Swiss Review 3/2020

Swiss Review / June 2020 / No.3 7 AcclimataSion six years ago in order to adapt urban development as well as building regulations more effec- tively to climate change. As city plan- ner Lionel Tudisco puts it, the aim was “green and blue in place of grey”. This involved planting more trees in public spaces. “A tree has the same cooling effect as five air-conditioning units,” Tudisco explains. In the day- time, it can be up to seven degrees cooler where trees cast shade than in the immediate vicinity. Waterways, fountains, lakes and ditches are the ‘blue’ helping to irrigate the city. “These features create microclimates and reduce temperature fluctua- tions,” he says. The objective is not only to lessen the urban heat but also to mitigate the impact of floods. This is because climate change also leads to more frequent heavy rains in addi- tion to higher temperatures – the vi- olent thunderstorm that caused flash floods on Sion’s lower-lying roads in August 2018 being a case in point. The landscaped Cours Roger Bon- vin is the showcase feature of the Ac- climataSion project. This 500-metre­ long pedestrian promenade situated on the roof of a motorway tunnel used to be a rather uninviting con- crete heat trap. Today, some 700 trees provide welcome shade in a public space dottedwith islands of greenery. An artificial beach and generous seat- ing and lounging areas create a holi- day vibe as kids splash around in a specially constructed paddling pool. Mapping the urban climate Larger urban areas in Switzerland are also having to contend with climate change. Officials in Zurich want to take action – they expect a twofold An artificial beach, a paddling pool and green islands dot the asphalt – AcclimataSion is a pio- neering project in the Valais capital of Sion. Photos: Flurin Bertschinger