A super El Niño led to flooding in China in 1998
ROBYN BECK/AFP via Getty Images
Recent weather models suggest the potential formation of a very strong El Niño climate phase later this year, possibly the most intense on record.
Often described as a “super El Niño” or “Godzilla El Niño,” it may lead to droughts in some regions, floods in others, and could result in the hottest year on record globally.
“Current forecasts indicate the tropical Pacific is warming faster than at any time this century,” according to Adam Scaife from the UK’s Met Office. “This indicates something unusual is happening.”
What is a Super El Niño?
El Niño is a natural climate phenomenon that elevates global temperatures and disrupts weather patterns. It occurs when the trade winds over the tropical Pacific weaken, which diminishes the upwelling of cold water and allows warmer surface water to move back across the central and eastern Pacific, shifting atmospheric circulation eastward.
The onset of El Niño is marked when central Pacific sea surface temperatures rise 0.5°C above the long-term average. A temperature rise of 2°C or more signals a very strong or “super” El Niño.
The name El Niño, meaning “the Christ child,” was given by Peruvian fishers who observed the warming pattern peaking in December.
Super El Niño events are rare, having only occurred in 1982-83, 1997-98, and 2015-16.
How likely is it to happen?
Recent westerly winds have pushed significant warm water towards the central and eastern Pacific, laying the groundwork for a potentially strong El Niño. Met Office models predict a temperature anomaly nearing 2°C by September, with European Centre for Medium-Range Weather Forecasts (ECMWF) models estimating a 50% chance of reaching a 2.5°C anomaly by October.
The US National Weather Service forecasts a 25% chance of a super El Niño by year’s end. If certain European models projecting central Pacific anomalies above 3°C by September are accurate, this could be the strongest El Niño ever recorded.
However, the indicators of a developing El Niño remain weak, and models face challenges in making precise predictions due to the “spring predictability barrier.” Better insights into the strength of the upcoming El Niño will emerge in May or June.
What are the impacts on weather?
Changes in atmospheric circulation over the Pacific have far-reaching effects through long-distance “teleconnections,” altering global weather patterns. This can lead to crop failures, coral bleaching, disease spread, and significant economic damage.
“The system is disturbed, shifting from normal,” notes Tim Stockdale at ECMWF. “Rainfall might not increase, but it occurs in atypical locations.”
El Niño usually brings stormy, wet conditions to southern coasts of North and South America, the Horn of Africa, and China, increasing flood risks.
Conversely, regions like Australia, South-East Asia, central and southern Africa, India, and the Amazon rainforest may face hot, dry weather, raising the risk of droughts, heatwaves, and wildfires.
In the UK and north-western Europe, the effects are more complex. El Niño can lead to hotter summers and colder winters, or wet, mild winters, depending on other climate patterns.
Severe outcomes can persist after El Niño peaks. Following the 1997-98 super El Niño, China’s Yangtze river valley experienced devastating rainfall and flooding, resulting in 3000 fatalities, the destruction of 15 million homes, and $20 billion in economic losses.
On a positive note, fewer hurricanes form in the Caribbean and along the US east coast during El Niño. Increased atmospheric circulation causes greater wind shear, leading these storms to dissipate quickly rather than intensifying into large hurricanes.
How will it affect the climate?
If climate change is like a rising tide, gradually increasing temperatures, then El Niño acts as a giant wave, temporarily boosting them further. A strong El Niño could raise global temperatures by 0.2°C.
The last El Niño in 2024 led to the hottest year on record, with global temperatures briefly surpassing the Paris Agreement limit of 1.5°C for the first time. Should a super El Niño develop, it is anticipated that 2027 will set a new record.
“Considering we are already near 1.4, it seems likely that 2027 may exceed the 1.5 threshold,” says Scaife. “This indicates that [global warming is] approaching the Paris threshold.”
Are we going to see more super El Niño events?
While climate change is heating the central Pacific, the long-term average temperatures are also rising, so the frequency or intensity of El Niño temperature anomalies may not increase under the current definition. Consequently, the US National Weather Service now classifies El Niño based on how much warmer the central Pacific is compared to other tropical regions, though this definition is not widely adopted yet.
Occurrences of El Niño and its cooler counterpart La Niña have become more frequent and intense over the last 50 to 60 years. A study indicates climate change has heightened these warm and cool temperature fluctuations in the central Pacific by 10%. However, with only about 150 years of data and early measurements being less reliable, many scientists are hesitant to assert that climate change is intensifying El Niño.
“It’s a challenging question whether El Niño will change under climate change,” says Stockdale. “The answer is it probably will.”
What is evident is that global warming exacerbates El Niño’s impacts. Higher global temperatures increase soil evaporation and atmospheric moisture, intensifying extreme weather events like droughts and flooding.
“We refer to it as an intensification of the hydrological cycle,” Stockdale explains. “Since El Niño can significantly alter normal precipitation, climate change can amplify its effects.”
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