The child who warms the world

The name is ancient. Peruvian fishermen called it El Niño de Navidad, “the Christmas child”, because warmer waters appeared along the eastern Pacific coast around the Christmas period.

Today, that same name identifies one of the most closely monitored climate phenomena in the world.

During an El Niño event, the trade winds weaken and a greater amount of heat remains concentrated in the eastern Pacific.

The surface temperature of the ocean rises, changing the way energy and moisture are distributed in the atmosphere. It is an alteration that may seem limited, at least when observed through numbers alone, but one that can influence climate systems very far from one another.

The most recent projections from NOAA, the National Oceanic and Atmospheric Administration, indicate a high probability that El Niño conditions will develop during 2026. However, the intensity of the event remains uncertain.

This distinction is important: in public debate, probability and certainty often tend to overlap, whereas in climatology they represent two different levels of interpretation. A phenomenon can be considered plausible without its effects being predictable with precision.

In Europe, for example, the connection with El Niño is relatively weak compared to regions bordering the Pacific. The phenomenon does not automatically lead to hotter summers or rainier winters, and its effects on the European continent tend to be indirect and less evident. 

In other parts of the world, however, the signal is much clearer. Along the coasts of South America, rainfall and flooding may increase, while Australia, Indonesia and parts of southern Africa may face drier-than-normal conditions.

The same climate anomaly can therefore produce very different effects depending on where it occurs.

When talking about El Niño, the focus often tends to be on weather maps or ocean temperature anomalies. The indirect consequences are observed less often.

The 2015 - 2016 event, one of the most intense ever recorded, was associated with reductions in agricultural production, food crises in some areas of southern Africa, and alterations to marine ecosystems along the Pacific coast. In other contexts, similar phenomena have contributed to increased pressure on healthcare systems or have affected the availability and prices of certain food commodities.

Moreover, the effects do not remain confined to the territories directly affected. Some studies published in recent years estimate that major El Niño events can generate global economic impacts in the order of trillions of dollars over time. This is not only due to the immediate damage caused by floods or droughts, but also to the indirect consequences on agricultural supply chains, international trade, labour productivity, and the economic stability of entire regions.

It is one of the less intuitive aspects of the phenomenon: a temperature anomaly in the Pacific Ocean can propagate economic effects far beyond the place where it occurs.

Climate effects, after all, are rarely distributed proportionally.

With the same phenomenon, outcomes change depending on the starting conditions. The quality of infrastructure, access to water resources, economic stability, and the adaptive capacity of territories all matter. In many cases, vulnerability already exists, and the climate event acts as an additional source of pressure.

Perhaps this is the most relevant aspect. The real news, in fact, is not only the possible return of El Niño, but the context in which it could occur. 

The 2023 - 2024 event unfolded on a planet that was already warmer than in the past, contributing, together with human-induced global warming, to the temperature records observed in recent years. This means that every new climate oscillation now takes place within a system that has already lost part of its room for balance. 

Soils are exposed to more frequent water stress, many ecosystems show a reduced capacity to recover, and some infrastructure continues to be designed on the basis of climate conditions that are changing.

El Niño does not create these fragilities: it encounters them at a different stage than a few decades ago. For this reason, the issue is not only the arrival of a new climate phenomenon, but the ability of territories to absorb its effects.

The same atmospheric anomaly can produce different consequences when it occurs in systems with different levels of resources, time and room for adaptation.

This time, the child arrives in a world that is not simply warmer. 

It arrives in a world that, in many cases, has also become more vulnerable.

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