The records of the deadliest climate disasters that have occurred may be insufficient to predict the magnitude of extreme events that may still manifest. This is the conclusion of researchers from King's College London, as reported by the portal Phys.org, who point to a deficiency in the current tools used for climate risk assessment.
According to the scientists, although planning models can simulate occurrences more severe than those known, they find it difficult to conceive entirely unprecedented situations. This limitation could result in governments and other entities being unprepared for scenarios that generate significantly greater impacts on the population, infrastructure, and public health.
The study, published in the journal Nature Sustainability, examined the deaths caused by all tropical cyclones and extreme heat episodes documented globally between 2000 and 2025. The findings indicated that most victims were concentrated in a small number of major catastrophes.
A notable example is Cyclone Nargis, which hit Myanmar in 2008, resulting in nearly 140,000 deaths. This event was responsible for more than double the deaths recorded in the other 675 lethal tropical cyclones accounted for in the analyzed period.
Heatwaves show a similar concentration of fatalities. The deadliest case studied occurred in Europe in 2003, when approximately 70,000 people lost their lives. Almost half of these deaths happened only in the first two weeks of August, demonstrating the great impact that a brief period of extreme heat can cause.
The analysis led researchers to speculate that extremely rare future events could lead to death tolls in the millions. However, they emphasize that the mere possibility of such a scenario does not imply its probability.
Challenges in climate projection
For the researchers, one of the main obstacles lies in using the past as the primary reference to project the future. Contemporary climate already differs from that observed during much of the period in which historical records were compiled, while the most extreme events considered represent only what has been recorded so far.
Current methods are capable of operating with known situations, but at a high intensity; for example, it is possible to consider a hurricane with wind speeds higher than those already recorded. The problem arises when multiple extremes occur simultaneously, creating conditions without historical parallel.
A hypothetical scenario mentioned by the authors involves a destructive heatwave following a strong hurricane. In this situation, millions of individuals could need to evacuate their homes while facing conditions that reduce the availability of cooling systems and other protection against heat.
To mitigate this knowledge gap, the researchers propose three priorities. The first is to conduct preliminary assessments involving specialists from various fields, including directly affected communities, insurers, climate modelers, risk researchers, and climate fiction writers.
The second priority is to gain a clearer understanding of the limits from which the impacts of extreme events can abruptly grow. The third consists of outlining the physical limits of the climate under conditions much hotter or colder than currently observed.