Right now, a number that is uncomfortable keeps coming up in discussions among climate scientists. It is six degrees Celsius. Some subsurface water temperatures in the Pacific have already risen that much above average in some locations; the UN’s World Meteorological Organization noted this fact with considerable caution, calling it “unusually warm.” The language used by meteorologists is typically measured. When they begin to use terms like “unusual,” it’s important to pay attention.
This week, NOAA formally declared El Niño conditions to be in place, confirming what the models have been indicating for months. Given that forecasting usually becomes unreliable in the spring, the agency places the likelihood of El Niño fully developing by fall at about 90%. This is a startling level of confidence. The spring predictability barrier, which typically compels forecasters to hedge, is hardly present this year, according to Nathaniel Johnson, a research meteorologist on NOAA’s ENSO seasonal forecast team. At this point, that level of certainty is unusual in and of itself.
The arrival of El Niño is not the only thing that worries scientists. It is the result of several elements piling on top of one another. Decades of carbon emissions have already raised the planet’s baseline temperature. 2024 was the hottest year ever, largely due to the recent El Niño. Even a moderate event could result in temperature anomalies that a strong event would have produced ten years ago because another cycle is now beginning from a warmer floor. Press releases and cable weather segments don’t always translate well because of the way the math compounds.
A “very strong” event, which is defined as sea surface temperatures rising more than 2 degrees Celsius above average in the East Central tropical Pacific, has a 25% chance, according to NOAA. A few models predict temperatures that are 2.6°C above average, and at least one Canadian model indicates that temperatures could reach 3°C, which would surpass the record of 2.5°C set during the harsh 2015–2016 cycle. This specific El Niño caused famine alerts, fueled devastating fires throughout Indonesia, and exacerbated civil unrest in drought-stricken tropical regions. They are not historical footnotes. It took years to fully account for these kinds of results.
It’s difficult to ignore the extent to which public communication flattens this discourse. Online, the terms “Super El Niño” and “Godzilla El Niño“—neither of which is official—are used to generate clicks, which paradoxically makes the actual science seem like hype. A record-breaking event is unlikely, according to Berkeley Earth chief scientist Robert Rohde. However, “probably unlikely” and “not worth understanding” are quite different concepts, and public comprehension often breaks down in the space between them.
Additionally, the geographic effects are more nuanced than the majority of coverage indicates. Southeast Asia and parts of South America should anticipate hotter, drier weather with a higher risk of wildfires. The monsoon in India may become weaker. The risk of flooding is greater in the southern United States. A mild winter opening followed by a cold tail-end may occur in the UK; this pattern seems manageable until it interacts with aging infrastructure and already-stressed agricultural systems. Because no two El Niño events behave the same way, accurate forecasting is both useful and intrinsically constrained.
Fishermen have been identifying this pattern since the 1600s somewhere off the coast of Peru. Arriving around Christmas with warm, fish-depleting water, they dubbed it El Niño de Navidad, or the Christ Child. There’s something unsettling about the fact that the ocean is doing something familiar, something that has been documented for generations, and we’re still debating how seriously to take it, even though the tools are more advanced and the stakes are much higher four centuries later. The models are making a statement. Whether enough people are paying attention is the question.
