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UrbanClimate research reveals how Malta鈥檚 historic cities could help tackle rising urban heat
Historic cities may already hold part of the answer to rising urban heat, according to findings presented at the UrbanClimate Public Workshop held on Friday, 7 August 2026, at the University of Malta’s Valletta Campus. The event brought together researchers, heritage professionals, public authorities and stakeholders to discuss how Malta’s historic urban fabric responds to heat today and how it may perform under a changing climate.
At the centre of the workshop were results from UrbanClimate, a project using satellite observations, drone surveys, ground measurements, artificial intelligence and climate modelling to examine heat patterns at the scale of streets, roofs and individual buildings.
The project builds on earlier research into the thermal behaviour of traditional, modified traditional and modern roofs, while extending the investigation to the wider urban environment. This was led by Prof. JoAnn Cassar from the Department of Conservation and Built Heritage of the Faculty for the Built Environment and by Prof. Charles Galdies from the Institute of Earth Systems. Additional project researchers included Ing. Elizabeth Muscat Azzopardi, Francesca Soster and Benjamin Mifsud Scicluna.
One of the clearest findings came from the project’s study of Birgu (Vittoriosa) and Bormla (Cospicua). Data centred on a survey carried out on 22 June 2025 showed that Bormla had an average surface temperature around 2°C higher than Birgu, with larger and more intense hotspots. Birgu, by contrast, showed a greater number of smaller, more scattered hotspots, affecting a wider range of streets and buildings. Researchers stressed that the survey provides an indicative snapshot rather than proof of year-round conditions.
The longer-term picture raises an important warning. Under a high-emissions scenario, surface temperatures of 32°C and above are projected across almost all studied areas by 2081-2100. The modelling represents climate-adjusted present-day spatial patterns rather than independent forecasts for individual streets, but it indicates that future heat pressure could become considerably more extensive.
UrbanClimate also demonstrates why different technologies need to work together. Thermal satellite observations provide a repeatable, wider view of urban heat, while very-high-resolution drone mapping remains essential for identifying differences between individual streets, roofs and buildings. AI and machine-learning techniques are meanwhile being used to increase the usefulness of satellite thermal imagery for heritage-scale analysis.
Importantly, the findings suggest that historic fabric should not be viewed only as something vulnerable to climate change, but also as a potential climate-resilience asset. Traditional roofs in Birgu (known in Maltese as deffun roofs) were observed to be cooler on average than modified and hybrid roofs during the survey. Although the researchers caution that this does not demonstrate a universal cooling effect, the results support conserving, compatibly repairing and monitoring intact traditional deffun roofs rather than replacing them indiscriminately.
Streets from the two cities were ranked on the basis of their exposure to urban heat. They have been identified for heritage-sensitive, stepwise pilot measures. The recommended approach is to conserve, test carefully, measure results and expand successful interventions rather than introduce sweeping permanent changes.
The programme also included contributions from Vilnius University, the Superintendence of Cultural Heritage and Heritage Malta, followed by stakeholder discussion.
UrbanClimate is now turning its scientific findings into practical guidance for heritage authorities, professionals, Local Councils and homeowners. Its central message is compelling: protecting historic places and adapting cities to rising heat need not be competing goals.
The UrbanClimate project gratefully acknowledges the financial support of XjenzaMalta through its National Space Research Fund 2023, together with the support of the . The project also benefited from the expertise and collaboration of , which contributed AI-based super-resolution modelling; SISTEMA, which supported thermal data stitching and processing; , which carried out UAV flight operations; the , which supported satellite overpass tasking and coordination; and the Institute of Aerospace Technologies at the University of Malta, which assisted with UAV operations.
The UrbanClimate team further acknowledges the valuable cooperation of the , , the Local Councils of Birgu, Bormla and L-Isla, and the , whose engagement and local knowledge contributed to the successful implementation of the project. Together, the contribution of these funding bodies, scientific partners, technical collaborators and heritage stakeholders made possible the multidisciplinary research linking Earth Observation, climate science and the conservation of Malta’s historic urban environment.
