Trees cool cities and act as carbon sinks – but only if there is sufficient canopy cover in residential areas. Researchers’ canopy cover map shows the huge differences in tree cover in Espoo and Helsinki. Experience this and many other fascinating projects at the Designs for a Cooler Planet exhibition from 5 September to 28 October 2025!
Urbanization, climate change, and biodiversity loss are global challenges that demand urgent solutions. Greening cities—by preserving green infrastructure like trees —is a powerful way to enhance carbon sequestration, reduce urban flooding and heatwaves, and support the well-being of both people and other species.
But simply scattering greenery here and there isn’t enough. To deliver real local benefits, a sufficient amount of vegetation is needed. Aalto University’s canopy cover map shows that in some Helsinki neighborhoods, canopy cover reaches as high as 63%, while in others it drops to just 4%. According to the Co-Carbon project, neighborhoods with more than 25% canopy cover act as clear carbon sinks. Adequate canopy cover also ensures cooling benefits during heatwaves.
‘The maps clearly show that the climate benefits of urban greenery are not evenly distributed across Helsinki and the capital region—something policymakers should take seriously. When a city takes care of its trees, the trees take care of the people,’ says Ranja Hautamäki, Professor of landscape architecture at Aalto University.
The large canopy cover map on display at the exhibition allows you to examine the situation of Espoo and Helsinki at once. You can also explore separate canopy cover maps from our atlas, and get acquainted with the urban tree manifesto that complements the atlas!
Alongside the map, the exhibition also features the Carbon Tree, which visualizes the carbon cycle, and the Otaniemi arboretum project, all of which together tell the story of trees.
Place: Otaniemi campus, Otakaari 2
Open: monday-thursday 7:45-21:00, friday 7:45-20:00, saturday-sunday: closed
You can find more information about the exhibition here. Aalto University’s largest exhibition of the year showcases acts of change. Designs for a Cooler Planet is being held for the seventh time. The 2024 event reached over 10,000 visitors and featured nearly 20 exhibitions and over 30 events.
Photo: Ranja Hautamäki