IMAGE: Miljøpunkt Amager

Copenhagen pilots reduce up to 13%

of air pollution using environmental data

July 4, 2022


By Priscilla Castro

Officer, Communications and Member Relations, ICLEI Europe

Atmospheric pollution is a global threat that crosses continents, countries and local borders. Even in a leading green city such as Copenhagen, the high number of premature deaths caused by pollutants calls for urgent action. To strengthen the city's efforts on this front, non-profit organization Miljøpunkt Amager (MPA) harnessed environmental data, implementing pilots that reduced air pollution from fine particles by up to 13%.


Made possible by the ICLEI Action Fund (funding managed by ICLEI Local Governments for Sustainability and, the project used data from Google Air View and the Environmental Insights Explorer (EIE), bringing together experts from Gehl Architects, Studio Profondo, Danish Technological Institute and other partners. Named “Thrive Zone Amager (TZA)”, the project installed two domes in the Ørestad district and one green wall in Havnestaden/Islands Brygge as an alternative for citizens to spend more time outdoors while protected from air pollution."


Aimed at creating a model to test its impacts and understand local behaviour in specific areas of the city, the project relied on urban mobility, air quality and demographic data to create the interventions. “Managing air pollution in cities needs an integrated vision to protect human health and improve public spaces. Working with cities, civil society and local partners is critical, but data on air quality, population movement, car pollution and other components of daily life are also needed,” explained Alis-Daniela Torres, Climate Senior Officer at ICLEI Europe.

IMAGE: Priscilla Castro

The analysis process follows a technical approach. Sensors placed outside the installations capture the concentration of ultrafine particles and 2.5-micrometre matter particles (PM 2.5) in the air, while internal sensors calculate the indoor air. After the first month of data collection, the results showed significant reductions in air pollutants across the board.


The pilots began in August 2021, when TZA installed a wooden green wall between a high-traffic road and a residential area. On the left side, a single-column wall displayed different types of plants arranged scattered throughout the wood. On the right, a double wall with plants placed close together and fewer empty spaces for air to pass through. Beyond the wall, a playground was set up on a wooden platform to invite local families to use the space.


While the “thicker” wall registered a 3-5% decrease in PM 2.5 concentration between the air going from the road towards the playground, the real surprise came from the single wall - a 3% reduction in the pollutants. “Seeing this significant reduction

in a new wall with so many hollows between the plants, where the air had these areas of free passage is quite surprising. And the progression from thin to thick [wall] is also interesting. If we have an even thicker wall, we can expect even higher positive impacts,” explained Rasmus Reeh, an independent consultant and part of TZA’s experts’ team.


The project team considered several factors when evaluating the data, such as the impacts caused by the structure installed at the site. “Monitoring followed a dual perspective: firstly, the sensors on each side of the premises gave us insight into the direct difference in air quality. Secondly, since the facilities also influenced the general conditions by creating turbulence around the green wall, a baseline study should be carried out with and without the facilities present”, explained Rasmus Reeh.



IMAGE: Priscilla Castro

In the same month, the project team installed two domes made of polycarbonate: one with a 5-metre diameter between residential buildings and one with a 3.5-metre diameter next to a bus stop separated from the street by a green wall. The larger dome registered a 12% decrease in PM 2.5 concentration and 13% in ultrafine particles, while the smaller intervention showed that the air filtered by the green wall had a 4% decrease in pollutants even before reaching the dome.


The data in question are experimental and indicate that installations of this type can help to reduce the concentration of air pollutants, especially PM, in cities.


Impacts on health and well-being


According to the European Environment Agency (EEA), air pollution is the biggest environmental health risk in Europe. The World Health Organization (WHO) believes that prenatal exposure to high levels of air pollution is directly connected to anxiety, depression and delayed child development. In Copenhagen alone, about one in ten premature deaths can be attributed to the effects of air pollution.


Taking into account the negative impacts on human life, the interventions provided by the TZA prioritise the health and well-being of the population. Contributing to the local government's goals of reducing pollution and increasing the quality of life for citizens, the domes and the wall were thought of as spaces where residents can spend more time outdoors without exposing themselves to external factors such as atmospheric pollutants, strong winds, and rain, among others.


Therefore, the interventions were designed to be aesthetically pleasing and inviting. The frame-less dome-shaped structures, clad in translucent polycarbonate, proved to embed well into their urban environments, whilst the interior planting and furnishings, created comfortable and healthy indoor spaces. Flower pots and waxy, broadleaf, hairy, and perennial plants take care of the inviting climate while reducing the number of PMs in the air. In the larger dome, users can relax on cushions or beach chairs.


Hence, it’s not surprising that both domes attract the attention of passers-by. At first, people stop to take pictures or have a peek at the inside. Children are the ones who seem to enjoy the place the most. After seeing the new space from afar, two-year-old twins Gustav and Ania asked their nanny to take them closer. As they entered, they curiously explored the space and smiled.


IMAGE: Priscilla Castro

But more than just a pit stop, the dome has become a safe leisure space for the local residents. Some even plan to have a “weekend dome picnic” with the little ones. "I brought my three-year-old daughter and she loved it. I'm thinking of making some cupcakes and coming with her on a Saturday morning," said resident Pernille Qwist.


Like the domes, the green wall was designed to contribute to social sustainability and air quality improvement. Thirteen types of plants, such as Ivy (Hedera helix), geraniums, anemone and vincas, were selected for their air-purifying properties. Using timber as the primary construction material reduced the installation's carbon footprint, whilst also allowing for the flexible and modular replication of future structures and creating an inviting atmosphere where people like to stay.



IMAGE: Priscilla Castro

The public response was also positive. Berit Nielsen does not live in Copenhagen but usually goes to the city to visit her daughter and two-year-old grandson. “When I arrived, my daughter told me that there was something new in the area and that I should bring him here. I thought it was a great idea and I think it can serve as an example for other spaces. I hope this becomes permanent,” she said.


At first, the installations were planned to be temporary and run for one month but the analysis model and the public feedback led both domes to remain active. The bigger dome is still in the same position and is now been maintained by the joint secretariat of the landowners' associations and the Water Association in Ørestad (GFS Ørestad); while the smaller dome had to be moved as the permit was only temporary and is now placed in an allotment community.


The team considers the project a success. “The best-case scenario we expected was a reduction of between 10 and 20%, and that's what we got with the domes. If we think about these facilities in a larger and more specific way, we can have each one with a different configuration, other sizes, other types of ventilation. And that's the intention for the future: to scale and replicate the models in relevant locations, such as underground passages, sound barriers, etc. The project team is working to scale up testing the Thrive Zone toolbox,” concluded Rasmus Reeh.



IMAGE: Priscilla Castro

Listening to the community


Being invisible, untouchable and odourless, air quality is not the most common topic of conversation among friends. Although many are unaware of the term and its impact on human health and daily life, the community plays an important role in the implementation of environmental projects and actions. In this respect, TZA innovated by using a participatory process, raising awareness and engaging the local population.


The choice of location to implement the pilots was based on the results of an online survey carried out with the population of the islands of Brygge and Ørestad. Almost 800 participants answered a digital questionnaire about how they move around locally and how they use available urban spaces. The goal was to gather data on the role of urban spaces in people's daily lives and their influence on the priorities and challenges faced by the community.


More than half of survey respondents who live or work in Ørestad said they were concerned about air quality. When asked which item they most wanted in urban spaces, air quality came in second. At the same time, 49% of people responded that more green spaces would encourage them to spend more time outdoors. Residents of Ørestad still cited wind, hard surfaces and lack of city life as challenges.


In addition to contributing demographic data that facilitated project implementation, involving the community in the creation process was important to raise awareness of the topic. “We are very pleased with the great interest of the community in our project.

In all, nearly 1,000 citizens participated in our surveys, workshops and events, sharing their routines and problems with air quality. We are very proud,” said MPA Director Dorte Grastrup-Hansen.




To see the project’s journey since its inception, the designs used for its implementation and the impacts of the interventions in the public space, visit Miljøpunkt Amager’s website at:



For more information about the ICLEI Action Fund and other supported projects, visit:


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