When we talk about El Niño we are not referring to a simple period of good weather or a few unseasonably hot days. In climatology, theENSO (El Niño-Southern Oscillation) is the most powerful driver of interannual climate variability on the planet. As a rule, the phenomenon recurs every 2-7 years with a moderate intensity. There have been times in history, however, when this ocean giant transformed into a “Super El Niño”capable of alter global atmospheric circulationdestroy ecosystems and cause severe humanitarian crises.
The latest projections and forecasts for the coming months describe the arrival of a potentially gigantic El Niño for thewinter 2026-2027 in the world and with possible effects also in Italy, destined to last until the beginning of next year. How does this new event compare to those of the past? To understand it, we need to analyze the history of major events and understand why the human footprint is changing the rules of the game.
1876-1878: the climate catastrophe that starved the world
Before the advent of satellites and mathematical models, the Earth was hit by an event of historic proportions. Between 1876 and 1878, an unprecedented thermal anomaly in the Pacific combined with other oceanic indices, triggering a sequence of simultaneous extreme weather events.
- The dynamics: the blocking of the trade winds stopped the rise of cold and nutrient-rich waters along the coasts of Peru (upwelling), eliminating fishing and local marine fauna.
- The global impact: the world atmospheric circulation was greatly disrupted. India, China, Brazil and Ethiopia were hit by the total absence of monsoons and multi-year droughts.
- The consequences: this single event caused one of the most severe famines in human history, with an estimate of more 30 million victims in tropical and subtropical countries.
1982-1983 and 1997-1998: Monsters of the Modern Era
With the development of the satellite network and ocean buoys, the scientific community has been able to directly measure the devastating force of modern Super El Niños.
- 1982-1983: surface temperatures in the equatorial Pacific rose by more 2°C above average. South America was overwhelmed by record rainfall and floods, while Australia and Indonesia fell into a historic drought culminating in the dramatic Australian fires.
- 1997-1998 (The “Niño del Secolo”): recorded thermal anomaly peaks exceeding +2.5 °C. It caused very violent typhoons in the Pacific, heavy flooding in the Americas and the first truly global coral bleaching crisis, with damage estimated by the IPCC at over 35 billion dollars.
2015-2016: the first real collision with anthropogenic warming
The “Super El Niño” of 2015-2016 marked a fundamental turning point for climatology: it was the first major event to unfold on a planet already significantly warmer than in the pre-industrial era due to greenhouse gas emissions.
- Duration and extension: lasted well 19 monthsbrought global average temperatures in 2016 to a historic record that remained unbeaten for years. The surface waters of the equatorial Pacific have risen by over 2.5°C compared to the long-term average, with local peaks that in some areas exceeded 3.0°C
- Ecological damage: the combination of the heat released by El Niño and the background thermal increase caused the destruction and bleaching of the 29% of corals in the northern section of the Australian Great Barrier Reef.
The historical effects of Super El Niño in Italy: what happened in past cases
While El Niño whether a phenomenon originating in the equatorial Pacific, its ability to alter global atmospheric circulation it can also indirectly influence the Mediterranean basin.
By analyzing the historical data of the most powerful Super El Niño events of the past, a picture emerges of concrete and sometimes opposite impacts on the Italian territory: in the two-year period 1982-1983the phenomenon triggered a scorching summer in the Center-South with record peaks that exceeded +44°C/+46°C in Sicily and Sardinia and severe drought in Tuscany, while the North was split by sudden violent storms (MeteoTuscany / regional historical data).
The “Niño of the century” of 1997-1998 instead it brought an exceptionally mild winter and almost free of snow in our mountains, a forerunner for a summer of suffocating and prolonged heat. More recently, in 2015-2016the effect was evident with one of the warmest and driest winters in Italian history, followed however by a cooler and more unstable summer in the Centre-North, confirming how this phenomenon in the Mediterranean does not just mean a hot summer, but above all great unpredictability and extreme weather peaks.
Comparison with today: why is the event likely to be more intense towards 2027? What will the effects be in Italy?
By comparing historical data with current trends provided by international agencies such as NOAA And WMOsubstantial differences emerge in the way in which the phenomenon is being structured in the coming months:
- The anthropic trigger factor: compared to the events of 1876 or 1997, the new El Niño is grafted onto Global ocean temperatures already at record highs. It is no longer just a natural Pacific oscillation: the phenomenon acts as an amplifier on an atmospheric system overloaded with thermal energy due to greenhouse gases.
- Increased probability of extreme weather events: scientifically it must be remembered that El Niño works in terms probabilistic and non-deterministic. It does not guarantee a single specific weather event with 100% certainty, but it dramatically increases the statistical probability of severe anomalies. With a warmer ocean base, the stored potential energy is greater, yielding potentially more violent thermal contrasts when disturbances or cyclones are triggered.
- Prolonged temporal persistence: the oceans’ ability to retain heat for longer periods is extending the estimated duration of this event to February 2027. Such a long period of weathering risks overlapping multiple seasonal cycles, increasing the likelihood of prolonged dry spells in key agricultural markets and new heat waves on the continents.
It is good to remember that, for our Peninsula, we always talk about probable trends and not mathematical certainties: El Niño will not directly affect the Mediterranean, but will alter its general atmospheric circulation.
Specifically, the highest probability is that of a winter 2026-2027 milder than normalwith snow confined almost only to the high altitudes of the Alps and a greater quantity of water vapor that could fuel it intense rainfall and extreme events in the Centre-North. In the South and on the Islands, however, the risk of unseasonal heat waves and phases of drought, dictated by the greater intrusiveness of the African anticyclone. Finally, the high temperatures of the Italian seas could accumulate potential energy, raising the probability of marine heat waves and increasing the risk of violent phenomena during seasonal changes, with strong repercussions on agriculture and water reserves.
Understanding the history of Super El Niños shows us that the planet has already faced phases of profound climate upheaval. The substantial difference today lies in the speed with which human activity is altering the starting point of these atmospheric giants.
