The Pacific is warming, and the WMO expects a very strong El Niño to persist into early 2027. But we need to be careful not to confuse cause and effect: El Niño is a natural phenomenon. The real issue is the climate El Niño is arriving in today.
There is a very simple way to tell the story that has been making the news in recent days: a Super El Niño is coming, and the planet could get even warmer.
It is an effective statement, but it tells a story that does not exist.
Because the new El Niño really is strong. The World Meteorological Organization (WMO) now considers it fully established and expects it to intensify further in the coming months, potentially reaching very strong intensity toward the end of 2026. The probability that it will persist through February 2027 is described as “close to 100%”: the highest level of certainty the WMO has ever expressed in an update of this kind.
But El Niño is not to blame for a warming planet.
In fact, the most important thing to understand is precisely this: El Niño is a natural phenomenon. It is part of ENSO, the oscillation that arises from interactions between the ocean and atmosphere in the tropical Pacific and that, roughly every two to seven years, redistributes enormous amounts of heat and alters patterns of temperature, rainfall and atmospheric circulation across many parts of the world. It is not a product of the climate crisis. The WMO itself explicitly describes it as a natural phenomenon and makes clear that it is not caused by climate change.
So the interesting question is a different one: what happens when a natural phenomenon like El Niño arrives on a planet we have already warmed?
El Niño is not new. What is new is the climatic context in which it occurs.
During a strong El Niño, heat stored in the ocean is redistributed, and some of that heat contributes to a temporary increase in global average temperature. That is why El Niño years tend to be particularly warm, and why the effect on global temperature can be even more pronounced in the year following the development of the event.
That is what we might expect this time as well. But we need to keep the cause separate from the temporary variation.
El Niño can push temperatures higher over a given period. It is not what produces long-term global warming.
To understand the difference, imagine a line that is slowly rising, with an oscillation moving up and down around it.
The oscillation is El Niño and La Niña. The rising line is global warming. Confusing the two means attributing the rising line to the oscillation.
And today this distinction is particularly important because the new El Niño is arriving while the oceans and the climate system as a whole are already experiencing exceptionally high temperatures. The WMO points out that the exceptionally warm conditions in the tropical Pacific are themselves contributing to the strengthening of the event.
The point, then, is not that El Niño has suddenly started warming the Earth. It is that El Niño is arriving on an Earth we have already warmed.
The timing of this event, alongside the United Nations’ latest statements, makes the situation even more significant.
The Limiting Overshoot report, published by UNEP on September 2, starts from a conclusion that would have been much harder to formulate until recently: exceeding the 1.5°C threshold above pre-industrial levels is now widely considered unavoidable in the coming years, given current policies and emissions trajectories. Even under the most optimistic scenario considered in the report, warming would peak at around 1.8°C.
This does not mean that “we have exceeded 1.5°C because of El Niño.”
Nor does it mean that a single year above 1.5°C automatically amounts to exceeding the Paris Agreement temperature goal. The threshold concerns long-term global warming, while individual years can be influenced by natural variability, including El Niño. 2024, for example, was the first calendar year in which global average temperature exceeded 1.5°C above the pre-industrial level, but that does not mean the Paris Agreement goal was formally breached in that year.
The distinction is anything but academic. Otherwise, we risk turning a natural phenomenon that temporarily amplifies heat into a convenient scapegoat.
The real novelty of the UNEP report is that it shifts the question.We should not ask only whether we will exceed 1.5°C. We should ask how far above that threshold we will go, how long we will remain there, and how far we will be able to come back down.
UNEP describes a pathway of overshoot, peak and decline: exceedance, peak, decline and stabilization. And it stresses that every fraction of a degree avoided, and every year spent above 1.5°C that can be shortened, reduces risks to people, ecosystems and economies.
It is an important conceptual shift: 1.5°C is not a switch.
There is no day when the planet suddenly moves from “safe” to “catastrophic.” Instead, we have a climate system in which risks increase progressively and, in many cases, non-linearly as temperatures rise and exposure continues.
And above all, eventually returning toward lower temperatures does not mean returning to the world we had before. Some glaciers, ecosystems and forms of biodiversity may suffer irreversible losses; sea levels will continue to rise for centuries; societies and territories will have to adapt to conditions that will meanwhile have become different.
That is why the idea of overshoot should not lead to resignation. It should lead to urgency.
This is perhaps the most important part of the story. El Niño is not something we can “stop”. Nor should we think of climate change as something that can be managed simply by waiting for the next natural oscillation to pass.
What we can do is reduce the warming we are adding to the system while preparing for the consequences of the warming we can no longer avoid.
UNEP is very clear on this point: mitigation and adaptation cannot be treated as two successive stages. They have to move forward together. Rapidly reducing emissions is necessary to limit the peak of warming; adapting cities, infrastructure, agricultural systems and ecosystems is necessary to reduce the damage that warming will cause.
There is another detail worth keeping in mind. The UNEP report also considers removing CO₂ from the atmosphere — through technologies and nature-based solutions such as ecosystem restoration — as part of the strategies needed for a possible return below 1.5°C. But it is equally clear that carbon removal cannot replace emissions reductions.
This distinction is fundamental: we cannot keep emitting and assume that planting enough trees will eventually erase the bill. Trees can help. Ecosystems can help. Carbon removal will have to help.
But first comes the simplest and hardest thing of all: stop adding so much carbon to the atmosphere.
The next El Niño could make 2027 an exceptionally warm year. It could alter rainfall and temperatures thousands of kilometres from the Pacific, increasing the risk of drought, flooding and extreme heat in several regions. And its intensity alone cannot tell us how severe the effects will be in any particular country: timing, geography and other climate factors also matter, including conditions in the Indian and Atlantic oceans.
But precisely for this reason, it would be a mistake to present El Niño as the cause of the problem. El Niño is part of the climate.
Global warming is the climate changing.
And today we are witnessing something much bigger than an anomaly in the Pacific: we are watching a natural phenomenon, as old as the climate system itself, moving through a world that we have made warmer.
We cannot decide whether the next El Niño will arrive. But we can decide how warm the planet will be when it does. And above all, we can decide how long we will allow warming to keep increasing.
It’s not El Niño’s fault. And that is precisely why we cannot use it as an excuse.