In the locality of Níjar (Almería, Spain), an outdoor trial demonstrated the potential of a new material to reduce extreme urban heat.
Under extreme solar radiation conditions —more than 1000 W/m² for several hours— its performance was compared to conventional cement. The result was clear: while the cement exceeded 56 °C, the new material remained around 40 °C, that is, 16 degrees less on the same surface.
This finding not only represents a significant thermal difference but also opens the door to practical solutions to mitigate the urban heat island effect, a phenomenon increasingly affecting densely populated cities.
How it works
The study, published in Cleaner Materials in 2026 and led by researcher G. Goracci, explains that the material:
- Reflects more solar radiation and absorbs less heat.
- Releases heat into the atmosphere without consuming energy, preventing thermal accumulation.
- Is manufactured from industrial waste, dispenses with traditional clinker, and captures CO₂ during its formation, reducing its environmental impact.
In simple terms: less heat enters and the heat that does enter dissipates better, keeping the surface cooler even in extreme conditions.
Impact on cities
Urban surfaces —streets, sidewalks, roofs— act as heat accumulators during the day and release it at night, making it difficult for temperatures to drop. Reducing this effect can:
- Decrease the thermal sensation in summer.
- Reduce energy consumption related to air conditioning.
- Break the “dangerous loop” where more heat means more cooling and higher emissions.
The material could be applied in pavements, roofs, and facades, especially in warm regions like southern Spain, where solar radiation is intense.
Viability and challenges
The trials confirm that the material has sufficient resistance for basic construction uses, but researchers warn that it is still necessary to:
- Validate its long-term durability.
- Analyze its industrial viability and costs for large-scale production.
Almería is consolidated as a key environment to test these solutions under extreme climate conditions, offering valuable data for future applications in other Mediterranean and warm climate cities.
The experiment demonstrates that acting on construction materials can be a powerful tool against urban heat. Although it does not cool the air directly, it prevents surfaces from accumulating and releasing excessive heat, becoming an active part of climate change adaptation strategies.
