After a four-year absence, he is likely to return. According to estimates released by the World Meteorological Organization (WMO) on Wednesday, March 1, there is a greater than 50 percent chance that El Niño will reappear in the South Pacific by next August. It will cause meteorological disturbances especially off the coast of Peru and contribute to global temperature increases. El Niño and its counterpart La Niña correspond to oceanic anomalies that alter the temperature of waters in the equatorial Pacific Ocean. Normally, the temperature difference between warm water in the west and cold water in the east leads to a difference in air pressure that favors east-west winds. Warm water is sucked into the Asian part of the South Pacific, while in the east deep cold water rises and cool surface water emerges along the long edge of the South American continent. In the west, heat is accelerating the evaporation of surface water, so humidity is transferred from the ocean to the atmosphere, causing heavy precipitation and favoring cyclones. La Niña is the name for a particularly severe version of the phenomenon, when surface water in the east is colder than usual. El Niño, which occurs every 2 to 7 years, describes the opposite phenomenon. The drop in atmospheric pressure over the South Pacific weakens east-west winds and even reverses them. As a result, warm surface water flows back east and brings storms and precipitation along the South American coast. Temperature increases of more than 1°C can also have an impact on fishing as fish avoid water that is too hot and nutrient-poor. El Niño events occur every 2 to 7 years and last for 6 to 18 months. They reach their peak intensity around Christmas, hence the name (El Niño means little Jesus in Spanish). The last low-intensity events occurred in April and May 2019. But El Niño can have catastrophic natural consequences over large geographic areas. In 1997, a particularly severe event caused massive fires in Southeast Asia and Australia, heavy rains in California and Central America, and severe drought in Brazil. The global average temperature increased that year, and the equatorial Pacific Ocean generally experienced an unusually long La Niña phenomenon since September 2020, which intensified the drought in the Horn of Africa and parts of South America and Southeast Asia and Oceania, causing heavy rainfall. According to experts from the World Meteorological Organization, the phenomenon is coming to an end. Even if they remember that it is too early to predict with complete reliability, if El Niño returns, it will combine its effects with those of global warming. “Despite the past eight years being the warmest on record, the cooling effect of La Niña has temporarily halted the widespread rise in temperatures,” explained WMO Secretary-General Professor Petteri Taalas in his report. If we were now entering an El Niño phase, we could experience new peaks in global temperatures. The previous record was set after such an event in 2016. According to the WMO, there is a 93% chance of being broken by 2026. ——–