Exploring how heat stress evolves over time in districts and municipalities in Austria
With global temperatures on the rise, the health impacts of heatwaves are becoming an increasingly pressing concern, particularly for vulnerable populations like the elderly.
Researchers at the Complexity Science Hub have created an interactive map that tracks the evolving heat vulnerability across Austrian regions, offering a valuable data-driven tool to understand and mitigate these risks.
This interactive map allows users to explore how vulnerable different regions in Austria are to heat stress. It considers both the number of heat days and the proportion of the population over 65 years old, using data from 2018 to 2023.
- Very high vulnerability (dark red): Districts with more than 27.6 heat days per year and where over 22.8% of the population is older than 65.
- Very low vulnerability (blue): Districts with fewer than 14.9 heat days per year and less than 18% of the population over 65.
These classifications are based on a report analyzing the effects of additional heat days on mortality.
Users can also see how many tropical nights their municipality experiences, the average distance to the nearest hospital, and the amount of tree cover in residential areas. Additionally, the map offers projections for various future scenarios, helping residents, policymakers, and healthcare providers understand the heat risks in their areas and take necessary actions.
The map aims to help municipalities and districts take early preventive measures, such as greening initiatives, to protect vulnerable populations, especially the elderly.
INSIGHTS: AUSTRIA'S VULNERABILITY TO HEAT
According to the research findings, each additional day with temperatures exceeding 30°C during the summer months between 2015 and 2022 led to a 2.4% increase in mortality rates per 1,000 inhabitants across Austrian districts.
“The impact was more pronounced in areas where over 25% of the population was aged 65 and older, doubling mortality rates during heatwaves,” explains Hannah Schuster from CSH and the Vienna University of Economics and Business.
Furthermore, during heatwaves, defined as a week with three or more heat days, the rise in death rates was nearly three times higher compared to single heat days.
“In 2023, only 15% of districts had a quarter of their population aged over 65. By 2050, this figure is expected to rise to 80%, indicating a significant increase in heat-related health issues,” says Johannes Wachs from CSH. This demographic shift underscores the urgent need for preemptive measures to protect public health from escalating heat risks in the coming decades.
AUSTRIA'S GEOGRAPHIC DIFFERENCES
Heat vulnerability across Austria varies significantly due to climatic factors and demographics.
From 2018 to 2023, the number of districts facing medium to very high heat risk expanded. Eastern Austria, including Hollabrunn, Eisenstadt Umgebung, and Rust, recorded the highest heat stress levels in 2023, while Graz, Rohrbach, Tamsweg, Reutte, Imst, Dornbirn, and Feldkirch reported the lowest heat risk that year.
Vienna has a low heat risk index overall, which is due to the low average age of the population. The districts Innere Stadt and Hietzing , however, stand out as very high-risk areas due to their older demographics.
Looking ahead, without stringent emission regulations, most Austrian districts could face very high heat risk by 2050. However, adherence to strict climate policies (RCP 2.6) could moderate risks to a medium to high range. Despite occasional cooler years like 2020, the overarching trend towards warming temperatures underscores the imperative for proactive measures against heat-related challenges nationwide.
“For example, the year 2041 in the strict regulation scenario shows significantly higher heat stress compared to the moderate regulation scenario. However, it should be noted that overall, the moderate regulation scenario is associated with higher heat stress,” Schuster says.
POWERFUL GREEN
Addressing these challenges, researchers emphasize the positive impact of urban green spaces in mitigating heat-related health risks. “While local governments may not directly control global warming, expanding green spaces within cities offers effective, incremental solutions. Such investments are effective because cities can be greened piece by piece without high initial costs,” notes Schuster.
HEAT AND HEALTH: A GLOBAL CONCERN
High temperatures not only affect our mood and overall well-being but can also pose serious health risks, even leading to fatal outcomes worldwide.
This has been starkly demonstrated by recent events: the hundreds of deaths during the Hajj pilgrimage in southern Arabia, temperatures exceeding 40°C in the Balkans, 86 million people in the USA under a heat warning at the end of June, and the hottest night-time temperature ever recorded in New Delhi. Older adults are particularly susceptible to heat waves, with stark increases in mortality rates observed during periods of extreme heat.
