Experts Warn of Historic El Niño Impacts Across South America

A strengthening El Niño phenomenon is triggering severe weather patterns across South America, with some indicators suggesting it could be one of the most intense events in over 150 years. The phenomenon, caused by the warming of the Pacific Ocean, is producing contrasting effects across the continent. Heavy rains and flooding are affecting parts of Chile, the coasts of Peru and Ecuador, northern Argentina, southern Brazil, and Uruguay. Conversely, severe droughts are impacting Colombia, Bolivia, and the Amazon basin. In Chile, intense storms have already resulted in over ten deaths and thousands of displaced people.

Researchers warn that the Amazon rainforest is particularly vulnerable. A study cited by Nature indicates that the region could reach a tipping point where droughts, tree death, and wildfires cause an irreversible transition from tropical forest to degraded savanna. This collapse could release vast amounts of carbon and drastically reduce rainfall across South America. Data from the University of Beijing shows that forest moisture and biomass reached their lowest levels since 1992 during the 2023 and 2024 droughts, leaving the ecosystem less capable of resisting new extreme events. Some experts suggest the tipping point may have already been crossed due to the combined effects of deforestation and fire.

Beyond environmental degradation, the phenomenon poses risks to human health and stability. Experts note that increased temperatures and rainfall can lead to outbreaks of infectious diseases, such as cholera, and threaten food security. The U.S. National Oceanic and Atmospheric Administration (NOAA) has reported a probability greater than 90 percent for a very strong event during the 2026 and 2027 northern hemisphere autumn and winter, potentially surpassing the intensity of any event recorded since 1950.