Record-Breaking Rainfall in 2024 Linked to Climate Change and El Niño
In a year marked by unprecedented weather patterns, 2024 shattered previous records with extreme rainfall. This phenomenon, influenced by both climate change and the El Niño effect, has surpassed historical rainfall levels by 20%, according to recent research conducted by UCLA.
UCLA climate scientist Chad Thackeray highlighted that “between El Niño and climate change, 2024 set a global record for the number of days with heavy precipitation.” This year’s intense weather conditions have set the stage for potentially even more extreme events in 2027.
Historically, strong El Niños have been rare, occurring only four times in the past four decades. However, the 2024 El Niño event stands out not only for its strength but also for its extensive impact. Thackeray, a researcher with UCLA’s Center for Climate Science, noted that 2024’s extreme rainfall exceeded the baselines set by past significant El Niños in 1983, 1998, and 2016.
The study, published Oct. 9 in Science Advances, revealed that while El Niño’s influence diminished over the year, climate change continued to drive extreme precipitation globally. This pattern deviated from previous years where heavy rains primarily occurred early in the year and waned as the Pacific cooled. In contrast, 2024 witnessed a resurgence of severe rainfall in August.
Thackeray explained, “That surge in 2024 is largely tied to climate change.” He pointed out that the current climate, with decades of accumulated warming, allows the atmosphere to hold more moisture, resulting in more severe rainstorms. Projections indicate that by midcentury, rainfall events similar to those of 2024 could become almost biennial.
Ocean Warming’s Role in 2024’s Rainfall
El Niño conditions in 2024 accounted for only 20% of the record rainfall, while climate change was responsible for 40%. A rare occurrence of simultaneous warming in the tropical Atlantic, Indian, and Pacific Oceans also contributed. This triple-ocean warming had only been observed at comparable levels in 1998, which previously held the record for extreme rainfall.
Thackeray commented on the rarity of this phenomenon, emphasizing that the study’s analysis focused on ocean temperatures from December to February, when El Niño is most potent. He noted, “Our analysis relied on ocean temperature measurements from December to February each year when El Niño is strongest, so we don’t yet know whether that will be a factor this upcoming year.”
Looking ahead, researchers suggest that the conditions observed in 2024 could repeat in 2027, potentially setting new records. The developing El Niño is expected to peak in the upcoming winter and might be among the strongest recorded, according to Alex Hall, senior author and director of UCLA’s Center for Climate Science.
“The El Niño now developing is expected to peak this winter and could become one of the strongest on record,” Hall stated. He elaborated on how a strong winter El Niño can set the stage for increased global precipitation extremes in the following year, especially in today’s warmer climate.
Although it’s uncertain whether 2027 will surpass 2024’s rainfall record, Hall noted that the factors are aligning for another year of significant precipitation extremes.
The study received funding from the National Science Foundation and the U.S. Department of Energy.
Original Story at newsroom.ucla.edu