Ancient corals reveal intensified El Niño in equatorial Pacific since Industrial Revolution

Ancient coral skeletons are providing a long-term perspective on climate variability, revealing a significant intensification of El Niño events in the equatorial Pacific. Analysis of corals older than a thousand years shows a 36% increase in temperature variability since the pre-industrial era. This finding offers crucial insights into the natural fluctuations of this major climate pattern.

The research involved a dedicated effort to find and study these ancient coral archives. Lead researcher Julia Cole recounted the initial challenges, including the near-total destruction of Galápagos reefs by the powerful 1982-83 El Niño event. This event wiped out 90% of the reefs, ironically hindering the very study of El Niño's history that the expedition aimed to undertake.

Despite these setbacks, Cole and her team eventually located intact, ancient coral specimens starting in 2006. These corals allowed them to reconstruct the history of El Niño over more than a millennium. By combining their measurements with existing research, they have built a detailed timeline of the phenomenon's past behavior.

While the study clearly documents an increase in El Niño's intensity and variability, scientists are cautious about drawing direct causal links to current global warming trends. Establishing a definitive connection remains a complex task, requiring further research to disentangle natural climate cycles from anthropogenic influences.

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When we went, for the first time in 1989, to the Galápagos to study old corals that had been reported to us, they had disappeared. It must be said that the El Niño event of 1982-1983 had destroyed 90% of the archipelago's reefs. It's ironic because it was precisely to try to understand the history of this phenomenon that we had made the trip, hoping to read the climatic archives engraved in the coral skeletons.