Ready for the heat island?

How do you imagine a climate-resilient city? In order to understand the answers, we first have to move closer together. Cars whizz past, a siren of an emergency vehicle wails in the immediate vicinity. "Without cars," replies one of the Climate Walk participants spontaneously, "but with water and lots of green spaces that are accessible to everyone".

Around 20 people have gathered today at Maria-Theresien-Platz square in the 1st Viennese district for a joint Climate Walk to explore Vienna on foot and find out how our city is preparing for climate change. Expert input is provided by the University of Vienna's urban psychologist Addi Wala, Eva Braxenthaler, a member of the Grätzloase project, which aims at creating liveable districts, and Matthias Ratheiser, who founded "Weatherpark" after studying meteorology at the University of Vienna and has been a consulter for urban climate ever since (here you can read more on his founding story in German).

Urban heat islands

The summers in Vienna are one thing above all: hot. And they are becoming even hotter. In the 1970s, Austria had seven hot days per year on average. Today, we have 27 - and the number is rising. "Urban areas heat up more than their surrounding areas," explains urban researcher Kerstin Krellenberg from the University of Vienna, "in the city we have more sealed surfaces and a lot of heat-storing material such as asphalt, concrete, metal and glass. Buildings and streets absorb solar radiation, store the energy and release the heat back into the environment, thus creating so-called urban heat islands, which can be up to ten degrees warmer than the surrounding countryside."

When the heat becomes a problem

Krellenberg is working at the Department of Geography and Regional Research on the effects of increasing heat. She is cooperating with various urban stakeholders from politics, administration, the private sector and civil society. Vienna is thus becoming an urban laboratory where experiments are carried out together and locals are given a voice to develop innovative solutions for our cities. The heat is becoming a problem, especially for those who live in densely built-up areas and in insufficiently insulated buildings or have no cooling green spaces in their neighbourhoods, "but in principle for everyone who encounters asphalt and concrete without shade in public spaces," says Krellenberg.

The Climate Walk group has reached Lerchenfelder Strasse street in the meanwhile. Concrete and asphalt blaze in the heat, participants gather around the public drinking fountain and fill their water bottles. They listen to urban psychologist Addi Walla from "STADTpsychologie", who is working on a City of Vienna project to change Lerchenfelder Strasse street. "The aim is to redesign the street as part of a participatory process. Among other things, residents want more trees, lots of greenery and traffic calming." People and the environment are often mistakenly seen as opposites, but urban and environmental psychology are interested in the interplay between the two. "After all, a city does not just consist of buildings and streets. What really defines it are the people who live in it," adds Walla.

"Shade is for the rich"

The city walk through Vienna is a joint initiative of the Environment and Climate Research Hub (ECH) of the University of Vienna and the Climate Walk Austria association, whose members have already walked across Europe to raise awareness of the climate crisis and to engage in dialogue with local stakeholders. "Someone in Brussels once told us that 'shade is for the rich'", remembers Eva Holzinger from Climate Walk Austria. What is the situation in Vienna? Who is "allowed" to live in the shade?

Urban geographer Yvonne Franz from the University of Vienna, who specialises in cooperative urban development in Vienna, provides the answer. "The Gürtel beltway was originally a dividing line between privileged residential areas in the city centre and neighbourhoods in the historic suburbs of Vienna, where socio-economically disadvantaged people lived. This has changed in recent years," says Franz. "Vienna's districts are now closely connected and the city is initiating many development projects. For example, a high-quality open space was created on the forecourt of the Westbahnhof railway station together with an international furniture company – now there are wildflowers, trees and seating. But what we do not immediately see is the displacement of marginalised groups through gentrification, i.e. the process of transforming a neighbourhood from low value to high value. For example, what about people who are homeless and spend their leisure time outdoors? They are often not wanted in the newly created cooling zones. There is no room for them there any longer."

Sensing the city on the Climate Walk

The walk through the city sharpens our senses: We experience how different building materials feel, how green spaces and trees cool the city, how targeted cooling measures change the perception of heat and that we are still far away from climate justice. Summer is the best time for a Climate Walk: Join Yvonne Franz and Kerstin Krellenberg on 8 August 2024 on a walk across Vienna (in German) or head out on your own. (hm)