Coral records show El Niño intensifying as planet warms

Ancient coral skeletons are providing a stark warning: El Niño events are growing stronger as the planet warms, a trend with profound implications for the future of climate change. A new study published in the journal Science reveals that these powerful El Niño episodes, which drastically alter global weather patterns, are becoming more intense than they have been in the last 1,000 years.

The research comes as a strengthening El Niño in the equatorial Pacific is poised to become one of the most intense ever recorded. Scientists estimate it could peak by the end of the year, potentially leading to record global heat in 2027. The effects are already being felt worldwide, from severe droughts in Central America to intensified forest fires in Indonesia.

"We didn't know before this study, but now we know that, in the eastern Pacific, these very strong El Niños are unusual in the context of the last 1,000 years and are very much above the pre-industrial level," said lead author Julia Cole, a professor at the University of Michigan. While scientists generally agree that El Niño's global weather impacts overlap with climate change, exacerbating rainfall in some areas and drought in others, there has been less consensus on whether global warming itself amplifies the El Niño-Southern Oscillation (ENSO) cycle.

By analyzing coral skeletons from the Galapagos Islands, researchers reconstructed monthly temperature records spanning the last millennium. The chemical composition of the coral reflects the conditions under which it formed. The findings indicate that ENSO-related oscillations were considerably smaller before 1850, began increasing in the late 19th century, and showed a "striking amplification" in the last 40 years. This suggests a clear link between rising global temperatures and the intensification of El Niño events.

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We didn't know before this study, but now we know that, in the eastern Pacific, these very strong El Niños are unusual in the context of the last 1,000 years and are very much above the pre-industrial level.