El Niño, the notorious climate disruptor, is evolving and not in a good way. Once known for its irregular but relatively short-lived bouts of weather chaos, new research reveals that both El Niño and La Niña are now persisting longer, bringing amplified and prolonged destruction to ecosystems, economies and communities worldwide.
Triggered by shifts in Pacific Ocean temperatures, El Niño and its cold-phase counterpart La Niña have long reshaped global weather drying out regions like Africa and Australia, flooding the Americas, and damaging agriculture and fisheries. The 1997-98 El Niño alone caused an estimated $5.7 trillion in global income losses.
But what’s emerging now is far more alarming.
A recent study combining fossilised coral records and cutting-edge climate models reveals a sharp rise in multi-year El Niño-Southern Oscillation (ENSO) events. In fact, these prolonged climate anomalies are now five times more frequent than they were 7,000 years ago. And scientists say human-driven climate change is supercharging this trend.
Corals, acting as natural climate archives, show that in the early Holocene, ENSO events typically lasted just a year. Today, multi-year events like the 2020–2023 La Niña “triple-dip” are becoming disturbingly common. These extended climate swings compound damage, making it harder for societies, economies and ecosystems to recover.
Computer simulations tracing ENSO over millennia support these findings. The Pacific’s thermocline – a layer separating warm surface water from colder depths – has become shallower and more stratified, helping lock these events in place longer. While this shift was once gradual and orbit-driven, the rapid warming caused by greenhouse gases is now accelerating the change.
The consequences? Expect more intense and back-to-back droughts, wildfires, floods, heatwaves, and extreme hurricane seasons. Farming, fisheries, freshwater supplies, and coastal cities are particularly at risk as these long-lasting climate disturbances stretch disaster response systems to the brink.
“This is less a scientific puzzle than a growing crisis,” scientists warn. Unlike Earth’s orbital shifts, human actions especially fossil fuel emissions can be changed. The longer we wait, the more permanent the damage.
The verdict is clear: El Niño and La Niña are sticking around longer, wreaking deeper havoc. Mitigating carbon emissions and boosting climate resilience aren’t optional anymore they’re essential. The clock is ticking on the next multi-year ENSO storm.