The extreme heat, high winds, and severe dry conditions that produce towering, fast-moving flames that advance by the acre are not just becoming more common; new research shows that these factors are increasingly arising in multiple regions at the same time, creating the conditions for simultaneous wildfires around the world.
In a study published in the journal Science Advances, researchers reported that the ideal conditions for major wildfires are now aligning across different parts of the world at more than double the rate they did nearly 50 years ago. Climate change is a major driver, accounting for about half of this increase. It’s the latest example of how humans are reshaping the nature of wildfires.
These changes have led to periods of inescapable smoke from blazes and more stress on firefighters, expanding the public health, economic, and social costs of infernos. As the climate continues to warm, these trends are likely to continue to worsen. Wildfire smoke is already linked to tens of thousands of premature deaths in the U.S., and recent years have shown how this smoke can cross continents and oceans, polluting the air for people far away from the flames. East Coasters might remember how Canadian wildfires a few years ago bathed cities like New York and Philadelphia in an amber haze, triggering air quality warnings. One study found that the smoke from those fires contributed to 82,000 deaths.
Meanwhile, the efforts to contain these devastating blazes are devouring money, time, engines, tankers, and firefighters, often beyond what local fire departments can muster on their own.
But with more wildfires burning in different parts of the world at the same time, countries will have their own blazes to deal with and less outside help will be available.
The result is that we may see more years with multiple major blazes at the same time, and you might find it harder to find clear air to breathe for growing swaths of the year.
(Yahoo News)
Cong Yin, the lead author of the study and a scientist at the University of California Merced, explained that research has been piling up showing that the weather conditions that favor major wildfires are becoming more common in different regions. Yin wanted to take a step back to see if there was a pattern that would emerge when he looked at the world as a whole.
Yin and his colleagues analyzed global climate and fire data between 1979 and 2024 and traced the fire weather index, a measure of fire dangers based on meteorological traits like temperature, wind, and moisture. The higher the index reaches, the greater the chances of a dangerous wildfire. The team drew on fire activity records from the Global Fire Emissions Database, which uses satellite data and ground-based measurements to track burned areas around the world. The team then counted the number of days where the fire weather index was in the 90th percentile in more than one region.
The results showed that over the study period, days with extreme fire weather conditions were increasing in places inside regions like North America, but also seeing severe fire weather line up across far-flung areas like North America and Europe. That makes it harder to coordinate firefighting efforts across borders.
We’ve seen in recent years that countries with major fires have received needed help from neighbors, and from farther away. Teams from Canada and Mexico joined the fight against the Los Angeles wildfires last year, even bringing equipment like tanker aircraft. During the wildfires in Spain last summer, the Netherlands, France, and Italy also sent firefighting aircraft. In past fire seasons, South Africa has sent firefighters to Canada. The U.S., Australia, and New Zealand have a standing firefighting cooperation agreement to share personnel and equipment between the countries.
However, worldwide, the number of days where severe fire weather has occurred in multiple places at the same time has more than doubled over the majority of fire-prone landscapes. With more fire weather occurring at the same time, countries may not be able to lend out tools and personnel as much because they’ll need everyone on deck at home.
When Yin and his team looked closer at regions like North America, climate variability drivers like the El Niño–Southern Oscillation, the periodic warming and cooling of the Pacific Ocean, tended to create fire weather conditions across the continent. The planet’s boreal regions — forested areas in northern latitudes — showed the highest levels of synchronized fire weather. They tend to experience extreme heat, little rain, and high winds at the same time more often. At the same time, the research identified areas where fire conditions are becoming less aligned, like Southeast Asia. The researchers think this is likely due to increasing humidity in tropical regions as temperatures rise. That can make it harder to achieve the ideal conditions for a major fire. (Yahoo News)