Mehr als vier von fünf Wohnungen und Arbeitsplätzen in 25 europäischen Städten haben weniger Baumkronen in der Nähe, als für eine sinnvolle Kühlung erforderlich wäre. Nachbarschaften mit ausreichender Baumbedeckung und reifem Schatten sind deutlich kühler – um 4 bis 10 °C – als umliegende gepflasterte oder bebaute Gebiete.
https://www.eurekalert.org/news-releases/1134174
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More than four in five homes and workplaces across 25 European cities have less nearby tree canopy than what is needed for meaningful cooling, according to an open-data analysis by an urban greening expert.
Dr Thami Croeser from RMIT University in Australia has mapped tree canopy within 60 metres of 5.5 million buildings across France, Spain, Italy, Germany, Portugal, Greece and the UK.
His analysis found 84% of buildings fall below the 30% nearby canopy threshold identified in urban heat literature as important for reducing dangerous urban heat island effects.
Croeser, from the RMIT Centre for Urban Research, said Europe’s heatwaves are exposing a structural problem in the way cities have been designed.
„More than four in five homes and workplaces in the cities we analysed do not have the nearby tree canopy that urban heat research indicates is needed for meaningful cooling,“ he said.
„When severe heat hits, a leafy park three blocks away is too far away to help an apartment building surrounded by baking asphalt.“
Cologne and Hamburg performed best, with about 45% of buildings above the 30% threshold. Nice followed at 41%, largely due to hillside vegetation. After that, the picture deteriorates rapidly.
At the other end of the ranking, Sevilla, a city that regularly faces extreme summer heat, had 98% of buildings below the threshold.
Other city results include:
London: 93% of 1.5 million buildings below the threshold.
Paris: 96% of buildings below the threshold, with mean nearby tree canopy of just 12%.
Rome: 85% of buildings below the threshold.
Croeser said the scale of the deficit was not marginal. In most cities, more than half of all buildings had less than 10% canopy nearby.
„A city can appear to have a reasonable amount of tree cover overall, while most homes still have very little shade nearby,“ he said.
„Tree cooling is highly local. If canopy is not close to where people live and work, it is unlikely to protect them where they are actually experiencing the heat.“
https://www.nature.com/articles/s41467-026-70723-6
Makes sense, at least here in Spain we followed the American standards and built cities for cars rather than people. Only recently we’ve started to consider trees as more than just a means to pretty up a boulevard.
Drifting into a separate kind of science here, this is ultimately a (functionally) unfixable problem. Policies that improve the quality of life of humans tend to be very unpopular at times of austerity and reactionary politics.
As an American, If the Europeans end up tearing up unneeded roads to create forests and turn residential areas into lushly tree covered oases… I’m going to have something lovely to imagine when the jack-booted federal officers are crushing my head for sending an email to the DOJ saying Antifa isn’t a real organization.
4 to 10 degrees would be huge during heatwaves.
The local council floated planting trees on the street of one of my friends here in Belgium. One household went nuts about parking, and they dropped it instantly. We’d rather cook than lose a few parking spaces (and this is in a dense, walkable urban area with lots of public transport)
This study assumes that ’nearby‘ is within 60 meters of the building. Is there evidence that this is the appropriate distance?
Trees evaporate water which take heat away from the area, like doh.
Nashville would be a lot worse if it wasn’t covered in trees
My house is in the forest in SW France, and I can assure it was absolutely not 4C to 10C cooler during the last heatwave, it was just maybe 39 instead of 40 during the day and 26 instead of 27 during the night. Trees only help with preventing buildings and roads to build up too much heat during the day, so that you don’t get additional heat during the night in your appartment/house.
I’ve been on vacation in Europe for the last two weeks. Something I’ve noticed as an American is the often lack of trees and greenery on city streets in large cities. Yes you’ll have a lot of parks dotted around but nothing much around apartments and houses. Not until the country side. It’s been my experience in Germany, Austria, and elsewhere. Not to say I haven’t seen it, but the US there’s often trees lining the streets. Europe gets a lot of things better than the US including city design by a long shot. But having a shade trees to stop the streets and houses from baking makes a big difference.
Neighbors keep cutting trees down and no one bothers to replace them.
Brussels is brutal in the summer. There was no shade!
Unfortunately, there’s significant laws preventing tree canopies in many cities. Tree height is frequently regulated. see [https://romeroziegler.ch/wp-content/uploads/2025/04/Baeume-Straeucher-Nachbarrecht-Zuerich-Grenzabstaende-Kapprecht.pdf](https://romeroziegler.ch/wp-content/uploads/2025/04/Baeume-Straeucher-Nachbarrecht-Zuerich-Grenzabstaende-Kapprecht.pdf) (link in german but translates in auto-translators)
text: „• Smaller ornamental trees, dwarf fruit trees and shrubs must not be planted closer than 60 cm to the neighbour’s boundary. Up to a distance of 4 m from the boundary, these plants must be pruned so that their height never exceeds twice their distance from the boundary. At a distance of 60 cm, the plant may therefore be 1.20 m high; at a distance of 70 cm, for example, 1.40 m, and so on. “
It’s nearly impossible to have mature trees and a tree canopy with laws like this.
And it is not just trees; every plant evaporates water and contributes to cooling. Every shrub, perennial, ornamental gras.
I’m constantly shocked at how little greenery there is in European cities.