El Niño Phenomenon Poised to Be Most Intense on Record, Potentially Making 2027 Hottest Year

The current El Niño phenomenon is shaping up to be the most intense recorded, with experts warning it could trigger extreme weather events worldwide and potentially make 2027 the hottest year in history. This episode, amplified by human-driven global warming, offers a glimpse into the temperatures that could become commonplace by the late 2030s.

El Niño is a natural climate variation characterized by the warming of surface temperatures in the central and eastern equatorial Pacific Ocean. It occurs when the prevailing east-to-west winds weaken, allowing warmer waters to shift eastward. This sustained warming of surface temperatures over several months leads to increased storm activity in the region, with cascading effects throughout the Earth's atmosphere, according to climatologist Emily Becker of the University of Miami.

The consequences include warmer, drier conditions in some areas and cooler, wetter conditions in others. Michelle L'Heureux of NOAA's Climate Prediction Center notes that stronger El Niño episodes can lead to more pronounced impacts, though these repercussions are not guaranteed. Current sea surface temperatures in the Niño 3.4 region, a key Pacific indicator, are approximately 2.6°C above the 30-year average. Projections suggest the phenomenon could peak in November at 3.9°C above average, surpassing the 3°C anomaly recorded in 2015, a previous record year.

This intensification is expected to make 2027 the warmest year on record, as El Niño's effects are typically most pronounced the year after its peak. Climatologists Zeke Hausfather and Andrew Dessler estimate El Niño could cause a global average temperature increase of 0.3°C in 2027. Dessler describes this as a preview of the future, projecting that such a long-term increase might otherwise not be expected until 2037. However, he clarifies that this warming will primarily be concentrated in the equatorial Pacific. Mike McPhaden, a researcher at NOAA's Pacific Marine Environmental Laboratory, offers similar estimates, suggesting it's conceivable that 2027 could reach 1.7°C above pre-industrial levels.