Climate: La Niña brings temporary relief after intense period of El Niño
The projection indicates that the world is not expected to face cooling due to La Niña. Instead, a slight relief in high temperatures is expected. The uncertainty lies in the possibility of warming persisting in other oceans, as occurred in the Atlantic and Indian Oceans during El Niño. Although there is a trend for a modest decrease, global warming is likely to continue.
La Niña is characterized by cooling of the waters of the Equatorial Pacific - Photo Reproduction/NOAA
After a period of intense climatic activity marked by the El Niño phenomenon, the world now turns its attention to its opposite, La Niña. With forecasts indicating its arrival, experts expect this phenomenon to bring a momentary relief for several regions affected by the extreme conditions generated by El Niño.In Brazil, heat waves and intense rains in areas already affected are expected to be mitigated, however, drought could worsen the situation in regions such as the Pantanal.
Scientists warn that this trend does not change the picture of global warming. After a season of overheating, signs indicate that the waters of the Pacific Ocean are likely to become colder than usual. The El Niño phenomenon, which caused a series of record temperatures and extreme events in Brazil, is almost giving way to its opposite, La Niña. Marcelo Seluchi, general coordinator of the National Center for Monitoring and Alerting of Natural Disasters (Cemaden), emphasizes that the sequence of events is not ordinary and requires continuous monitoring as it unfolds.
"The planet as a whole gets hotter in El Niño years. 2023 was the hottest in known history. We have to wait a while to see what 2024 will be like with La Niña forming", comments Seluchi in an interview with DW .
What is La Niña?
La Niña is a climate phenomenon characterized by the abnormal cooling of surface waters in the Equatorial Pacific Ocean. It occurs as part of the natural climate system known as the Southern Oscillation (ENSO), which also includes El Niño. While El Niño is marked by the warming of the waters of the Equatorial Pacific, La Niña is its counterpart, associated with colder than normal temperatures in these same waters.
Temporary relief after El Niño
The El Niño phenomenon, which usually brings extreme weather conditions such as prolonged droughts, floods and changes in temperature patterns, has been particularly intense in recent months. These adverse conditions affected several parts of the world, causing significant impacts on agriculture, water availability and even extreme weather events, such as storms and hurricanes.
Before the last El Niño took hold in May 2023, the opposite phenomenon was in effect and remained active for three consecutive years (2020-2023), an extension considered unusual. During this period, a persistent drought struck, resulting in crop losses and triggering the worst water crisis in the Paraná-Prata basin in 78 years. This basin is crucial for supplying fundamental reservoirs for the production of hydroelectric energy.
Possible consequences of La Niña
While La Niña may bring some temporary relief, it is important to be aware of its own implications. In some regions, rains may be more intense than normal, increasing the risk of floods and landslides. On the other hand, areas that depend on rainfall for agriculture may face prolonged droughts, affecting food production and food security.Initially, it is predicted that the arrival of La Niña from June will result in above-average rainfall in parts of the North region, Minas Gerais and Bahia. Meanwhile, in the South region, which faced historic flooding in some areas due to El Niño, rainfall is now expected to remain below average.
Furthermore, La Niña can also influence temperature patterns in different parts of the world. While some regions may experience colder than normal temperatures, others may experience more intense heat waves. With La Niña imminent, there is the expectation that some of these climate pressures can be alleviated. While La Niña can also bring challenges of its own, such as heavy rains in some areas and droughts in others, the changing weather pattern may offer a brief respite for communities that faced hardship during the El Niño period.
The consequences of La Niña are not limited to the regions directly affected. Due to its influence on global weather patterns, this phenomenon could have ramifications on a global scale. For example, changes in the temperature of the Equatorial Pacific Ocean can affect wind patterns over large areas, impacting precipitation patterns around the world.
Significant impact of El Niño on agribusiness
In recent months, in Rio Grande do Sul, rural producers faced climate chaos considered one of the most complex ever recorded in the region.According to Alencar Rugeri, a specialist at the state's Technical Assistance and Rural Extension Company (Emater), a series of factors such as excessive rainfall, variations in light that affected photosynthesis and pollination, along with the emergence of previously uncommon diseases, resulted in in serious damage to the corn crop.
Due to the impacts of El Niño, the soybean planting period, usually starting in October, was postponed to December, causing significant planning challenges and placing producers in a delicate situation, as highlighted by the Emater expert. The effects on soybeans have not yet been fully evaluated, as this is a critical and vulnerable period, lasting approximately 130 days. This change increases the risk of several other complications, with more intense pressure from diseases, such as rust", Rugeri detailed to DW.
According to the Systematic Survey of Agricultural Production released by the Brazilian Institute of Geography and Statistics (IBGE), there is a projection of a 4.7% drop in the national grain harvest compared to the previous year. This would result in total production of 300.7 million tonnes in 2024, in contrast to the 315.4 million tonnes harvested in 2023.
Global warming
Every time the surface temperature of the Equatorial Pacific drops 0.5°C below the historical average, it is categorized as La Niña. When this variation is upward, El Niño occurs. The momentary cooling in the Pacific predicted to occur in the second half of the year does not change the global warming trend, emphasizes José Marengo, a climatologist who leads research and development at Cemaden. He emphasizes that they are different concepts: global warming is a long-term process, while La Niña is a short-term climate variability, lasting about a year.
During the last phase of this phenomenon, caused by the cooling of the Equatorial Pacific, it was observed that the global average temperature continued to increase, albeit at a slower pace. By the end of 2023, the World Meteorological Organization reported that Earth's average temperature was 1.45°C above pre-industrial levels (1850-1900).
Although we are not predicting global cooling due to La Niña, we can expect some relief from heat waves. However, it is uncertain whether warming will persist in other oceans during this event, as occurred in the Atlantic and Indian Oceans during the previous El Niño. There may be a slight decrease, but it is important to highlight that global warming continues, as noted by Marengo.
