A team from the University of Graz led by Gottfried Kirchengast has introduced a new mathematical model that quantifies climate hazards from extreme events—like heat waves, floods, and droughts—by measuring how often they occur, how long they last, how intense they are, and how widespread they become.
The approach enables year-by-year and decade-by-decade tracking of climate hazard metrics wherever long-term data exist.
This makes it possible to attribute rising risks to emission-intensive actors such as states or companies.
Applying the method to European daily maximum temperatures from 1961–2024, the researchers define extreme as the top 1% relative to a 1961–1990 baseline.
This yields a striking picture of changing risk patterns across the continent.
What the new hazard model measures and why it matters
The novel framework quantifies four interconnected dimensions of climate hazards: frequency, duration, intensity, and spatial extent.
By combining these metrics, it creates a holistic measure of “extremity” that can be tracked over time and across regions.
This is a major step beyond single-parameter indicators, because extreme heat, for example, can become more dangerous not only by becoming hotter, but also by lasting longer and covering larger areas.
Key features include its local baselines, flexible temporal scope, and the ability to attribute changes to human activity wherever data permit.
The researchers emphasize that the approach supports accountability by linking shifts in hazard exposure to emission-intensive actors.
How the model works and what data it uses
Data inputs: long-running, high-quality climate records (daily temperature in the European study), carefully chosen baselines, and clearly defined regional thresholds.
The team applies a local definition of extreme based on historical context, ensuring that regional climate dynamics are respected.
Metrics and attribution: the model computes changes in the frequency, duration, intensity, and spatial extent of extremes and then aggregates them into a comprehensive hazard metric.
By comparing decade-spanning trends with a historical baseline, the method can attribute increases in hazard to human-driven emissions where natural variability does not explain the observed pattern.
- Frequency of extreme events increasing over time
- Duration of events lengthening, extending exposure windows
- Intensity of the extremes rising beyond historical norms
- Spatial extent of heat or other hazards spreading to new areas
European findings: a clear signal of rising heat extremity
Applied to daily maximum temperatures across Europe from 1961–2024, the study finds a pronounced rise in the total extremity of heat in Austria and much of Central and Southern Europe.
In the 2010–2024 window, the total extremity of heat is roughly ten times higher than in 1961–1990.
The researchers contend this increase far exceeds natural climate variability, presenting compelling evidence that human-made climate change is driving more frequent and intense heat extremes across the region.
Linking hazards to health and economic outcomes
In recent summers, extreme temperatures—peaking around 40°C in parts of Europe—have been associated with thousands of deaths.
Independent work from Imperial College London and the London School of Hygiene & Tropical Medicine attributes about 68% of an estimated 24,400 heat-related deaths to climate change, with temperatures raised by as much as 3.6°C in affected regions.
The same line of research notes substantial short-term economic costs linked to extreme summer weather, with at least €43 billion in 2025 losses and projections of €126 billion by 2029.
Economic damages and regional exposure in the European Union
A related study led by Dr. Sehrish Usman and ECB collaborators finds that a quarter of EU regions experienced heatwaves, droughts, or floods during summer 2025, producing immediate losses amounting to roughly 0.26% of the EU’s 2024 economic output.
Projecting these losses forward suggests that climate risk is not only a health or environmental issue but a material economic risk facing European economies in the near term.
Why location-specific attribution matters for policy and accountability
The strength of the new modelling approach lies in its ability to deliver precise, location-specific attributions of climate impacts.
By quantifying how much human activity has increased extreme-weather risks in a given place, the method provides a powerful tool for policy design, accountability, and corporate responsibility.
Governments, businesses, and insurers could use these metrics to align adaptation investments, price climate risks, and evaluate the responsibility of emitters affecting vulnerable communities.
Here is the source article for this story: Groundbreaking study reveals tenfold heat increase over Europe