Scientists are engaged in an ongoing debate over whether climate change is intensifying El Niño events, a natural climate pattern that influences global weather and temperatures. The current El Niño, which began recently and is forecasted to last through 2027, is expected to be particularly strong, potentially breaking historical records.

El Niño arises from fluctuations in ocean surface temperatures in the central Pacific, triggering widespread disruptions in weather patterns such as droughts, floods, and heatwaves. Over the past several decades, El Niño episodes have tended to be notably strong compared to those recorded in the past 600 years, prompting some researchers to argue that human-induced climate change is amplifying these events.

Several scientists cite recent trends as evidence of a climate change influence. Michael McPhaden, senior scientist at the National Oceanic and Atmospheric Administration (NOAA), acknowledges considerable uncertainty but notes that a strong El Niño this year would be remarkable. According to forecasts, sea surface temperatures in the central Pacific could rise more than 3 degrees Celsius above average, potentially producing an El Niño of unprecedented intensity.

Wenju Cai from the Ocean University of China has been among the more vocal proponents of a climate change link. In a 2023 study published in Nature, Cai and colleagues used climate models to simulate El Niño activity in a hypothetical world with pre-industrial levels of greenhouse gases, finding a less than 3 percent chance of a strong multi-decade run of intense events without human influence. Many future climate projections also predict stronger El Niño events as global temperatures rise.

However, some experts urge caution, noting limitations in both the historical record and climate models. Accurate ocean temperature data only extend back to the mid-20th century, and proxy data from corals and tree rings, while useful, cannot provide definitive measurements. Clara Deser, senior scientist at the National Center for Atmospheric Research, said the recent pattern could represent natural climate variability rather than a direct effect of warming. She characterized the evidence as inconclusive amid the inherent complexity and chaos of the climate system.

Reflecting this uncertainty, major scientific bodies have adopted cautious positions. The Intergovernmental Panel on Climate Change (IPCC) in 2021 expressed low confidence in a direct human impact on El Niño intensity or frequency. Similarly, the World Meteorological Organization (WMO) recently stated there is no current evidence that climate change is increasing El Niño events but acknowledged the debate remains unresolved.

Despite the lack of consensus, experts agree that an El Niño occurring in today’s warmer world will likely exacerbate climate extremes. The combination of hotter temperatures and a moister atmosphere is expected to intensify droughts and flooding in regions affected by El Niño-driven weather disruptions.

United Nations Secretary-General António Guterres warned that El Niño conditions will compound the impacts of global warming, amplifying hardship worldwide. As scientists continue monitoring the evolving event, understanding the interplay between climate change and natural variability remains a critical challenge with significant implications for forecasting and disaster preparedness.