Every few years, El Niño or its counterpart, La Niña, shifts rainfall across the tropics, drying Australia and flooding parts of Peru. This climatic phenomenon, part of the El Niño–Southern Oscillation (ENSO), is the largest source of yearly climate variability on Earth. However, a new study reveals that the current El Niño events are stronger than any seen in the last 1,000 years.

Scientists, including Julie Cole from the University of Michigan, reconstructed a thousand-year-long ocean surface temperature record using fossilized Galápagos corals. This limestone ‘thermometer’ showed that the intensity of El Niño events in the eastern Pacific has never been as intense as it is now, with events not resembling those from the pre-industrial era.

The Galápagos Islands, located precisely where the eastern Pacific ENSO pattern is strongest, provide a unique window into the past. With corals only found within a narrow band of longitude, the Galápagos stand out as a key location for such studies. This research adds to our understanding of how global warming may be intensifying El Niño events, a topic of ongoing scientific debate.

The findings raise questions about the potential impacts on global weather patterns and the frequency of extreme weather events. As we continue to grapple with the effects of climate change, this study serves as a stark reminder of the interconnectedness of our planet's climate systems.