Refreshing Strasbourg to improve quality of life and protect people

With approximately 300 000 inhabitants spread over 80 km², the City of Strasbourg is the most populated city of its region, the Strasbourg-Ortenau Eurodistrict, organised around the Rhine River. Usually known for its semi-continental climate, Strasbourg is now facing a massive rise in temperature, with consequences all over the territory, indistinctly impacting populations, ecosystems and infrastructures.  

With peaks reaching nearly 40°C in 2019 and 2022, as well as an increase in the intensity, frequency and duration of heatwaves, Strasbourg must urgently address heatwaves, especially considering they are aggravated by the urban heat island effect. 

A wide-ranging action plan to strengthen the protection of populations 

The City of Strasbourg is taking action to address heat by implementing a set of cross-cutting measures to better prevent heat-related risks. Every year, the city services put in place a heat risk prevention plan during the seasonal heatwave alert period, from June 1^st to September 15^th. These measures are the result of a partnership initiative launched in the wake of the 2003 heatwave. 

Strasbourg firmly believes that adaptation to climate change can only be optimised when it combines all types of solutions known to date: nature-based solutions (green and blue), urban solutions and behavioural solutions. Furthermore, they believe that climate change adaptation must result in an improvement of quality of life for all and a greater protection for the most impacted and vulnerable people. 

^{Strasbourg's street (after/before) © City of Strasbourg} 

Combating heat and improving quality of life 

The city is investing heavily in soil unsealing and greening of public spaces. The Canopy Plan provides for the planting of 1 000 trees (net) each year from 2020 to 2030, in order to contribute to the goal of reaching a 30% canopy index across the territory by 2050.  

Water also plays a major cooling role, which is why the local authority is installing temporary fountains and water points, while improving access to urban swimming facilities during hot periods. Particular attention is being paid to priority neighbourhoods within the city, to reduce the gap regarding access to cooler and greener areas.  

The city also makes a point of increasing the co-benefits of implemented measures as much as possible. For example, the greening of 60 schools – with about 500 trees planted and over 40 000 m² of soil unsealed – has been the opportunity to address gender inequities in schools. By redesigning schoolyards, the city is putting an end to its former unbalanced gender use. 

^{Redesign and greening of a school courtyard (before/after)- © City of Strasbourg}

Furthermore, by considering summer comfort and using bio-based materials in energy renovations, the city also aims to improve thermal comfort for those living or working in community buildings. 

Combating heat and protecting vulnerable groups 

Nature-based and technical solutions, although essential, are sometimes not enough to protect the most vulnerable in the case of a heatwave. Hence the need for a specific Heatwave Plan, focusing on the following actions:  

• Mapping public spaces offering cool respite (urban cooling islands, parks, ice rinks, lakes, swimming pools, public toilets, fountains), as well as indoor shelters (pharmacies, community centres, places of worship, museums, etc.). Taking inspiration from the Lyon Metropolis, the city is also working on the creation of a mapping tool offering alternative routes to the ‘fastest route’, based on the coolness of the routes (shade from buildings at different times of the day, vegetation, presence of water, infrastructure along the route facilitating the movement of elderly or disabled people).

^{Strasbourg's fresh map - © City of Strasbourg}

• An internal alert unit, bringing together the departments affected by the rise in temperatures, according to four levels of severity.
• An information campaign to inform the population of best practices to adopt in the event of high temperatures.
• Establishment of a monitoring unit by registering people who are highly isolated and whose condition is aggravated by heat waves (mainly, elderly and disabled people). If calls from the monitoring unit are sufficient for some people, for others it may be necessary to visit their homes to assess their physical and psychological state, and to take adequate measures if needed. A psychologist also remains available. 

Main challenges to address heatwaves

• The distribution of all information and tools to the population is a major challenge of the Heatwave Plan.
• The municipality still lacks measurements and feedback regarding the cooling solutions it has deployed, to better assess their respective impacts.
• We still need to tackle more the impacts of heat on networks (energy, communication, water) and more generally infrastructures. 

Lessons learnt and next steps

• Implications for stakeholders: The involvement of associations, residents and socio-economic stakeholders in the area is a key factor for success.
• Diversity of actions: Protecting populations requires the implementation of a wide range of solutions tailored to the local context and target audience.
• Strengthen risk awareness: Knowledge of the risks and means of action is crucial in ensuring that people understand the issues and implement the necessary measures.
• Integrating 2050 climate: Furthermore, although the city knows that it is helping to protect people from heat through its various actions, we still need to work on integrating the climate of 2050, not today's climate, into fighting the impacts of heat in Strasbourg. 

Replicability

Nature-based solutions and community resilience are the two main drivers of our current policies regarding the protection of population during heatwaves, by presenting the biggest co-benefits and being considered ‘no regrets’ whatever climate pathway occurs in the future.  

Strasbourg's Refresh

Solutions to address heatwaves: 4 types

Maximum temperature reached during extreme heat events: 38.9°C in 2019, 45 consecutive days above 25°C in 2022 

• Nature
• Urban Design and Technology
• Community Driven
• Governance
  • Greening, soil unsealing, shading infrastructures, water cycle, urban design, community resilience.  

Expected results with the solutions implemented:  

• Protect populations
• Protect and enrich ecosystems
• Involve local actors in the fight against the negative effects of the rise in temperature   

Covenant Figures 

Signatory to the Covenant of Mayors since: 2020

Emission reduction ambitions:  

• Overall CO2 emission reduction target:
• % GHG emissions reductions by 2030: -55% compared to 1990
• % GHG emissions reductions by 2050: Contribution to national 'Net Zero'

City Awards

• Green Capital 2024
• EU Mission on Adaptation to Climate Change

Related links

• Link to the Heatwave Plan (French)
• Open access mapping of urban cool islands (French)
• Analysis of spatial and temporal variability of urban heat island in Strasbourg (French)