This year’s El Niño event has already set new temperature records and may become the strongest in at least a millennium, according to climate experts. El Niño is a natural climate phenomenon characterized by the warming of surface waters in the eastern Pacific Ocean, which disrupts weather patterns across the globe, often leading to higher temperatures, droughts, and floods.
Typically occurring every three to seven years, El Niños influence rainfall and temperature in regions far beyond the tropical Pacific. The current event follows closely on the heels of the 2023-24 El Niño, highlighting an unusually short interval between significant occurrences. Climate scientist Professor Mat Collins of Exeter University notes that while El Niño is a separate phenomenon from human-driven global warming, the two factors interact in ways that increase climate extremes. Rising baseline ocean temperatures due to global warming amplify the impact of El Niño, though separating the individual contributions of each remains challenging.
Sea surface temperatures in the critical El Niño region have already matched the record high last seen in 2015, with some forecasts suggesting temperatures could reach 4°C above average by the end of the year—levels not previously observed. Collins describes this event as potentially a “godzilla” El Niño due to its unprecedented intensity. However, he cautions that ongoing warming trends complicate direct comparisons with past events.
The expected impacts of this El Niño are widespread. Earlier effects include a weakened Indian monsoon and rising temperatures around the Pacific Rim. Further consequences may entail increased wildfires in Indonesia and severe drought conditions in the Amazon rainforest. In the United Kingdom, meteorologists anticipate wetter conditions during autumn and winter and drier, colder weather in spring, though Collins points out the difficulty in predicting UK weather with certainty.
Recent heatwaves and wildfires seen in Europe, Canada, and the United States are likely influenced more by global warming and atmospheric circulation patterns than by El Niño, as these events occurred before the El Niño’s full development. The delayed nature of El Niño’s influence means its effects typically manifest several months after its onset.
While warming ocean surfaces increase the likelihood of stronger El Niño events, the intensity also depends on temperature contrasts with other ocean basins such as the Atlantic and Indian Oceans. These variations influence the distribution of rainfall and storm activity, with the potential for more concentrated and severe weather in certain areas.
Some scientists have proposed geoengineering approaches, such as altering cloud cover in the eastern Pacific to cool sea surface temperatures and potentially weaken El Niño events. However, the effectiveness and risks of such interventions remain uncertain, given the deep ocean heat reservoirs that fuel these cycles.
Collins emphasizes the importance of improved monitoring and forecasting capabilities, which now allow for predictions of El Niño events six to nine months in advance. This advance notice helps governments and communities prepare, particularly in vulnerable regions where agriculture and infrastructure may be severely affected.
Looking ahead, climate models project that El Niño events will trigger more intense and disruptive rainfall and temperature patterns as global warming continues. The combination of El Niño and ongoing climate change poses significant challenges, especially for poorer countries already coping with environmental stressors. Reducing greenhouse gas emissions remains the primary strategy for mitigating long-term risks associated with El Niño and broader climate variability.