Lightning is the primary cause of wildfires in Canada, accounting for nearly half of all fires and over 90% of the total area burned, according to a new study. The research warns that the effects of climate change are expected to increase the frequency of these blazes, as rising temperatures lead to more lightning strikes and drier vegetation.
A Growing Threat from Above
A study published in May 2025, which analyzed data from 2000 to 2020, found that fires ignited by lightning tend to be more destructive than those caused by human factors. This is because lightning-induced fires often occur in isolated, hard-to-reach regions and can ignite in clusters, overwhelming fire management agencies.
Scientists have also found a direct link between climate change and the increase in cloud-to-ground (CG) lightning. Warmer temperatures, changes in moisture, and altered atmospheric circulation patterns are contributing to more frequent lightning events. This trend is not unique to Canada; a separate study noted that CG lightning is responsible for over two-thirds of the total area burned in the western United States.
Beyond Wildfires: The Cascading Effects
The risks associated with this phenomenon extend beyond just fires. The same weather patterns that increase lightning can also lead to flash floods and slope failures, especially in recently burned areas where the ground’s ability to absorb water is compromised. This means that regions impacted by wildfires are at a higher risk of subsequent hydrologic disasters.
Researchers are using tools like the Canadian Forest Fire Weather Index (FWI) System to predict future fire risks. Their models forecast an increased coincidence between lightning-producing days and high fire risk scores by mid-century, underscoring the urgent need for new strategies to manage these natural disasters.