"Impact of Urban Heat: Could European cities become uninhabitable due to soaring temperatures?"
European cities are taking bold steps to combat the urban heat island (UHI) effect, a phenomenon that raises temperatures in urban areas compared to surrounding rural regions, intensifying heatwaves. The UHI effect is primarily caused by the materials used in cities, such as asphalt and cement, which absorb and retain heat.
The City of Brussels, particularly vulnerable to heatwaves with temperature differences up to 10°C compared to rural surroundings, is at the forefront of this battle. The local government is providing residents with interactive maps highlighting locations of drinking water points, shaded green spaces, museums, and fountains to offer relief from heat during extreme events.
The emphasis in Brussels is on green and water-based urban interventions to reduce heat exposure. The City is committed to physically adapting and improving its living environment by planting trees, softening surfaces, making squares and streets shadier and greener, bringing water into the city, and creating green-blue networks.
Across Europe, cities are adopting integrated approaches combining technical infrastructure, nature-based solutions, urban planning, and community engagement to both mitigate and adapt to the increasing challenge of urban heat islands intensified by climate change.
Key strategies include increasing urban greenery, improving water features and urban blue-green spaces, urban design for ventilation, decarbonized district cooling systems, and public information and adaptation policies. For instance, cities like Barcelona, Vienna, and Munich have implemented centralized thermal energy supply using renewable and recovered energy sources to provide energy-efficient cooling while reducing emissions.
Experts stress the importance of redesigning cities to reduce concrete surfaces and enhance vegetation, aiming to diminish the intensity of the UHI effect as part of broader climate adaptation. However, they warn that adaptation alone is not enough to counteract the urban heat island effect, and mitigation must also be a priority.
If CO2 emissions are not reduced to zero, experts warn that "a tsunami of heat" will descend onto cities, which could become unlivable. Therefore, cities like Brussels are also focusing on sustainable renovations of buildings, which account for 60% of CO2 emissions in the region, as well as sustainable plans for mobility and energy.
It's important to note that traffic in a city can also impact the urban heat island effect, as pollution from cars can act as a greenhouse gas layer, trapping hot air. The summer of 2025 has been marked by several successive heatwaves across Europe, with surface temperatures in cities being up to 10-15°C higher than in their rural surroundings during summer.
The urban heat island effect is expected to worsen in the future due to climate change, with temperatures increasing by more than the average of 2°C, and heat days being 4°C warmer in Europe. In many cities, the urban heat island effect is more pronounced in poorer urban areas characterized by dense and unregulated urbanization.
However, very locally, where trees are planted, the impact on the urban heat island effect can be noticeable, but on one street further, it will be warmer again. This underscores the need for comprehensive and integrated urban planning strategies to effectively combat the urban heat island effect.
Approximately 40% of Europe's total population lives in cities, and around 70% reside in urban areas. As urbanization continues, it's crucial that cities prioritize climate-friendly and heat-resilient urban development to ensure livable cities for future generations.
The City of Brussels, as part of its comprehensive heat-resilient urban development, is incorporating environmental-science-based strategies such as increasing urban greenery and creating green-blue networks to reduce the urban heat island effect. In the realm of health-and-wellness, city authorities are developing public information and adaptation policies to guide residents during heatwave events, showing locations of drinking water points, shaded green spaces, and cool zones like museums and fountains.
Furthermore, science plays a vital role in addressing climate-change-induced challenges like the urban heat island effect, as experts suggest redesigning cities to promote greenery, reduce concrete surfaces, decarbonize district cooling systems, and implement sustainable mobility and energy plans. This integrated approach, combining technical infrastructure, nature-based solutions, urban planning, and community engagement, is becoming essential for creating livable and climate-friendly cities across Europe.
