Climate change probably did not make the deadly wildfires that swept across part of Chile in early February any more likely, according to a group of climate scientists and meteorologists who specialize in the rapid analysis of weather-related disasters.
Central Chile has been in the grip of a prolonged drought for more than a decade. On top of these dry conditions, the region experienced an intense heat wave at the beginning of February that raised the risk of wildfires.
According to the new analysis by the group, World Weather Attribution, the probability of these conditions, specifically for the coastal region of Chile where the fires occurred, is now about 3 percent in any given year. That risk is not significantly higher than it was before human-caused climate change.
The fires hit the area around the coastal city of Viña del Mar. More than 130 people died in the fires, which destroyed more than 7,000 homes and burned more than 70,000 acres. People living in poorer, informal settlements suffered the most damage.
The researchers also did not detect a significant influence from El Niño, the natural climate pattern that warms the Eastern Pacific on a cyclical basis, sometimes for several months and sometimes for a few years at a time. The Pacific Ocean has been in El Niño formation since June.
“In this particular region, for these particular fire conditions, we found that neither climate change nor El Niño played a significant role,” said Friederike Otto, a climate scientist at Imperial College London and an author of the study, at a briefing for reporters on Wednesday.
The study noted, however, that if the planet were to warm more than two degrees Celsius above its average preindustrial temperature, the likelihood of similar fire conditions would rise. The planet has currently warmed by about 1.2 degrees Celsius.
Other recent research has found that, across central Chile more broadly, both El Niño and climate change have contributed to increasingly intense wildfires in recent years. According to a separate study published this year, six of the country’s seven most destructive fire seasons have happened within the past 10 years, with nearly three times as much land burned during 2014-23 than in 1981-2010.
Raúl Cordero, the lead author of this study, said in an interview that he disagreed with World Weather Attribution’s finding that El Niño did not play a significant role.
“El Niño is occurring a few thousand kilometers away from this particular location,” a short distance on a planetary scale, he noted.
The Chilean authorities know that they should expect hotter temperatures and higher wildfire risks during El Niño summers, and officials dedicated additional firefighting resources to the central part of the country months in advance. The extreme conditions in early February, however, made the fires “unstoppable,” said Dr. Cordero, a climate scientist at the University of Groningen in the Netherlands and at the University of Santiago in Chile.
The complication when studying the area around Viña del Mar is that it’s meteorologically unique: Temperatures on Chile’s coast are influenced by global warming and also by El Niño and by a separate cooling effect from the Pacific. Climate change has led to stronger winds there, paradoxically causing more cold water from deeper in the ocean to churn up to the surface and cool the coast.
World Weather Attribution uses climate models to compare the likelihood and intensity of extreme weather now with similar events on a simulated Earth before climate change. Because of this region’s complexity, only five climate models were able to represent the local weather well. Typically, the group’s studies would involve anywhere from 20 to 70 different models, Dr. Otto said.
Climate change is affecting this region, the researchers explained, and is producing multiple competing effects.
“At 1.2 degrees Celsius of warming, this complex pattern of trends results in neither decrease nor increase in the surface weather conditions that drive wildfires,” Tomás Carrasco Escaff, a climate researcher at the University of Chile and another author of the study, said at the briefing on Wednesday.
Factors other than weather, such as land use and management, also play a major role and could push the probability of similar wildfires higher, the researchers said. Single-species plantations of flammable pine and eucalyptus trees have replaced native, more fire-resistant ecosystems in many parts of Chile, including around Viña del Mar.
