If fossil fuel usage is not reduced and indiscriminate urban development continues until 2100, it is expected that vehicle and outdoor fires will increase in cities around the world.
A research team from China University of Science and Technology, Australia’s Royal Melbourne Institute of Technology, and the National University of Singapore noted on the 3rd (local time) in the international journal Nature Cities that if the current trend of warming continues until 2100, vehicle fires will increase by 11.6% and outdoor fires by 22.2%. This study analyzed the most comprehensive dataset of urban fire incidents collected to date.
Climatologists report that the Earth has already crossed the threshold of the worst climate scenarios. Last year, global temperatures surpassed the 1.5-degree limit set by the Paris Agreement on climate change signed in 2015. Urban areas, which are densely populated, are also bearing the brunt of climate change.
The wildfires that struck Los Angeles earlier this year are assessed to have caused extensive damage due to severe drought effects stemming from climate change. Experts predict that as global warming worsens, fires will become more frequent in cities, leading to greater loss of life and property.
The research team built a database of fire incidents occurring in 2,847 cities across 20 countries, including South Korea, China, and Japan, from 2011 to 2020. These cities are home to 20.6% of the global population. The researchers classified the frequency changes of fire incidents caused by warming impacts on urban buildings, vehicles, and outdoor areas. They then assessed how much global warming is expected to influence future urban fires based on climate scenarios from the Intergovernmental Panel on Climate Change (IPCC), applying five scenarios from efficient greenhouse gas reduction (SSP1-1.9) to speculative high-emission scenarios (SSP5-8.5).
The research team confirmed that if global warming continues as it is now, the frequency of urban fires in the 20 countries will increase by an average of 3.3% for every 1-degree rise in temperature. It is reported that the frequency of vehicle fires will increase by 2.5% and outdoor fires by 4.7%.
If the scenario with the highest greenhouse gas emissions is applied until 2100, the average fire frequency will rise by 15.7%. The average frequency of vehicle and outdoor fires is shown to increase by 11.6% and 22.2%, respectively. Notably, the frequency of vehicle fires is predicted to rise in all 20 countries. By country, New Zealand is expected to have the highest increase in fire frequency, followed by the United Kingdom, Finland, Estonia, and Sweden. In contrast, South Korea, Japan, China, Cyprus, and Greece are expected to see a decrease in overall fire frequency.
The research team said, "The forecast of extreme weather suggests that measures to improve vehicle durability are needed." On the other hand, the frequency of building fires in the 20 countries is expected to decrease by an average of 4.6% by 2100, thus offsetting other types of fires.
The research team explained that varying weather conditions in different cities strongly influence fire occurrence rates. Cities with cold and humid climates have characteristics that make them more vulnerable to global warming. In such cities, a 1-degree increase in temperature leads to a 0.32% decrease in fire occurrence frequency, while a 1% increase in relative humidity results in a 0.1% increase in fire occurrence frequency. This indicates their sensitivity to temperature changes. For every 1 km increase in altitude where a city is located, the frequency of fire occurrences decreases by 1.36%.
The research team noted that they did not find a significant relationship between urban population density and fire frequency in this paper. However, they explained that high-density cities exhibited relatively fewer vehicle and outdoor fires, indicating that global warming has less impact on outdoor and vehicle fires in such areas.
The research team explained that in the case of outdoor ignition, repeated high temperatures could lead to fires originating from building exteriors or debris and waste. For vehicles, prolonged high-temperature environments can lead to more component failures, increasing the frequency of vehicle fires. The researchers analyzed that "the high usage rates of public transport in high-density cities might result in lower personal vehicle usage." They also indicated that for outdoor fires, the underlying reasons are not well understood and proposed a hypothesis that fire incidents may decrease as waste disposal facilities move to the outskirts of cities.
The research team also discovered that urban fires caused by global warming will likely lead to additional casualties. They analyzed that by 2100, at least 335,000 people could die and 1.15 million could be injured annually due to urban fires. The research team noted that "this estimate does not reflect the complex effects of climate change and is a conservatively made prediction" and added that if a mandatory goal of keeping global temperatures below 1.5 degrees is maintained, the number of fire casualties could be reduced by half.
The research team stated that this study does not include data from Africa and South America. They also explained that it does not sufficiently reflect the transition to electric vehicles since 2020. The team noted, "This research could provide a foundation for developing new strategies to combat fires, such as improving fire fuel management," and added that "these results are data-driven and could be useful for future urban planning and emergency response strategies."
References
Nature Cities (2025), DOI : https://doi.org/10.1038/s44284-025-00204-2