El Nino conditions have developed in the tropical Pacific for the first time in seven years and the phase’s influence on weather patterns across Latin America is likely to cause periods of severe drought and intense rainfall in various parts of the region over the coming months. Abnormal rainfall distributions will have significant effects on many areas of life due to their impact on agricultural production, wildfire activity, disease outbreaks, utilities, and ultimately the economies and societies in the region.
On June 8, scientists declared an EL Nino phase of the El Nino Southern Oscillation (ENSO) had begun, which currently has a 90-percent probability of persisting through at least the rest of 2023. El Nino is one of the two extreme phases of the oscillation cycle and is a key driver of rainfall distribution patterns across many parts of the world, as well as also influencing temperatures. El Nino is associated with warmer waters in the central and eastern tropical Pacific Ocean and Latin America is one of the areas that feels the heaviest impact due to its proximity to these warmer waters. Coastal areas of northern Peru and Ecuador typically receive abundant rainfall January-May during El Nino, and though El Nino had not quite reached full swing during this period in 2023, major flood events have occurred in these areas in recent months. Authorities in Peru declared a state of emergency in 18 of the country’s 26 administrative divisions on June 8, the day El Nino was confirmed, due to the threat of flooding and landslides.
Regional Variations in Precipitation
El Nino also causes heavier than normal precipitation across much of Bolivia and northern Paraguay April-October, parts of central Chile in June (severe floods in the region June 21-23 caused at least two fatalities and affected more than 20,000 people), central and southern coastal regions of Argentina June-September, and southern Brazil, southern Paraguay, Uruguay, and northeastern Argentina September-January. Drier than normal conditions typically occur in northern Brazil April-June, northern South America June-March, western Mexico June-October, the Pacific side of Central America July-December, the Caribbean August-September, southern Chile and southwestern Argentina August, eastern Brazil September-December, and southern Peru, northern Chile, and Bolivia December-April.
In areas experiencing unusually dry conditions, agricultural yields are likely to be significantly affected. Parts of northern and northeastern Brazil, western Mexico, Colombia, Central America, and the Caribbean will likely be especially vulnerable towards the end of 2023. Crop shortages could have knock-on effects on food prices and supply chains, which could in turn lead to inflation and other economic issues which could place additional scrutiny on governments.
Secondary Impacts of El Nino Weather Extremes
Extended periods of drought may also lead to electricity supply shortages as lower river levels could lead to a lack of water in dam reservoirs; Brazil, Colombia, and Venezuela are among the countries that rely heavily on hydroelectricity. Maritime routes may also be affected; the Panama Canal already placed restrictions on large vessels due to shallow waters caused by drought in June 2023 and the issue could become more acute with drier than normal conditions likely in Panama through the rest of the year due to El Nino.
Flooding and landslides could cause widespread disruptions in areas where excessive rainfall occurs, with the most vulnerable settlements likely to be lower income districts built on hillsides or floodplains on the outskirts of towns and cities. Closures to key highways due to floods or landslides can cause supply chain disruptions, especially in remote areas where there are few alternative routes. Pools of stagnant water following floods can lead to an increase in water- and insect-borne diseases, such as cholera and dengue fever. However, in some areas the change in rainfall distribution could bring more positive effects, such as likely above-average rainfall in drought-stricken areas of Argentina. The rains will undoubtedly be a boost for struggling farmers in the normally fertile Pampas Region following months of below average precipitation.
El Nino is generally associated with hotter temperatures compared to the neutral or La Nina phase of the ENSO. Global temperatures are on average around 0.2 C (0.4 F) above average during El Nino. When we also factor in the 1.1 C (2.2 F) increase in global average temperatures that has been attributed to climate change, many scientists are predicting either 2023 or 2024 (or possibly both in sequence) could be the hottest years on record. The impacts of the increased heat are likely to be especially felt around the turn of the year. High temperature episodes are particularly likely in parts of central and southeastern Brazil. Warmer and drier conditions will likely lead to increased wildfire activity in parts of the region. Wildfires in dry areas and flooding in saturated areas can pose further threats to electricity supply infrastructure and supply chains due to possible damage to utility networks and highway closures.
El Nino’s extreme impacts on rainfall distributions and temperatures are likely to have far-reaching consequences over the coming months, both in terms of supply chain disruptions and impacts on the wellbeing of citizens. This will place additional strains on governments at a time when the political landscape is already relatively volatile across much of the region.
