Are we in for a super El Niño this year? Early projections say maybe, and this worries climate scientists

After a year and a half of La Niña conditions, it looks like we could end up with an El Niño later this year. And early models suggest it could be a strong one, which could push global temperatures to record highs.

La Niña and El Niño are part of a larger, natural cyclical cycle called the El Niño Southern Oscillation (ENSO), which occurs in a specific part of the Pacific Ocean. 

La Niña brings cooler temperatures in that region of the ocean — called Niño 3.4 — while El Niño brings warmer temperatures.

But this also affects climate and weather patterns around the world — it can bring floods to some regions and drought to others — as well as impacting global temperatures.

Currently, we’re in a La Niña advisory/El Niño watch, with the National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Center calling for a period of neutral conditions before it transitions to an El Niño by the summer.

Zeke Hausfather of Berkeley Earth, a non-profit climate analysis organization, recently looked at 11 models that had a total of 433 forecasts, and found that there is a chance that we could be looking at a strong to perhaps even “super” El Niño this year.

“What was interesting is they all — or almost all, I should say — show a strong likelihood of a strong El Niño event developing later this year, which was a pretty big change from what we saw a month ago,” he said.

“It seems like we’re in for a strong [El Niño] with a chance of a super strong El Nino event. Something that could even challenge what we saw in 2015-2016.”

The strongest El Niños we’ve had in the recent past were in 1997-98 and 2015-16. The former was considered a super El Niño event, with temperatures in Niño 3.4 reaching roughly 2.7 C above average. The 2015-16 event was considered strong, with ocean temperatures reaching roughly 2 C above average.

At the moment, an average of Hausfather’s 11 analyzed forecasts is calling for a 2.4 C temperature anomaly.

Hausfather notes, however, that the projections are still early and within what scientists call the “spring unpredictability barrier,” where the forecasts are less reliable. 

Daniel Swain, a climate scientist with University of California Agriculture and Natural Resources, has looked at many of the models himself, and he says it looks like we’re in for a strong El Niño.

“The vast majority of [the models], almost all, suggest at least a moderate strength El Niño by later this summer, and the majority really do go all the way into strong or extreme territory,” he said. But he also had a caveat with the early projections: “That is perhaps the single most likely outcome, but with wide error bars.”

However, Swain noted that, at the moment, the conditions are fairly favourable for a strong El Niño.

Because our oceans trap roughly 90 per cent of excess heat from greenhouse gases, when an El Niño develops, it releases some of that stored heat into the atmosphere, which then causes global temperatures to rise beyond what is natural and beyond what human-caused warming has produced from greenhouse gases being pumped into the atmosphere.

But it also affects regional weather patterns.

At the moment, most of the models suggest that an El Niño will develop around June, though some models — including the Canadian one — diverge and suggest some weakening. The peak of the El Niño is forecast to occur in November.

This year is currently on track to be the second warmest on record, according to Hausfather, but could end up between the warmest and fourth warmest. “But El Niño tends to cause a global temperature increase a bit after,” he said. 

Typically, he said, there’s a lag of around three months. So if El Niño peaks in November or December, we’d see that temperature effect in 2027.

However, the last strong El Niño in 2023-2024 threw a curveball at climate scientists. Instead of seeing the warming beginning three months after El Niño peaked, it began in the second half of 2023, with several monthly temperature records being broken. 

Scientists are still trying to understand why that happened — and watching out for whether it could happen again.

“If we start seeing a giant peak [in temperatures] this summer, it will be very unusual and we’ll have to re-evaluate a little bit of how anomalous what happened three years ago was,” Hausfather said. “I don’t think it will [happen], but we’ll see.”

If there’s a strong El Niño, 2027 is likely to beat out 2024 as the hottest year on record, which was 1.5 C above the pre-industrial average, according to NASA. 

Swain says 2027 may be closer to 1.6 C warmer. “And so we will see 1.6 C warming level impacts in terms of extreme events globally, in terms of extreme heat, and extreme precipitation, and extreme drought, and wildfire and all of that,” he said.

“And it will be El Niño-flavoured. So some regions will see certain types of extremes, and others will see different types of extremes.”

The 2015-2016 El Niño brought with it a record hurricane year in the central North Pacific, severe drought in Ethiopia, and created conditions for the spread of disease.

2024 ‘virtually certain’ to be warmest year on record

As global temperatures continue to rise — the 10 hottest years have all occurred in the last 10 years — there’s a real concern that we may soon surpass the 1.5 C threshold of warming as outlined by the Intergovernmental Panel on Climate Change (IPCC).

According to the World Meteorological Organization, the past 11 years have been the warmest on record, with the last three years surpassing 1.5 C.

That doesn’t mean we’ve surpassed the IPCC’s threshold just yet. It will take several years of 1.5 C of global temperatures for that to happen.

But Swain said that a strong El Niño event is like a temporary window into the future. And it’s not a good one.

“In a warming climate, what a strong El Niño event does is it gives us a preview of the future that we haven’t experienced in all of human history,” Swain said.