Increasing fire risks in cities worldwide under warming climate

Anthropogenic warming is known to have influenced vegetation fires. However, how, or to what extent, a warming climate will impact urban fire frequency remains unknown. Here we quantify the shift in the frequency of various urban fire incident types in response to a warming climate using a global fire incidents database collected from 2,847 cities. We find that the frequency of building fires increases quadratically, and the minimum occurs at thermal comfort temperature (that is, around 24.0 °C), while for every 1 °C increase in air temperature, the frequencies of vehicle and outdoor fires increase by (2.5 ± 0.8)% (mean ± standard error) and (4.7 ± 2.2)%, respectively. In the SSP5-8.5 scenario by 2100, we project that building fire frequencies could decrease by (4.6 ± 1.1)%, while vehicle and outdoor fires could increase by (11.6 ± 3.7)% and (22.2 ± 10.2)%, respectively. These findings can guide the development of climate-resilient strategies by providing quantitative advice on allocating and reallocating budgets for national fire services across cities. Although urban fire incidents cause enormous casualties due to dense population concentrations, the risks from these incidents under a warming climate remain unknown. This study analyzed a global database of urban fire incidents to quantify and predict changes in the frequency of various urban fire incident types in response to a warming climate, finding general increases in fire frequency.