26 June 2026

 

Europe's latest heatwave is exposing a reality that climate scientists have warned about for years: much of the continent's urban infrastructure was designed for a cooler climate.

Across western and southern Europe, authorities have issued heat alerts, hospitals are preparing for increased admissions and transport networks are operating under growing pressure. Immediate responses remain familiar—public warnings, cooling centres, fans and air conditioning—but a more fundamental shift is taking place beneath city streets, inside buildings and across digital planning systems.

Cooling is no longer being viewed simply as a building service. It is increasingly becoming part of the infrastructure that allows cities to function safely during prolonged periods of extreme heat.

That transition reflects a broader climate trend. The Copernicus Climate Change Service has repeatedly identified Europe as the fastest-warming continent, with temperatures rising roughly twice as fast as the global average since the 1980s. At the same time, the European Environment Agency has warned that rising temperatures, ageing populations and continued urbanisation are driving demand for cooling in the buildings where Europeans spend most of their lives.

Like electricity, water and transport before it, cooling is gradually becoming a system that cities must plan, manage and invest in.

 

Cooling becomes a municipal utility

 

Perhaps nowhere illustrates that transformation more clearly than Paris.

The French capital already operates one of Europe's largest district cooling networks through Fraîcheur de Paris, a company owned by ENGIE and RATP under a 20-year concession that began in 2022. Rather than relying entirely on individual air conditioning units, chilled water is produced centrally and distributed through underground pipelines to offices, museums, hotels and public buildings across the city.

The network uses production plants, thermal storage facilities and the River Seine for free cooling whenever environmental conditions allow. Heat exchangers transfer cooling energy without mixing river water with the closed distribution network.

The project is now being expanded across every Paris arrondissement by 2042. ENGIE plans to add 158 kilometres of additional pipework, 20 production plants and 10 storage facilities, extending the network to more than 3,000 customers, including hospitals, childcare centres, retirement homes and other public facilities.

According to the company, the expansion will avoid around 300,000 tonnes of carbon dioxide emissions during the concession period while saving approximately 130,000 cubic metres of water annually. The network has operated on 100 percent renewable electricity since 2013.

District cooling will not replace conventional air conditioning everywhere. Dense city centres with large commercial buildings make the economics attractive, while historic neighbourhoods, fragmented property ownership and construction disruption remain significant constraints.

Nevertheless, Paris demonstrates an important shift in thinking. Cooling is no longer treated solely as an appliance inside individual buildings but as shared municipal infrastructure that can be planned and operated at city scale.

 

Before cities cool themselves, they need to understand heat

 

Infrastructure begins with information.

Before engineers can decide where to plant trees, install reflective roofs or expand cooling networks, they first need to understand how heat moves through the urban environment.

Artificial intelligence is becoming an increasingly important planning tool.

Google Research's Heat Resilience platform combines satellite imagery, aerial photography and machine learning to help city planners model how interventions such as tree planting or highly reflective roofs could reduce surface temperatures. Rather than analysing cities as uniform environments, the platform estimates heat exposure at neighbourhood level before physical investments are made.

Although the tool was initially piloted in American cities, its significance for Europe lies less in its geography than in its methodology. It allows planners to compare competing interventions digitally before committing public funds to construction.

Academic researchers are developing even more detailed models.

DeepShade, created by researchers including Arizona State University's Hua Wei, uses generative artificial intelligence to simulate how shadows move through cities over the course of a day. By combining satellite imagery with variables such as building geometry, solar angle and time of day, the system predicts where shade will naturally occur and where additional interventions may be needed.

That may sound like a minor urban design exercise. In reality, shade can determine whether streets, school playgrounds or public transport stops remain usable during periods of extreme heat.

The same analytical approach is increasingly being applied to urban heat islands. By combining satellite observations, local sensor networks and machine learning, cities can identify districts where dark surfaces, limited vegetation and restricted airflow trap significantly more heat than surrounding neighbourhoods.

Such insights also expose an important social dimension. Heat rarely affects cities equally. Wealthier neighbourhoods often benefit from more trees, wider streets and better-insulated housing, while lower-income communities frequently experience higher temperatures and fewer opportunities to escape them.

In that sense, AI is becoming part of the infrastructure itself—not because algorithms cool cities directly, but because they help determine where investments in cooling infrastructure will have the greatest impact.

 

Buildings become part of the cooling system

 

Cooling infrastructure is not limited to pipes beneath the ground or software in city control rooms. Increasingly, buildings themselves are being redesigned to absorb less heat before mechanical cooling is required.

That shift is driving interest in radiative cooling materials, reflective coatings and other passive technologies that reduce temperatures without consuming large amounts of electricity.

Radiative cooling exploits a well-understood physical principle. Certain materials can reflect incoming solar radiation while simultaneously emitting heat through the atmospheric window, a range of infrared wavelengths that escapes into space. What has changed in recent years is the ability of materials scientists to commercialise that principle for buildings, refrigeration, transport and industrial equipment.

US company SkyCool Systems has developed radiative cooling panels that improve the efficiency of existing refrigeration and air conditioning systems by dissipating waste heat without additional compressors or refrigerants.

Japan's SPACECOOL has taken a different approach with passive daytime radiative cooling films and membranes designed for buildings, logistics, outdoor equipment and transport. The company says its materials can reduce surface temperatures below ambient air temperature without using electricity.

Israeli company SolCold is developing sunlight-activated cooling coatings that combine highly reflective surfaces with radiative cooling, while France's Cool Roof France focuses on reflective roof coatings that limit heat absorption in commercial and industrial buildings.

These technologies are not direct competitors. Some actively exploit radiative cooling, while others simply reflect more sunlight. Their effectiveness depends on climate, humidity, building design and installation quality.

Yet they all point in the same direction: reducing heat gain before conventional cooling systems need to switch on.

That matters because Europe cannot simply install millions of additional air conditioners without consequences.

 

Why Europe needs a different cooling strategy

 

Air conditioning will remain essential in hospitals, care homes, schools and other buildings where protecting vulnerable people is a public health priority.

But relying exclusively on individual cooling units creates new problems.

Conventional air conditioning removes heat from inside buildings by releasing it outdoors. In dense city centres, that waste heat can raise street-level temperatures, making the urban heat island effect even worse. At the same time, simultaneous demand for cooling places additional strain on electricity grids during periods of peak consumption.

Europe also faces constraints that differ from many newer cities elsewhere in the world.

Historic city centres, listed buildings, narrow streets and ageing housing stock often leave little room for large-scale retrofits or external cooling equipment. Replacing entire districts is neither economically nor politically realistic.

That is why Europe's emerging approach increasingly combines multiple layers of cooling infrastructure rather than depending on a single technology.

District cooling reduces demand at neighbourhood scale. AI helps cities identify where interventions will have the greatest impact. Passive building materials reduce heat before electricity is consumed. Nature-based solutions lower temperatures across public spaces. Together, they create a system that is more resilient than any one technology alone.

 

Existing infrastructure is learning to cool itself

 

Europe is also finding new ways to adapt infrastructure that already exists.

Metro systems provide a clear example.

Underground rail networks generate heat from trains, braking systems, lighting, electrical equipment and thousands of passengers. During prolonged heatwaves, temperatures inside tunnels and stations can become increasingly difficult to manage.

Rather than replacing entire ventilation systems, operators are turning to artificial intelligence to optimise the equipment they already have.

Barcelona's metro network has adopted Sener's Respira platform, which continuously monitors temperature, air quality and energy consumption before adjusting ventilation accordingly. According to InnoTrans, the system manages more than 130 stations, over 170 kilometres of track and 324 ventilation fans. During summer operation it reduced station temperatures by more than 1.3°C while saving around 7.2 GWh of electricity annually, equivalent to approximately €1.7 million.

Madrid has followed a similar path. Working with Accenture, Metro de Madrid introduced a self-learning ventilation system that combines data on station temperatures, passenger numbers, train frequency, electricity prices and weather forecasts to determine how ventilation should operate throughout the network. Accenture reported that the system reduced ventilation energy costs by around 25 percent while cutting annual carbon dioxide emissions by approximately 1,800 tonnes.

Neither project eliminates heat underground. Instead, both demonstrate how software, sensors and predictive control can extend the capabilities of infrastructure that was designed decades before climate change became today's engineering challenge.

 

The next generation of urban infrastructure

 

For years, climate technology was largely associated with renewable energy, electric vehicles, batteries, hydrogen and carbon removal. Those industries remain central to reducing greenhouse gas emissions.

Europe's recent heatwaves highlight another rapidly emerging field: climate adaptation technologies that enable cities to continue functioning safely in a warmer world.

The examples already exist. Paris is expanding district cooling as a municipal utility. Artificial intelligence is helping planners map heat exposure before construction begins. Advanced materials are reducing heat absorbed by buildings. Metro operators are using predictive software to improve passenger comfort while lowering energy consumption.

Taken individually, these technologies solve different problems. Together, they represent something much larger: the emergence of cooling as a new layer of urban infrastructure.

Technology, however, is not the entire answer.

Urban planners have long understood the value of trees, parks, green roofs, water and shaded public spaces in reducing temperatures and improving resilience during extreme heat. Increasingly, deeptech is strengthening rather than replacing those natural solutions. AI can identify where additional tree cover will provide the greatest benefit. Digital twins can predict how redesigned streets or public squares will alter local temperatures before construction begins. District cooling and advanced materials can reduce heat where dense urban environments leave little room for additional greenery.

Europe's cities were built for a different climate. As temperatures continue to rise, keeping them liveable will require more than bigger air conditioners or smarter algorithms alone. The cities proving most resilient are recognising that cooling is becoming essential infrastructure—planned, networked and managed like any other public utility—and that the strongest solutions combine engineering with nature rather than choosing between them.