Early forecasts indicate that the El Nino climate phenomenon might return later this year, potentially causing global temperatures to surpass the critical 1.5 degrees Celsius threshold for the first time.
The El Nino Southern Oscillation (ENSO) includes El Nino and La Nina—two opposing states affecting the Earth’s climate system with significant impacts on weather patterns, ecosystems, and economies worldwide.
Professor Adam Scaife from the U.K. Met Office describes ENSO as “the biggest single natural variation in climate” on a multi-year scale.
El Nino, meaning “the little boy” in Spanish, is characterized by a rise in sea surface temperatures in the tropical eastern Pacific by at least 0.5 degrees Celsius above the average. This phenomenon typically occurs every few years and can significantly influence global temperatures.
Following a prolonged La Nina period, which generally cools global temperatures, expectations are high for the return of El Nino. The last eight years have been the warmest on record, with 2016, boosted by a strong El Nino, being the hottest year ever recorded.
Professor Adam Scaife of the U.K. Met Office warns that a strong El Nino could drive global temperatures to unprecedented levels, possibly surpassing the critical 1.5°C threshold.Scaife notes that if a large El Nino develops, it could push global temperatures very close to or above the 1.5-degree threshold. This threshold is a key limit set by the 2015 Paris Agreement to avoid severe climate impacts. Predictions suggest that El Nino effects usually peak in December, but their full impact might not be felt immediately.
The current chance of an El Nino event this year is between 60% and 70%. Scaife emphasizes that the underlying warming from climate change is significant, with natural fluctuations like El Nino adding to this warming.
These fluctuations could exacerbate the current warming trend, making it likely that the first year exceeding 1.5 degrees Celsius will be an El Nino year.
Weather patterns influenced by El Nino could lead to drier conditions in Indonesia and increased drought risk in Australia, among other global impacts. The exact intensity of the upcoming El Nino remains uncertain, but its potential effects on global temperatures are closely monitored.