- Story
The path to climate resilience in cities and rural areas
08.10.2026 Hot, dry summers, more frequent heavy rainfall: Switzerland is facing the impact of climate change. Professor Jerylee Wilkes-Allemann, a forest scientist at BFH-HAFL, explains how urban and landscape planning can respond to this challenge.
Key points at a glance
- Lots of asphalt, little shade: Swiss cities have become more vulnerable to summer heat and struggle to drain away increasingly heavy rainfall.
- Climate adaptation is a collective effort that calls upon architecture, landscape and urban planning, as well as forestry.
- In the coming weeks, two BFH events will offer deeper insights into this topic to both experts and the general public.
Let’s take a look at the future: Which effects of climate change will have the greatest impact on people’s lives in Switzerland?
Swiss climate scenarios predict higher temperatures, drier summers and more frequent heavy rainfall. The heat will be felt most acutely in populated urban areas, e.g. in people’s homes, on the way to work and in public spaces. Meanwhile, prolonged drought is placing a strain on trees, forests and the agricultural sector. Heavy rainfall is also posing new challenges for settlements. We should therefore consider these developments in a coordinated way and plan solutions holistically. To thrive, a tree needs water, enough space for its root system and canopy, and permeable soil, which also helps absorb excess rainfall.
Our cities were designed for the climate of the 20th century. In what areas are they reaching their limits today?
These limitations are especially evident in densely built neighbourhoods with large areas of asphalt, insufficient shade and little space for tree roots. On average, trees are given 12 cubic metres of space for their roots. But a large tree actually needs between 200 and 300 cubic metres of root space. At the same time, utility lines, traffic, parking lots and green areas are competing for limited street space. The challenge, therefore, is not simply to plant more trees. We must create the conditions under which they can grow and provide their ecosystem services for decades to come.
About
Prof. Dr Jerylee Wilkes-Allemann is a lecturer in forest and environmental policy at BFH’s School of Agricultural, Forest and Food Sciences HAFL. In her research and consulting activities, she focusses in particular on climate adaptation and the role that trees and forests play in supporting it. “Research can help municipalities identify where action is needed, develop appropriate measures and involve the relevant stakeholders. A heat stress map alone is not enough for this. It is crucial to understand who uses an area, where trees can be planted, who is most affected by heat and who will look after the green spaces in the future,” she stresses.
More recently, Jerylee Wilkes-Allemann and her team developed a concept for the City of Villeneuve (VD) to support climate adaptation and expand its urban tree canopy. Implementation is set to take place in the coming years. Researchers are also investigating which Swiss municipalities could benefit from mobile greening, especially in densely sealed and heat-affected areas where trees cannot be planted permanently.
By 2050, how will we recognise that Swiss cities and landscapes have adapted to climate change?
By then, I hope that we will see and feel the change by taking a walk through a neighbourhood. Streets and squares will provide shade even on hot days, rainwater will be absorbed by the ground and there will be enough room for trees to thrive. Green façades will be part of the cityscape, diverse habitats will enhance biodiversity and there will be significantly fewer sealed surfaces. We will live more in harmony with nature.
What does that mean in practical terms?
The 3-30-300 rule provides a useful benchmark: At least three trees should be visible from every home, school and workplace. At least 30 percent of every neighbourhood should be covered by tree canopies, and the nearest public green space should be no more than 300 metres away. For me, it is especially important that neighbourhoods currently lacking trees and green spaces become greener.
What about the situation outside our cities?
We will see the transition to robust and resilient forests and landscapes, which will provide habitats, retain water and remain accessible to people. Forest and spatial planning will be working more closely together, shaping places where people can thrive, even as climate conditions continue to change.
Is it time to fundamentally rethink our idea of urban development and the landscape?
I believe so. We should view trees and green spaces as an essential part of urban development and plan cities and their surrounding areas in a coordinated manner. Individual trees, tree-lined avenues, parks and peri-urban forests provide shade and cool the air, delivering a wide range of ecosystem services. At the same time, they provide habitats and spaces for physical activity, social interaction and recreation. In my research, I am particularly interested in how these diverse services can be preserved in the long term and who will be responsible for safeguarding them. Climate adaptation is a collective effort. Architecture, landscape and urban planning, forestry and other disciplines must engage in continuous dialogue, make joint decisions and collectively shape the development of tomorrow’s cities. This transformation will not happen overnight. We, or at least I, probably will not enjoy any of the things we are planning today, but our children and future generations will.
Thematic events
Two upcoming events at BFH will address the topic of climate adaptation:
The next event in the ‘Impact & Connect: a meeting point for sustainable development and innovation’ series takes place on 22 October 2026 under the theme: ‘From heatwaves to torrential rain: How can we protect ourselves in the face of the climate crisis?’ Jerylee Wilkes-Allemann and BFH alumni will offer insights into their work in the field of climate adaptation.
On 23 and 24 November 2026, the conference ‘Green the City – Grow the Future: How can we make cities greener, more liveable and truly sustainable?’ will bring together experts from research, business and the field to discuss current developments, approaches and experiences.
If you could offer just one piece of advice to decision-makers in Swiss municipalities, what would it be?
To protect and preserve existing trees and green spaces while creating room for more. And to consider climate adaptation and green spaces from the outset, in every upcoming redesign project, involving those who use and manage the area. Don’t just ask where there is room for a tree today, but what it will take for it to thrive in 20, 40 or 80 years. Include existing trees and green spaces in the planning process early on, rather than removing them during construction and looking for replacements afterward. Climate adaptation requires forward-looking planning, long-term responsibility and a shared vision of how we want to live in the future.
Is there a particular landscape, project or city that gives you hope for the future?
For me, the redesign of the Optingenstrasse in Bern is an inspiring example. Space for trees was created in the neighbourhood, and part of the asphalt was removed. This project shows that climate adaptation can take very tangible forms, starting with a street that people use every day. Such changes also show that a tree is more than just a decoration: it is a key element of a resilient, sustainable and high-quality public environment.
