Zurich: Hotspot Switzerland

In 2022, The Economist ranked Zurich as the third most liveable city in the world. The Swiss metropolis also continues to make a name for itself in architecture and landscape architecture. Most recently through its exemplary approach to the issue of heat. An overview of the measures and projects in the canton and city and why they are still subject to criticism.

The city of Zurich has developed a comprehensive climate adaptation program to reduce heat with the Implementation Agenda 2020-2023. The aim of this program is to find solutions to combat overheating in the city in order to maintain the quality of life and protect the health of residents. To this end, several city departments worked together on this program, which has three main objectives: To prevent overheating throughout the city, to provide targeted relief for vulnerable urban areas and to preserve the city’s existing cold air system.

The agenda serves as a guideline for the implementation of various urban and open space planning projects. It clarifies the obligations and provides a comprehensive overview of the objectives, principles, costs and financing. A catalog of measures is available to the administration, planners and builders and uses fields of action, approaches and modeling areas to show what climate adaptation can look like in concrete terms and what effects it has.

1. Heat reduction: Climate maps and analyses show the heat load in urban areas. Depending on the urban structure, the right mix of measures is found, with different approaches for day and night.
2. Relief systems: This sub-plan distinguishes between dense areas and areas with sensitive uses, such as schools or retirement centers. New green spaces are created and existing ones upgraded. A climate-optimized network of paths connects the green spaces.
3. Cold air system: The third sub-plan ensures night-time cooling by maintaining and optimizing cold air flows.

Based on climate analysis maps, the Air, Climate and Radiation Department of the Office for Waste, Water, Energy and Air has developed an additional planning tool. Building owners, developers and specialist planners can use it to view information on measures and integrate them into their planning. The “Heat in urban areas” tool suggests measures such as green roofs and façades, shading of streets and surfaces, rainwater retention and storage as well as the implementation of water surfaces or unsealing.

The “Heat in urban areas” website complements this planning tool. Here, planners can find comprehensive information and examples from the canton of Zurich that illustrate the benefits of the measures. The website proposes measures for urban planning, buildings and open spaces in order to sustainably improve the climatic conditions in urban areas.

In the “Bahnhof Nord” development area, the pioneering Zwhatt project is transforming the area as part of the “Adaptation to climate change” pilot program. Zwhatt aims for a low-car zone, relies on public transport and bicycle parking spaces and uses renewable energy through photovoltaic systems and groundwater. A central promenade ensures cold air circulation and rows of trees provide the necessary shade. The project requires a high level of coordination and regular communication between all parties involved. Conflicts such as noise protection versus ventilation are critically considered.

In 2021, the city planted additional trees on Turbinenplatz in the Escher-Wyss-Areal to reduce the summer heat. Since 2022, an aluminum ring with fog nozzles has been helping in the short term, spraying fine mist at temperatures above 30 degrees and making the square up to ten degrees cooler. The “Alto Zürrus” pilot project runs until fall 2024 and collects data on air quality and temperature.

An exhibition in the city nursery showed how plants, water, shade and light surfaces can help keep temperatures cooler. The great importance of green spaces, trees and cold air currents was impressively illustrated. Visitors were able to discover solutions to combat global warming at various stations.

Zurich is actively tackling the summer heat with new strategies and measures. Despite criticism of delayed action, the city is focusing on innovative solutions and remains a leading metropolis in heat reduction. The coming years will show how effective the measures are and what lessons can be learned from them.

With its climate adaptation program for heat mitigation, the city of Zurich has developed a comprehensive strategy to cope with the effects of climate change. The various measures and projects are intended to safeguard the quality of life of residents and make the city more resilient to heat. The success of these measures will become apparent in the coming years and will serve as a model for other cities.