Hot future for Freiburg: This is how the city becomes a heat hotspot!

Hot future for Freiburg: This is how the city becomes a heat hotspot!

Freiburg is facing a significant challenge: the city will be increasingly affected by heat stress due to climate change. A new study carried out by the University of Freiburg in collaboration with the Karlsruhe Institute of Technology (KIT) predicts an alarming development of hot days by the end of the 21st century. This research uses an AI model to create a precise simulation of the urban climate for the period 2070 to 2099. Loud uni-freiburg.de Under the pessimistic scenario, the city could face temperatures above 32°C for up to 307 hours per year. This represents a drastic increase compared to the reference period from 1990 to 2019, where there were an average of 135 hours of high heat stress.

The situation will be particularly dramatic in the case of very high heat stress (>38 °C), the number of hours of which could increase to 71 hours per year in the most pessimistic scenario - an increase of ten times compared to just 7 hours per year during the reference period. However, the heat load is not evenly distributed; it varies considerably within the city depending on building density, vegetation and air circulation. The study examined various urban areas, including industrial areas and residential areas with mature trees.

Challenges presented by urban conditions

Freiburg is one of the hottest cities in Germany, which is mainly due to its location in the Upper Rhine Graben. The ever-increasing number of hot days above 34 °C and tropical nights above 20 °C poses significant challenges. In addition, urban areas are more affected by heat stress than the surrounding areas due to their dense development and the high degree of sealing of the areas. This was also recognized in the climate adaptation concept that was created in the city planning office in 2018 in order to secure the quality of life in the long term. The concept focuses on the area of ​​action “heat” and highlights central questions about the urban climatic situation and effective adaptation measures, such as freiburg.de reported.

The core areas in this concept include the green and open space system as well as the city and building structure. Plans include, among other things, the planting of large-crowned trees, the greening of roofs and facades, and measures to provide shade for buildings and public spaces. In addition, the protection of airways coming from the Black Forest and the desealing of areas are emphasized. This is intended to ensure better networking of open spaces.

Climate adaptation as a priority

The concept includes several packages of measures that are specifically tailored to different urban structure types, such as row developments or commercial areas. The adaptation is carried out through a combination of different measures, such as the creation and protection of airways, the maintenance and creation of new public open spaces and the improvement of accessibility to green and forest areas. These measures will not only be taken into account in the urban development plans, but will also be included in the new development of the 2040 land use plan.

The relevance of the concept was underlined by awards: In 2023 it was recognized with second place at the German Urban Development Prize in the special prize “Shaping Climate Change” category and in 2019 it received the prize in the “Climate Active Municipalities” competition of the Federal Environment Ministry. This recognition shows the city of Freiburg's committed approach to meeting the challenges of climate change and ensuring quality of life in the future.

Overall, the interdisciplinary collaboration between the University of Freiburg and KIT as well as the city's commitment makes it clear that climate change is just around the corner and that it must be taken seriously.