigger, complex, picture. Positive formulations in terms of gaining something (e.g. greening) were suggested in stead of depaving, what feels like losing something. Finally, clear definitions of a garden and of paving are needed, as different interpretations emerged from the qualitative data.
Collective framing for effective climate communication
By comparing the effects on support for hard policies of collective versus individual framing in climate communication about private garden paving, we highlighted the importance of applying strategic message framing in climate communication design. We demonstrated how collectively framing the impact of small individual contributions can counter self-interest and increase support for necessary but often unpopular hard policy measures. This insight is especially valuable when building political and public support for effective and equitable climate adaptation measures especially in the private sphere.
For more details, you can read the full study here.
Valerie Dewaelheyns is a researcher at the KU Leuven Public Governance Institute, where she currently focuses on the behavioural potential for climate-friendly gardening policies. She holds a PhD in Bioscience Engineering from KU Leuven.
Pieter Raymaekers is a researcher and training coordinator at the KU Leuven Public Governance Institute. His research considers the use of evidence, behavioural insights and nudges in policymaking. He has a PhD in Modern History and a Master in Management from KU Leuven.
Florian Lange is a Research Manager and Senior Researcher at the KU Leuven Behavioural Economics and Engineering Group. His research revolves around the use of methods and insights from the behavioural sciences to promote (our understanding of) pro-environmental behaviour.
Ben Somers is a Professor at the KU Leuven division Forest, Nature and Landscape, Department of Earth and Environmental Sciences. His research uses remote sensing, GIS and in situ observations in spatial explicit modelling routines to assess and optimize ecosystem services delivery of urban green towards biodiversity, climate change and health.
Trui Steen is a Professor in public governance and coproduction of public services, and director of the Public Governance Institute at KU Leuven. She focuses, amongst other things, on co-creation and co-production of public services, collaborative innovation, and local governance.
This study was part of the interdisciplinary research project ‘GARLOCK: Unlocking the climate change adaptation and mitigation potential of the garden complex’, funded by KU Leuven, grant number C24M/21/015. The project joins forces of the Division Forest, Nature and Landscape, the Public Governance Institute, and Behavioural Economics and Engineering Group, KU Leuven.