How should Pinneberg deal with heat and heavy rain?

On September 11, 2026, a Citizens' Jury on climate adaptation began its work in Pinneberg. Thirty randomly selected citizens will discuss how their city should deal with heat, heavy rain and other consequences of climate change. What makes the process unusual is that some of their proposals could later be put to all eligible voters in a referendum.

Pinneberg has a problem

Pinneberg has a problem that almost every German city now knows. When temperatures rise, streets and buildings heat up. When heavy rain falls, the water has to go somewhere. More greenery, unsealed surfaces, green roofs and façades, or the principle of the sponge city can help. But all of this costs money – and, above all, space. Where an area is used to absorb rainwater, it may no longer be available as a road, parking space or building plot.

30 residents of Pinneberg will discuss precisely these conflicts. The Citizens’ Jury on climate adaptation will meet on 11 and 12 September and again on 25 and 26 September. Experts will first provide information, after which the randomly selected participants will deliberate with one another and formulate recommendations. The question is no longer whether Pinneberg must adapt to the consequences of climate change. The question is how – and what the city is prepared to change in order to do so.

A “Miniature Pinneberg”

The 30 members were not elected, nor were they simply able to register themselves. At the end of April, the city wrote to 1,500 residents randomly selected from the population register. 154 agreed to take part. From this group, a further selection was then made so that the assembly would resemble the city as closely as possible in terms of age, gender, educational background and migration history.

Mayor Thomas Voerste calls the result a “miniature Pinneberg”. He says the composition provides a good basis for developing “viable proposals for climate adaptation in Pinneberg”. At the same time, he associates the process with a democratic hope: “The entire process can strengthen the democratic process in our society.”

Natalina di Racca-Boenigk, chairwoman of the city council, describes the idea even more vividly. In the Citizens’ Jury, she says, “a lawyer may sit next to a hairdresser, or a trans person next to a conservative” – people who might never otherwise have entered into conversation with one another in everyday life. She sees precisely this as the strength of the process. Participants should not argue along political dividing lines, but work together in search of solutions: “That is democracy in practice.”

Climate adaptation begins on the ground

What the 30 participants will discuss may initially sound technical. But Milan Bogojević of Pinneberg’s Urban Development and Climate Office makes clear how quickly climate adaptation becomes a question of distribution. Many measures are structural and cost money, he says – money “that municipalities hardly have today”. On top of that come competing demands on public space.

One example is the removal of sealed surfaces. Asphalted or paved areas can absorb hardly any rainwater. If they are unsealed, water can seep into the ground, be retained during heavy rain and later evaporate again through plants and soil. But an unsealed area may then no longer be available for a road or another use. That, Bogojević says, is exactly when resistance from individual groups begins.

Pinneberg is already experimenting with some measures. In one construction project, the city is using elements of the sponge-city principle: rainwater is not simply channelled into the sewer system, but stored in green spaces, where it can evaporate and at the same time help cool the surroundings. There are also green roofs and façades, a drinking-water fountain and a map showing cool places where people can seek refuge during periods of extreme heat. Private individuals can also do something, says Bogojević – for example by “doing without a gravel garden” and planting greenery instead.

From Citizens’ Jury to referendum

The real democratic experiment, however, begins only after the four days of meetings. The Citizens’ Jury is to summarize its recommendations in a citizens’ report and submit it to the city council. Politicians and the administration will then assess the recommendations from a professional perspective. The city council will decide which proposals it wants to take up itself – and whether individual questions are suitable for a referendum.

According to the current timetable, such a referendum could take place together with the Schleswig-Holstein state election on 18 April 2027. Unlike the recommendations of the mini public, the result of the referendum would be binding. The deliberations of 30 randomly selected people could thus lead to a decision by all eligible voters in Pinneberg.

This is the core of the model project “Klima trifft Kommune” (“Climate Meets Municipality”), organized by Mehr Demokratie and the Gesellschaft für Klima und Demokratie (Society for Climate and Democracy). Alongside Pinneberg, Flensburg, Osterburg in Saxony-Anhalt and Marzahn-Nord in Berlin are taking part. The processes combine deliberation by randomly selected citizens with a subsequent political or public decision on the recommendations.

The question of binding decisions

Steffen Krenzer, project manager of “Klima trifft Kommune”, sees precisely this combination as a response to a weakness of many participation processes. “Climate adaptation measures affect the entire population,” he says. Involving people at an early stage can not only produce better solutions, but also make it possible to adopt them in a binding way afterwards. “Participation creates legitimacy and makes implementation easier.” Difficult questions in particular, such as conflicts over the use of scarce space, can be addressed in this way.

Pinneberg therefore touches on an old debate surrounding mini publics: what happens to their recommendations? Randomly selected citizens can spend weeks or months becoming informed and deliberating – but if their proposals are merely received afterwards, disappointment can follow. In Pinneberg, the intention is therefore to establish from the outset what happens next: citizens’ report, professional assessment, city council, and possibly a referendum.

A recommendation will not automatically become a referendum question, however. The city council retains a decisive role. It will decide whether and which recommendations are put to the public vote. The Citizens’ Jury therefore gains considerable influence over the political agenda, but not the final decision over what appears on the ballot paper.

A decision with a history

Pinneberg’s decision to follow this path was by no means politically self-evident. On 10 October 2024, the city council voted 23 to 16 in favour of taking part in the model project. The process had originally been intended to take place considerably earlier; the timetable was later postponed. In the meantime, what began as a broader field covering both climate protection and climate adaptation has become a Citizens’ Jury focused explicitly on adapting to the already perceptible consequences of climate change.

Voerste had described the mini public early on as an opportunity to involve local people more closely in decision-making. Climate targets could only be achieved, he said, “if we bring citizens along with us as effectively as possible”. The Citizens’ Jury could be “an important building block” in that process.

There is a certain political shrewdness in concentrating on climate adaptation. Abstract emissions targets can easily become the subject of fundamental political dispute. An overheated square, a flooded basement or a tree providing shade make climate policy tangible. Yet the conflicts do not disappear. Anyone who unseals land, changes parking spaces, redesigns streets or spends money on greenery is redistributing scarce resources.

Thirty people and a rather large question

Bogojević therefore sees the process as more than a method for collecting ideas. Many people are dissatisfied with the outcomes of parliamentary democracy, he says, and particularly on controversial questions there are doubts over whether politics is choosing the right measures. If citizens are first given comprehensive information and then deliberate on measures themselves, this has “a different effect than when politics alone makes the decision”.

Whether that hope will be fulfilled remains to be seen. The 30 residents of Pinneberg must first spend four days listening, asking questions, disagreeing and finding compromises. Afterwards, the city council will have to show how seriously it takes the results. And finally, in April 2027, all eligible voters may get to decide.

Perhaps that is precisely what makes this small experiment on the outskirts of Hamburg interesting. Climate adaptation is often treated as a matter for engineers, urban planners or environmental experts. In Pinneberg, for two weekends in September, it becomes a question for citizens: What should a city look like in which people can continue to live well despite more heat and heavy rain – and what are they prepared to change in order to achieve that?