El Niño: Understanding the Climate Phenomenon and Its Impacts in Latin America

The 2026 El Niño phenomenon is already making its presence felt across Latin America, raising concerns among authorities, businesses, and scientific organizations. Dr. Ken Takahashi Guevara, a principal scientific researcher at the Peruvian Geophysical Institute, provides insights into this complex climate event, its historical context, and its potential impacts on the region. ## Origins and Definition of El Niño El Niño is a multifaceted phenomenon, but its primary characteristic is the abnormal warming of the Pacific Ocean's surface. The most widely monitored region for this warming is the "Niño 3.4" area in the central Pacific, though different countries may prioritize other regions based on their specific vulnerabilities. For instance, Peru tracks both the central Pacific and the coastal region known as "Niño 1+2," as warming in these areas can lead to contrasting effects-droughts in the Andes and Amazon, or devastating floods along the coast. Historically, El Niño was named after the warm ocean current that appeared along Peru's northern coast around Christmas, hence its association with the "child Jesus." The phenomenon's impacts are diverse, ranging from heavy rainfall to severe droughts, depending on the region and the specific conditions of the event. ## El Niño and Climate Change: A Complex Relationship While El Niño and climate change are distinct phenomena, they can interact in ways that amplify their effects. The warming of the Pacific Ocean due to El Niño is superimposed on the long-term trend of global warming, making it crucial to distinguish between the two. Scientists adjust their indices to account for climate change, ensuring that El Niño's impacts are not overestimated. However, the combination of El Niño and climate change can lead to extreme conditions. For example, the 2023-2024 El Niño, combined with global warming, contributed to a record-breaking drought in the Amazon, resulting in unprecedented wildfires. Similarly, the heat along Peru's northern coast during El Niño can become more intense, posing significant risks to human health. ## El Niño vs. La Niña: Opposite Phases, Opposite Effects La Niña, the counterpart to El Niño, represents the cooling phase of the Pacific Ocean. The naming convention stems from the need to describe the opposite of El Niño, with "La Niña" eventually becoming the accepted term. While El Niño and La Niña are roughly symmetrical in the central Pacific, their effects on coastal regions like Peru are not. El Niño can bring intense warming and heavy rainfall, whereas La Niña's cooling effects are less pronounced. The impacts of these phenomena are generally opposite: El Niño may cause increased rainfall in one region, while La Niña leads to reduced precipitation in the same area. Understanding these patterns is essential for predicting and preparing for their consequences. ## Regional Impacts: Droughts and Floods El Niño's effects vary widely across Latin America. In some regions, it brings severe droughts, while in others, it triggers catastrophic flooding. The predictability of El Niño, thanks to advanced climate models, allows scientists to forecast these impacts months in advance. However, not all climate variations are attributable to El Niño; local factors also play a significant role. For example, Chile, Argentina, Peru, Ecuador, and Colombia are already experiencing the early effects of the 2026 El Niño. The peak of these impacts is expected between October and February, according to regional authorities. Understanding the nuances of El Niño and its interactions with other climate factors is crucial for mitigating its adverse effects on wildlife and ecosystems.