The climate crisis is expected to increase the frequency of lightning-sparked wildfires for decades, posing greater risks to public safety and health, according to new research. Lightning-caused fires tend to ignite in remote areas and grow larger than human-caused blazes, making them more dangerous and contributing to a surge in air quality issues.
Over the past 40 years, thunderstorms and conditions favouring lightning have become more common across much of the western United States, including Washington, Oregon, California and the Rocky Mountains. This trend is not limited to the US; this year's fire season in Europe has been the worst on record, partly due to lightning-caused fires in Spain, while in Canada, most of the huge fires burning over 200% of the normal forest area were caused by lightning.
A new study, published last week, is the first to use machine learning to examine how lightning and wildfires will change as the climate crisis deepens. The lead author, Dmitri Kalashnikov of the University of California-Merced, said: 'The overall signal is that we will have more risk of lightning-caused fires.' The team found that future increases in lightning-caused fires are expected across 98% of the western US, due to more lightning, more fire weather, or both.
The findings come as wildfires in the US intensify, with thousands of lightning strikes sparking at least 20 new fires in California this week. The study warns that a surge in lightning-caused fires could lead to more than 20,000 smoke-related deaths per year in the US by mid-century, up from about 1,000 annually over a recent 15-year period.
Additionally, increased lightning could raise the risk of flash flooding and mudslides in recently burned areas, and more smoke may coat glaciers in Canada, Greenland and Europe with dark particles, accelerating melting. Lightning-caused wildfires also strain emergency resources, as they often occur in remote areas and can 'stretch resources really, really thin' during peak fire season, according to University of California Cooperative Extension wildfire specialist Max Moritz.
