Recent weeks have seen signs of a historically strong El Niño global climate pattern, with deadly fires in South America and deluges in California. However, scientists are now predicting that this regime could disappear within months. The National Weather Service has issued a La Niña watch, projecting a 55 percent chance that the opposite pattern of El Niño will develop by August.
The development of La Niña would have significant consequences for weather patterns in the United States and around the world. It could also temporarily slow the rapid global warming that began about nine months ago when El Niño first took hold.
La Niña is known for encouraging active and destructive Atlantic hurricane seasons, as well as promoting dry conditions for Southern California and the Southwest. It also tends to subdue global temperatures, moderating the extreme levels of warming observed recently.
January was Earth’s warmest January on record and marked the end of a 12-month period during which the planet reached a long-feared level of warming: 1.5 degrees Celsius above a historic average from the 19th century.
The influence of La Niña or El Niño on Earth’s climate depends on conditions along the equator in the Pacific Ocean. El Niño occurs when normal trade winds weaken or reverse, causing warm water to pool along the surface of the central and eastern Pacific. Conversely, La Niña occurs when Pacific trade winds push warm waters to the west. These patterns have domino effects on weather around the world.
Climate forecasters at the Weather Service believe that El Niño will continue to weaken through the spring months, with a 79 percent chance of neutral conditions prevailing between April and June. A quick switch to La Niña after a historically strong El Niño episode is common.
The transition from El Niño to La Niña will be closely monitored by scientists to determine its effect on global average temperatures and whether it will accelerate global warming and climate change. If La Niña moderates global temperatures in 2024 and prevents them from surpassing 2023, it would support the theory that 2023 was an El Niño-driven anomaly. However, if 2024 ends up warmer than expected despite the presence of La Niña, it would indicate a systematic change.
These climate transitions also provide an opportunity for scientists to learn more about how global warming influences El Niño and La Niña. They suspect that the frequency of strong El Niño and La Niña events is likely to increase throughout the next century.
