Fossil fuels intensify El Niño events

Human-caused global heating from burning fossil fuels is supercharging El Niño climate patterns, a major new study has found. The research, published in the journal Science, establishes that the broader overheating of the planet is making El Niño itself more intense when it occurs.

El Niño is a naturally occurring phenomenon that happens every two to seven years, when waters in the eastern tropical Pacific Ocean heat up. The latest developing El Niño, set to peak later this year, is predicted to be the strongest in living memory and has been informally dubbed a "Godzilla" event.

"Our findings suggest El Niño can supercharge global warming but also global warming can supercharge El Niño, that is what we are seeing," said Julia Cole, a climate researcher at the University of Michigan who led the study. She stated the current trend of stronger events is not a fluke and represents a shift from patterns seen prior to industrial times.

A 1,000-Year Coral Record

Scientists reached their conclusion by analyzing the chemical composition of large, boulder-like coral fossil deposits found on the Galápagos Islands. These old corals, dating back 1,000 years, contain signatures that indicate historical sea surface temperatures. The Galápagos, situated off the coast of mainland Ecuador, is described by Cole as being "right in the heart of El Niño country."

The analysis revealed that while El Niño patterns remained fairly stable for most of that long period, changes began around the time of mass industrialization in the late 19th century. This shift has become even more extreme in the past 40 years. El Niño variability is now around 37% higher than during preindustrial times.

"After the El Niño in 1982, we start seeing much more variability." Cole said. Her team managed to rule out any random or naturally occurring reason for this switch. The consistency and distinct difference from preindustrial times surprised the researchers.

Impacts and Urgent Calls

The findings provide a strong indication that the climate crisis is already amplifying El Niño events, according to study co-author Samantha Stevenson-Karl of the University of California, Santa Barbara. If true, very large events like the one currently brewing might become more common in the future.

Such a scenario has profound impacts. As the world has heated up, a string of recent "super" El Niño events has provided extra acceleration, with intense events causing the global temperature record to fall in 1998, then 2016, and then further in 2024. The current huge El Niño could push about 50 million people worldwide into acute hunger before the end of next year due to impacts on food production.

Countries already dealing with growing incidences of heatwaves, wildfires, and flooding worsened by the climate crisis will face further strain. During El Niño, parts of South America and the southern US often face heavier rainfall and floods. In India, the monsoon season is typically reduced, while countries like Indonesia and Australia face drier conditions and droughts.

Julia Cole argues this understanding should prompt countries to ramp up adaptation ahead of such events, pointing to food stockpiling efforts like those currently underway in India. "We can prepare and try to adapt," she added. "But we also need to look at the root cause, which is the fossil fuels we are burning every day."

Andrew Dessler, a climate scientist at Texas A&M University not involved in the research, called the paper an "important validation" of model predictions. He said it underscores that a substantial share of damage from the upcoming El Niño should be linked to our fossil-fuel-driven economy. The findings reinforce the urgent need to transition away from fossil fuels to climate-safe renewable energy.