1254. As Climate Change Progresses, More Will Be Exposed to Extreme Events

Extreme events are intensifying due to anthropogenic climate change. Extreme climate events that have harmful effects on society are the biggest concern regarding climate change. Human influence on climate change has also been observed in extreme events such as heat waves, river floods, droughts, crop failures, wildfires, and tropical cyclones. As warming continues, the intensity, frequency, and duration of these events are predicted to increase further. Under current policies, it is highly likely that global average temperatures will rise by 2.7°C (2.2–3.4°C) above pre-industrial levels by the end of this century.

Extreme climate events are predicted to occur most frequently during the lifetimes of the current young generation, and the number of such events experienced by people in their lifetimes may far exceed the levels that could be experienced under pre-industrial climate conditions. A paper published in Nature used climate models to predict the number of people who will experience cumulative lifetime exposure to unlikely levels of extreme events that exceed the 99.99th percentile of exposure expected under a pre-industrial climate.

The analysis showed that if global temperatures rise by 2.7°C above pre-industrial temperatures by 2100 under current mitigation policies, the proportion of birth cohorts (groups of people born during a certain period of time) facing unprecedented exposure to extreme events such as heat waves, crop failures, river floods, droughts, wildfires, and tropical cyclones in their lifetimes will be at least twice as high as that between 1960 and 2020. In the 1.5°C pathway, 52% of people born in 2020 are expected to experience unprecedented exposure to heat waves in their lifetimes, while in the 3.5°C pathway, this proportion increases to 92% for heat waves, 29% for crop failures, and 14% for river floods. In particular, populations with high socio-economic vulnerability are significantly more likely to be exposed to unprecedented heat waves in their lifetimes.

The authors called for a deep and sustained reduction in greenhouse gas emissions to reduce the burden of climate change on the current younger generation.

(Reference)
Grant, L., Vanderkelen, I., Gudmundsson, L. et al. Global emergence of unprecedented lifetime exposure to climate extremes. Nature 641, 374–379 (2025). https://doi.org/10.1038/s41586-025-08907-1

Contributor: IIYAMA Miyuki, Information Program