Swiss Re SONAR 2025 Flags Extreme Heat as Top Emerging Risk with Half-Million Annual Deaths

Swiss Re SONAR 2025 Flags Extreme Heat as Top Emerging Risk with Half-Million Annual Deaths

(IN BRIEF) Swiss Re’s 2025 SONAR report identifies extreme heat as a leading emerging risk, attributing up to 500,000 deaths annually to heatwaves—more than floods, quakes, and hurricanes combined. The report traces rising severity and duration of heat events, notes USD 78.5 billion in wildfire losses (2015–2024), and warns of growing liability claims against companies for climate negligence. It also examines related threats like toxic fungi, agricultural losses, and worker injuries. Additionally, SONAR covers structural risks including declining institutional trust and a 60 percent surge in AI incidents, urging insurers to recalibrate coverage in an increasingly complex risk landscape.

(PRESS RELEASE) ZURICH, 13-Jun-2025 — /EuropaWire/ — Swiss Re today highlights extreme heat as one of the most critical emerging risks in its 2025 SONAR report, revealing that up to half a million people die annually from heat-related causes—surpassing fatalities from floods, earthquakes, and hurricanes combined. The study underscores the wide-reaching impacts of more frequent and severe heatwaves, not only on human health but also on industries ranging from energy to telecommunications.

“Once dubbed the ‘invisible peril,’ extreme heat is now unmistakably taking its toll on lives, economies, and infrastructure,” says Jérôme Haegeli, Swiss Re’s Group Chief Economist. “With heatwaves growing longer and hotter, it’s vital to illuminate the true costs to our healthcare systems, agricultural output, and critical services.”

Beyond the grim mortality figures, extreme temperatures fuel wildfires—driving USD 78.5 billion in insured losses between 2015 and 2024—and strain business operations, from data-center cooling failures to cable damage in telecom networks. Legal exposure is also rising, as corporations face lawsuits for inadequate climate mitigation; a notable 2021 case saw a US plaintiff seek USD 52 billion from fossil fuel companies.

The report also flags secondary hazards worsened by heat: the spread of toxic fungi, crop failures, and a surge in workers’ compensation claims. Meanwhile, Swiss Re’s SONAR delves into structural challenges such as eroding trust in institutions and the rapid uptick in AI-related incidents—up more than 60 percent between 2023 and 2024—spotlighting the need for insurers to define AI coverage and exclusions.

“Today’s risk environment is deeply interconnected,” observes Patrick Raaflaub, Swiss Re’s Group Chief Risk Officer. “From intensifying heatwaves and liability exposures to evolving AI threats, insurers must broaden their horizons and adapt to these macro trends reshaping global risk.”

About SONAR 2025

Swiss Re’s annual SONAR report identifies and assesses risks that could impact the global economy and the insurance industry in coming years. By providing early insights into potential new and evolving risks, the report aims to help businesses and insurers to better understand potential exposures and integrate this knowledge into decision-making processes.

SONAR topics 2025:

Structural risks

Declining consumer trust in institutions, including insurers

Social inflation risks could expand liability claims

Excess mortality variance: uncertainty for L&H claims and reserves

Ageing populations: mortality protection products at risk

Digital technology: mostly a liability insurance story

Emerging risks

Extreme heat: the insurance fallout

New frontiers in fungi-related loss potential

Deep fakes and disinformation: enabling insurance fraud

New technologies in healthcare delivery

The expanding horizons of drone technology

Plastics: a new wave of litigation?

Ultra-processed foods – health and liability risks

Emerging workforce gaps and skillset shortages

How to order SONAR:

Swiss Re’s SONAR can be downloaded from Swiss Re’s website.

[1] Climate Change Indicators: Heat Waves, US Environmental Protection Agency (EPA), June 2024.

[2] Zhao et al., Global, regional, and national burden of mortality associated with non-optimal ambient temperatures from 2000 to 2019: a three-stage modelling study. The Lancet Planetary Health, vol 5, 2021.

[3] AI Incidents Database, Waking UP Foundation, accessed 30 March 2024.

Disclaimer
Although all the information discussed herein was taken from reliable sources, Swiss Re does not accept any responsibility for the accuracy or comprehensiveness of the information given or forward-looking statements made. The information provided and forward-looking
statements made are for informational purposes only and in no way constitute or should be taken to reflect Swiss Reʼs position, in particular in relation to any ongoing or future dispute.
In no event shall Swiss Re be liable for any financial or consequential loss or damage arising in connection with the use of this information and readers are cautioned not to place undue reliance on forward-looking statements. Swiss Re undertakes no obligation to publicly revise or update any forward-looking statements, whether as a result of new information, future events or otherwise.

About Swiss Re
The Swiss Re Group is one of the world’s leading providers of reinsurance, insurance and other forms of insurance-based risk transfer, working to make the world more resilient. It anticipates and manages risk – from natural catastrophes to climate change, from ageing populations to cyber crime. The aim of the Swiss Re Group is to enable society to thrive and progress, creating new opportunities and solutions for its clients. Headquartered in Zurich, Switzerland, where it was founded in 1863, the Swiss Re Group operates through a network of around 70 offices globally

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SOURCE: Swiss Re