{"id":37804,"date":"2024-08-21T10:15:17","date_gmt":"2024-08-21T08:15:17","guid":{"rendered":"https:\/\/www.wearewater.org\/insights\/climate-forecasts-awaiting-la-nina\/"},"modified":"2024-08-21T10:51:00","modified_gmt":"2024-08-21T08:51:00","slug":"climate-forecasts-awaiting-la-nina","status":"publish","type":"waw_insight","link":"https:\/\/www.wearewater.org\/en-in\/insights\/climate-forecasts-awaiting-la-nina\/","title":{"rendered":"Climate Forecasts: Awaiting La Ni\u00f1a"},"content":{"rendered":"
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In the mid-19th century, Peruvian fishermen observed changes in ocean currents and increased sea surface temperatures approximately every four years around Christmas. Associating this with the Christian tradition of the birth of the “child” Jesus, they named it “El Ni\u00f1o” (child in Spanish). This phenomenon had a second phase, cooling, which was named “La Ni\u00f1a.” El Ni\u00f1o and La Ni\u00f1a have attracted the interest of meteorologists and climatologists, who have been gathering evidence of their significant influence on global climate.<\/p>\n<\/div><\/div>\n\n

Everything is Interconnected<\/h2><\/div>

This map clearly shows the temperature differences in the tropical Pacific waters that characterize El Ni\u00f1o and La Ni\u00f1a.<\/p>\n<\/div><\/div>

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Maps of sea surface temperature anomalies in the Pacific Ocean during two particularly strong events: La Ni\u00f1a (December 1988) and El Ni\u00f1o (December 1997). \u00a9 NOAA Climate.gov, based on data provided by NOAA View.<\/p>\n<\/div><\/div>\n\n

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In 1969, the study of El Ni\u00f1o led meteorologist Jacob Bjerknes<\/strong> to link the warming of the ocean currents with the phenomenon known as the Southern Oscillation. This oscillation involves increased atmospheric pressure in the western Pacific and the subsequent weakening of the easterly trade winds. Since then, these phenomena have been collectively referred to as the El Ni\u00f1o-Southern Oscillation (ENSO).<\/p>\n

ENSO has become a key area of study in climatology, especially since the 1970s when Edward Lorenz’s numerical models began to be applied. The American mathematician and meteorologist demonstrated that all meteorological phenomena are interconnected and that small perturbations in the atmosphere can lead to significant global climate changes through the complex atmospheric and oceanic circulation systems. The famous phrase “the flap of a butterfly’s wings in Brazil can set off a tornado in Texas” illustrates this concept.<\/p>\n

One of the most relevant conclusions about the influence of ENSO on global climate is found in a study by Washington State University<\/a>, published in\u00a0 Nature Climate Change<\/a>, which shows its correlation with simultaneous drought events. After analyzing historical data, it was concluded that 68% of these droughts occur during El Ni\u00f1o or La Ni\u00f1a and that with continued atmospheric warming, the combination of ENSO episodes with simultaneous droughts will increase by 22%.<\/p>\n<\/div><\/div>\n\n

What Impacts Have Been Confirmed?<\/h2><\/div>

After decades of study, the impacts of ENSO on global climate have been well-documented. These effects are more evident in tropical belt regions, particularly concerning their influence on droughts and floods, which typically manifest inversely depending on whether it is El Ni\u00f1o or La Ni\u00f1a.<\/p>\n

Here\u2019s a summary of the impacts based on the most damaging phenomena:<\/p>\n

Droughts:<\/strong><\/p>\n