What cities can do to prepare for heatwaves

A recent Sweco study predicts that European cities will experience an increase in both the number of heatwave days per year and the maximum temperatures during these events. These extreme heat events pose significant risks to public health, energy infrastructure and economic productivity in urban areas.

In the summer of 2022, Europe’s record-breaking heatwave resulted in 61,000 deaths, according to scientists. Despite these dangers, heat-related health concerns are often overlooked in climate mitigation and adaptation plans. Additionally, significant heat disparities within urban centres disproportionately affect vulnerable and marginalized communities.

“European cities’ climate plans need to focus more on protecting vulnerable groups by improving the cooling of facilities such as preschools, assisted living facilities and care homes. EUR 680 billion of the EU’s budget is allocated for climate-relevant measures during the 2021–2027 period, so there is funding available. It is now time for European cities to level up by implementing new methods that help cool cities,” says Séverine Hermand, climate resilience planning expert at Sweco.

Below is a list of recommendations for European cities as they try to prepare for the rising number of heatwaves.

Invest in knowledge-building

Set long-term visions and short-term actions: Set long-term goals for heat resilience, aiming towards 2100, and then work backward to trace the steps needed to achieve those goals. This helps clarify the necessary goals and actions for the medium and the short term.

Make action plans and set priorities: For policymakers and urban practitioners, it is imperative to prioritise the development of comprehensive heatwave response strategies. These strategies should be informed by robust empirical evidence and grounded in principles of climate equality, like accessibility and fair distribution of resources.

Test, monitor, assess and adjust: Approach heat management in the same proactive manner as water management – through testing, adaptation and modulation. When implementing blue-green solutions to combat heat, it is crucial to conduct thorough testing and follow-up assessments to ensure that these solutions effectively meet the needs of the community and make the desired positive impact.

Innovate and optimise

AI, digital twins and IoT

Develop advanced AI algorithms to predict and monitor heatwaves, allowing for early warnings and proactive planning.
Implement smart infrastructure solutions, such as intelligent cooling systems and energy-efficient designs, to reduce the urban heat island effect and provide cooling in high-risk areas.
Utilise digital twins of cities or specific regions to simulate and optimize urban planning strategies, including the placement of green spaces, shading structures, and cooling measures.
Incorporate IoT sensors and data analytics to gather real-time information on temperature, humidity, and air quality, enabling targeted interventions and resource allocation during heatwaves.
Enable and optimise the use of renewable energy sources and energy-efficient technologies to reduce heat-related energy consumption and greenhouse gas emissions.

Develop ecological networks and cooling corridors

Develop urban cooling corridors: Create visions and plans to configure networks of open spaces at the city level, reinforcing existing landscape and green-blue structures, connecting the missing links and providing the framework to incrementally create cooling corridors at the city level that have high ecological value.
Create multifunctional open spaces: Many blue-green solutions can effectively manage both stormwater and heat. These solutions optimise land use efficiency and prioritise biodiversity and social sustainability.
Optimise building orientation: The orientation of buildings towards the outdoor environment is vital. Buildings can serve as a significant component of shading functionality.

Upgrade systems and networks with nature-based solutions

Develop nature-based solutions: Improve existing mobility infrastructure through nature-based solutions. These are actions that protect, sustainably manage and restore natural or modified ecosystems in order to address societal challenges effectively and adaptively while providing human well-being and biodiversity benefits.
Define the role and goal of greenery: Set specific objectives and desired outcomes that greenery should achieve in the project, like improving air quality or providing recreational spaces by selecting appropriate plant species and implementing green infrastructure techniques, for instance. Identify the critical factors and requirements necessary for a successful implementation, such as site conditions and collaboration with stakeholders.
Optimise paved surfaces: Another multifunctional approach involves integrating heating adaptation with mobility strategies in cities. By reducing space for cars through measures like reducing lanes and implementing one-way streets, more space becomes available for greenery.

Increase building performance

Design high-performance buildings with advanced technology to remain functional even in extreme heat. Incorporate effective ventilation and cooling systems during construction. Engage with users to understand their needs. Consider ceiling height, awnings, blinds and operable windows to mitigate solar radiation and heat buildup.
Redesign building regulations: In the Nordic countries, today’s building regulations are designed to keep heat inside and cold outside. However, in light of the increasingly warmer climate, we need to rethink these regulations.

Co-create

Establish heatwave governance: Cities need to create crisis teams dedicated to managing heatwaves, mirroring the approach taken for heavy rainfall and floods.

Set cooperation frameworks: City networks offer significant benefits for climate adaptation and resilience. They facilitate city-to-city learning through the sharing of best practices and increase access to funding opportunities.

Raise awareness and involvement: Enhance public awareness, education and participation, cities can harness local knowledge, resources and creativity to develop more effective and inclusive climate adaptation measures.

Extend heatwave mapping: Mapping vulnerable groups in relation to heatwaves is crucial. In addition to geographic information systems (GIS), alternative data gathering methods such as citizen science can be leveraged. Citizen science provides precise data on fine-grained contexts and helps raise awareness and foster community engagement.

Co-create: Engage intended users in the design process. For instance, educators should be consulted when designing a preschool playground. It’s crucial to designate responsibility for playground upkeep upfront. Besides greenery, immediate shade solutions like pergolas or sunshades are vital, especially since newly planted trees take years to mature.

Empower communities: Proactive measures are crucial in helping vulnerable populations cope with extreme heat. Cities and organisations can engage with these groups to implement strategies, such as setting up cooling centres, providing multilingual heat safety information and offering assistance with utility bills or access to air conditioning units during heatwaves.