Green spaces are vital for countering the urban heat island effect and reducing heat stress on living organisms. But what does this actually mean? The cooling effect of urban green areas is not solely due to trees providing shade. It involves a more intricate process where green surfaces decrease the amount of solar energy that is converted into heat. Solar energy reaches the Earth as shortwave radiation.
Instead of turning into heat, some of this energy is used for plant photosynthesis and water evaporation, resulting in lower temperatures in the surroundings. So, the cooling effect relies not only on trees but also on lower vegetation and water surfaces. Modern architectural and urban planning approaches prioritise greening walls and rooftops of buildings (1, 2).
To combat the urban heat island effect, it’s essential to incorporate larger green spaces, including water features, in urban development plans. These approaches have proven to be highly effective in reducing heat stress on organisms and mitigating the heat island effect (3).
Park Zvezda serves as one example of such an area—the Municipality of Ljubljana provides 542 m² of public (larger) green spaces per resident, with access available within a maximum distance of 300 meters from densely populated areas (4). However, with summers in Ljubljana getting hotter, the continuous creation of new green spaces is crucial for the well-being of residents. In a 2020 survey, pedestrians and cyclists in Ljubljana highlighted the areas in the city that are most in need of greening.
The Ljubljanski ledenik (Ljubljana Glacier) project is an initiative dedicated to raising awareness about the significance, impact, and protection against heat waves. Discover more valuable content on posters strategically placed throughout the city centre and by visiting the following link. The project is co-funded by the Municipality of Ljubljana.
(1) Kadaverugu, R., Lama, S., Purohit, V., Mopati, S., Matli, C., Biniwale, B., 2022. Potential of Green Roofs in Heat Stress Mitigation—A Case of Nagpur City. Innovative Trends in Hydrological and Environmental Systems. Lecture Notes in Civil Engineering, 234, str. 367–383. DOI:10.1007/978-981-19-0304-5_27.
(2) Feitosa, R. C., Wilkinson, S. J., 2018. Attenuating heat stress through green roof and green wall retrofit. Building and Environment, 140, str. 11–22. DOI: 10.1016/j.buildenv.2018.05.034
(3) Aram, F., Higueras García, E., Solgi, E., Mansournia, S., 2015. Impact of climate change on urban heat island effect and extreme temperatures: a case-study. Quarterly Journal of the Royal Meteorological Society, 142, 694, str. 172–186. DOI: https://doi.org/10.1016/j.heliyon.2019.e01339