How does climate change affect Innsbruck?

Climate change is happening. And it's happening at an accelerating pace - faster than the original projections calculated.

By 2020, average global warming was 1°C. In Austria, the average temperature has risen by around 2°C since 1880. These measurements show that the Alpine region and thus also the Tyrolean capital will have to reckon with about twice the warming than the global average.

The warming trend - on this scale and at this speed - is clearly noticeable for all residents of the city of Innsbruck. This was especially evident in the summer of 2022: The number of heat days and the intensity of heat periods increases noticeably and a seasonal shift of the occurrence of the 1st heat days is clearly visible.

in 2020 , a survey of Innsbruck's climate and an overview of urban climate modeling with a focus on heat stress was carried out in cooperation with the
Central Institute for Meteorology and Geodynamics (ZAMG) prepared.

Heat as a challenge

Climate change has many facets, but heat poses particular challenges to cities due to dense development, sealed surfaces, and often low air exchange that brings cooling.

Modeling shows an increase in the frequency of summer and heat days: with 25 heat days, Innsbruck has twice as many heat days as Salzburg (12) and 10-20% more than Klagenfurt (max. 21). The temperature differences between the densely populated inner-city area and the urban periphery can be as much as 6°C.

In addition to heat, drought, heavy rainfall events and extreme wind phenomena are also increasingly affecting cities.

City Climate Analysis Innsbruck 2022

The urban climate analysis was developed by the City Department Urban planning, urban development and integration and by the City Office Office of the Magistrate - Climate & Environment .. and prepared by Weatherpark GmbH in cooperation with the Institute for Climate and Energy Concepts (INKEK GmbH).

It is an area-wide, systematic as-is analysis of Innsbruck's urban climate, was prepared according to the VDI (Association of German Engineers) and supplemented by a summer measurement campaign.

Based on the urban climate analysis, for example, fresh air and cold air pathways are located in order to be able to protect them in a more targeted manner. The analysis also shows which areas of the city are particularly overheated and which local adaptation measures (greening, unsealing, etc.) are necessary.

Results of the urban climate analysis

The urban climate analysis includes - in addition to a comprehensive results report including recommendations - the following maps:

• Theme maps (building volume, cold air and ventilation) provide the basis for the climate analysis map and the planning advice map.
• The Climate analysis map contains a synopsis of the climate phenomena relevant in the urban area and their spatial distribution. In order to do justice to the extreme topography of Innsbruck, the climatope "Reizklima" was developed. This high mountain climate is characterized by short summers and long and cold winters. Its importance lies in the interaction with the valley areas via the cold air conduction paths during warm summer nights. The Sill gorge and the course of the Sill through the city also represent a special structure; they form a fresh air corridor that reaches far into the city. These are just a few of the special features of the climate analysis map now available.
• The Planning Advice Map evaluates the partly complex urban climatic functions. Thus, the climatic sensitivity of different areas can be determined and their value spatially assigned. The resulting recommendations and hints aim at improving climatic conditions, coordinating future urban developments and mitigating the effects of the predicted climate change as far as possible.
  The planning notes map was divided into six categories: two categories are compensation areas, which are areas worthy of protection due to cold air. Four categories concern partially or completely built-up settlement areas, which are designated with more or less thermal load. For all categories, there are concrete recommendations with a mix of proposed measures.
• Scenario maps: For a climate-conscious, sustainable urban development it is not only necessary to react to the actual situation, but also to consider the expected changes. For this purpose, scenario maps were created for Innsbruck, which show the effects of future urban development and the predicted climate change until 2100 in a striking way:
  • Urban development "continue as before" in relation to the current state climate and the climate forecast RCP 8.5
  • Urban development "strong focus on climate change adaptation" in relation to the actual state climate and the climate forecast RCP 8.5

Improving the quality of life and protecting vulnerable groups

In order to keep the quality of life high - despite the already noticeable and unavoidable impacts of climate change - climate change adaptation is necessary on a city-wide and strategic level.

The results of the urban climate analysis underline the importance of (cold) airways for night cooling. Even though the number of heat days is increasing, the city of Innsbruck does not (yet) record a significant increase in tropical nights. Nights when the minimum temperature does not drop below 20°C are considered to be particularly stressful for the human organism.

Vulnerable groups such as elderly and impaired persons or small children are particularly affected. It is important to protect these groups and to implement measures such as building structures at an early stage, but also to expand public relations work and early warning systems.

Outlook

The results of the urban climate analysis are to be integrated into all processes within the municipal administration and also in cooperation with the municipal participations, and the implementation of measures - based on the recommendations - is to be broadly applied in the respective fields of action. This primarily concerns the following fields of action:

• Planning processes: Implementation of the findings of the urban climate analysis in planning processes at different planning levels. Regular evaluations are to ensure that the city's internal processes are practicable and goal-oriented. Indicators, threshold and limit values for the establishment of a city-internal system for the application of the urban climate analysis are to be elaborated and corresponding proposals for binding framework conditions (in the sense of obligatory requirements and recommendations) are to be made.
• Risk management and early warning systems: The risk analysis of the climate change adaptation strategy is to be revised based on the new findings of the urban climate analysis and risk management is to be adapted accordingly. Based on vulnerability analyses, important socio-economic conclusions can be drawn and prioritizations can be made.
• Communication processes (internal and external): interdisciplinary cooperation within the municipal administration is an essential building block for a successful handling of the results of the urban climate analysis, but it is also important to raise awareness among stakeholders and the population. This requires not only technical information but also a broad-based communication strategy. Also beyond the city limits, a strengthening of the cooperation with the surrounding communities, the promotion of national (city cooperation) and international exchange with cities should be pushed.