The United Nations’ World Meteorological Organization (WMO) announced on Monday that the return of the La Niña weather phenomenon should help to reduce global temperatures after several months of record-breaking heat. This cooling phase comes as the El Niño pattern, which has been contributing to extreme global temperatures since mid-2023, is showing signs of ending.
According to the WMO’s latest update, the impacts of La Niña will likely be felt in the coming months. However, the organization warns that despite the cooling trend, long-term global temperatures will continue to rise due to human-induced climate change, which exacerbates extreme weather and disrupts seasonal rainfall and temperature patterns.
La Niña is characterized by the cooling of ocean surface temperatures in the tropical Pacific Ocean, accompanied by changes in wind, rainfall, and atmospheric pressure. This phenomenon typically produces climate impacts opposite to those of El Niño, which heats ocean surfaces and leads to droughts in some regions and heavy downpours in others.
The WMO has indicated a 60 percent chance of La Niña conditions occurring between July and September, increasing to a 70 percent likelihood from August to November. The chances of El Niño redeveloping during this period are negligible.
Since the return of El Niño in June 2023, each month has set new high-temperature records, making 2023 the warmest year on record globally. Despite the anticipated cooling from La Niña, the WMO stresses that the planet will continue to warm due to heat-trapping greenhouse gases from fossil fuel use.
WMO deputy secretary-general Ko Barrett emphasized, “The end of El Niño does not mean a pause in long-term climate change, as our planet will continue to warm due to heat-trapping greenhouse gases. Exceptionally high sea surface temperatures will continue to play an important role in the coming months.”
The WMO also highlighted that the past nine years have been the warmest on record, even considering the cooling influence of a La Niña event that lasted from 2020 to early 2023. The most recent El Niño, which peaked in December, was one of the five strongest on record.
In the United States, the National Oceanic and Atmospheric Administration (NOAA) has already incorporated the expected La Niña into its forecasts for this year’s Atlantic hurricane season. NOAA predicts four to seven major hurricanes in the Atlantic between June and November.
“The upcoming Atlantic hurricane season is expected to have above-normal activity due to a confluence of factors, including near-record warm ocean temperatures in the Atlantic Ocean, development of La Niña conditions in the Pacific, reduced Atlantic trade winds, and less wind shear,” NOAA stated on May 23.
The WMO has made it a priority to ensure that all regions, particularly the least well-equipped like Africa, are covered by early warning systems by 2027. Barrett underscored the importance of seasonal forecasts for El Niño and La Niña in informing early warnings and actions globally, stating, “Our weather will continue to be more extreme because of the extra heat and moisture in our atmosphere.”
Edited by Dr. Brijendra Kumar Mishra, (Disaster Risk Reduction Expert)