La Niña may be coming for a visit, World Meteorological Organization says

The World Meteorological Organization (WMO) announced on Wednesday that La Niña conditions could emerge in the December 2024-February 2025 period, according to The Indian Express. Despite this possibility, scientists believe that the arrival of La Niña will be "insufficient" to counteract the warming caused by record levels of greenhouse gases in the atmosphere, as reported by Devdiscourse.

"2024 started out with El Niño and is on track to be the hottest year ever recorded," said WMO Secretary-General Celeste Saulo.

La Niña is a naturally occurring phenomenon wherein the sea surface temperatures along the equatorial Pacific Ocean fall below average. It is one of the three El Niño Southern Oscillation (ENSO) phases: negative (La Niña), neutral, and positive (El Niño). In general, La Niña produces large-scale climate variations opposite to those associated with El Niño, including significant cooling of the equatorial Pacific, according to France Info.

The WMO had previously estimated a 60% probability of La Niña occurring during the period from December to February, as noted in their September bulletin, France Info reports. In its latest forecast, the WMO announced a 55% chance of La Niña conditions developing by the end of February, down from the previous forecast, and it is expected to be short and of low intensity, UOL reports.

Strong westerly wind anomalies observed during September and early November are responsible for the slower development of La Niña, which are climatologically unfavorable for its development, according to UOL.

Multiple weather models have been predicting the emergence of La Niña since July this year, but all of them have been significantly inaccurate.

The WMO reminds that natural climate phenomena, such as La Niña and El Niño, occur "in a broader context of climate change" related to human activities, "which is raising global temperatures, intensifying extreme weather and climate conditions, and altering seasonal patterns of precipitation and temperatures," as reported by ABC Color.

Earlier this year, an El Niño was still detectable. El Niño influences winds, air pressure, and rainfall, thereby affecting the weather in many parts of the world. It increases the global average temperature, and 2024 is on track to be the hottest year ever recorded, according to Stern.

This week, the Copernicus observatory, linked to the European Union, released the forecast that 2024 is expected to be the hottest year in history, and it is already practically certain that 2024 will be the hottest year since records began, UOL reports. According to scientists from Copernicus, calculations made after consolidating data for the month of November indicate that it is impossible for the previous record, reached in 2023, not to be surpassed by the current year, UOL adds.

"Despite the absence of El Niño or La Niña conditions since May, we have witnessed an extraordinary series of extreme weather phenomena, including record rainfall and floods that have unfortunately become the new norm in the context of climate change," said Saulo.

The WMO states that ocean surface temperatures are expected to remain above average, with the exception of the area near the eastern equatorial Pacific Ocean, contributing to above-average temperatures in almost all land areas of the planet. Consequently, above-average temperatures are expected in almost all land areas of the planet, UOL notes.

This article was written in collaboration with generative AI company Alchemiq