El Nino could be strongest in decades, WMO warns

The current El Nino could become the strongest since comparable monitoring began four decades ago, the World Meteorological Organization said on September 3, warning that it is expected to intensify into a very strong event in the months ahead.

The United Nations climate agency said El Nino was firmly established and was near certain to persist through February. WMO chief Celeste Saulo told reporters in Geneva that if the current path continues, it “may be stronger than anything since our monitoring began”.

The WMO said El Nino is expected to peak toward the end of the year, though its climate impacts could continue well into 2027. The agency warned of shifting rainfall and temperature patterns, with associated risks of floods, drought and extreme heat.

El Nino warms surface temperatures in the central and eastern equatorial Pacific Ocean and can change wind, pressure and rainfall patterns around the world. The WMO said heat in the oceans releases more slowly into the atmosphere, pushing up global temperatures the year after El Nino develops.

Saulo said the powerful 2023-24 El Nino contributed to 2024 being the warmest year on record, and added that “we should not be surprised if this record is broken”. UN Secretary-General Antonio Guterres said sea surface temperatures and global temperatures were rising and that the world was in the “danger zone of extreme weather”.

The WMO said forecasts for September to November showed an increased likelihood of above-normal temperatures across almost all land areas. It said the central eastern equatorial Pacific sea surface temperature index rose from an average 1.5C above normal between May and July to weekly values of about 2.2C to 2.6C above average from late July to mid-August.

The agency said an average forecast points to the anomaly peaking at plus 3.6C, above the last two very strong El Ninos in 1997-98 and 2015-16. In some areas, subsurface ocean temperatures were more than 8C above average during July and early August.

Saulo urged disaster management authorities and climate-sensitive sectors including agriculture, fisheries, health, energy and water to prepare. The UN's International Organization for Migration appealed for $110 million to protect 4.9 million people from the potentially severe impacts of the phenomenon.

El Nino is a naturally occurring phenomenon and is not caused by climate change. Scientists expect it to worsen heat on a planet already warming from burning fossil fuels and to amplify weather extremes.