897. El Niño Persists Until April 2024

On July 4, the World Meteorological Organization (WMO) declared that there were signs of an El Niño event, and on November 8, it announced that this event would continue until at least April 2024 and could affect temperature increases over land and sea.

As of mid-October, sea surface temperatures and other indicators in the central and eastern Pacific Ocean are consistent with an El Niño event. El Niño is expected to develop rapidly in July and August and peak between November and January 2024.

El Niño is a phenomenon that occurs every 2-7 years and typically lasts 9-12 months. While El Niño itself is a natural phenomenon that raises sea surface temperatures near the equatorial Pacific Ocean, its impact must be considered when it occurs in the context of climate change due to anthropogenic activities.

The impact of El Niño on global temperatures is usually felt a year after the event, in this case in 2024. However, since June, record land and sea surface temperatures have already been recorded, with monthly mean sea surface temperatures in the central to eastern equatorial Pacific ranging from 0.5°C above the 1991-2020 average in May 2023 to 1.5°C above the 1991-2020 average in August 2023. It is almost certain that 2023 will be the hottest year on record, and next year could be even hotter.

The WMO Secretary General says that the impact of greenhouse gases from anthropogenic activities is undoubtedly behind this. In fact, the last record high temperature in 2016 was attributed to a combination of a very strong El Niño event and a "double whammy" of anthropogenic warming caused by greenhouse gases.

Some regions may experience increased frequency and damage from extreme weather events such as heat waves, droughts, wildfires, torrential rains, and floods. However, because El Niño events are not the only determinants of global and regional climate patterns, a strong El Niño event does not necessarily mean a strong local impact. There has never been an El Niño event that had exactly the same impact as previous ones.

Contributor: IIYAMA Miyuki (Information Program)