A comprehensive new study analyzing nearly four decades of global disaster data reveals that while hundreds of thousands of lives have been saved through improved preparedness and infrastructure, climate-related death risks are increasing in some regions due to rising exposure and intensifying hazards.
The research, led by Benjamin B. Cael, assistant professor in the Department of Geophysical Sciences at the University of Chicago, examined nearly 2,000 of the world’s deadliest climate hazard events recorded since 1988. Drawing on data from EM-DAT, the largest public database of disaster-related mortality, the study identifies long-term trends in how floods, storms and extreme temperatures affect populations across different continents.
Published in Geophysical Research Letters, the study takes a statistical approach that looks beyond individual catastrophic events to uncover broader shifts in vulnerability, exposure and preparedness over time.
“The deadliness of climate hazards reflects more than just the weather,” Cael said. “By looking across decades of data, we can see how changes in exposure, vulnerability and preparedness are shaping risk over time, alongside climate change.”
Asia shows measurable progress
One of the most significant findings comes from Asia, where floods and storms have become both less frequent and less deadly since the late 1980s.
The study attributes this progress primarily to reduced vulnerability resulting from sustained development efforts. Investments in stronger infrastructure, improved flood defenses, more reliable early warning systems and more effective emergency response mechanisms appear to have significantly reduced mortality rates.
Using conservative estimates, the analysis suggests that these improvements have saved approximately 350,000 lives over the past several decades.
Although floods and storms continue to pose serious threats across Asia, the findings demonstrate that long-term investment in disaster preparedness and risk reduction can produce measurable and life-saving results.
Africa faces rising exposure
In contrast, the study identifies a concerning trend in Africa, where deadly floods and storms have become more frequent.
Unlike Asia’s improvements driven by reduced vulnerability, Africa’s rising mortality risk appears largely linked to increased exposure. Rapid population growth in flood-prone areas has placed more people directly in harm’s way. As a result, when floods and storms strike, the number of fatalities can be significantly higher.
The analysis also contextualizes recent catastrophic events. Storm Daniel, the Mediterranean cyclone that caused devastating flooding in Libya in 2023, stands as Africa’s deadliest recorded storm. According to the study’s statistical modeling, a flood or storm of comparable deadliness in Africa would typically be expected to occur only once every few centuries.
This finding underscores how rare but extreme events can still drive enormous human losses, particularly in regions where vulnerability and exposure remain high.
Europe sees growing heat-related deaths
The study also highlights shifting patterns in Europe, where temperature-related hazards have changed character.
Deaths linked to extreme temperatures have increased, largely because heatwaves have become more frequent relative to cold extremes. As climate change alters temperature patterns, heat events are emerging as a more dominant and deadly hazard.
This shift illustrates that climate change not only affects how often hazards occur but also changes the types of hazards that pose the greatest risks to human health.
Taken together, the findings show that global climate hazard mortality does not follow a single upward or downward trajectory. Instead, outcomes depend on the interplay between climate change, demographic trends, infrastructure investment and institutional preparedness.
In parts of Asia, sustained efforts to reduce vulnerability have led to substantial reductions in disaster deaths. In parts of Africa, increasing exposure has amplified risks. In Europe, changing temperature extremes are reshaping mortality patterns.
The research emphasizes the importance of systematic, long-term monitoring of disaster mortality data. Understanding how risks evolve over time can help policymakers identify where interventions are working and where additional resources are urgently needed.
As climate change continues to intensify hazards worldwide, the study suggests that investments in preparedness, infrastructure and risk reduction remain among the most effective tools for saving lives.