El Niño–Southern Oscillation
In geologic timescales

Evidence is also strong for El Niño events during the early Holocene epoch 10,000 years ago. Different modes of ENSO-like events have been registered in paleoclimatic archives, showing different triggering methods, feedbacks and environmental responses to the geological, atmospheric and oceanographic characteristics of the time. These paleorecords can be used to provide a qualitative basis for conservation practices.

Scientists have also found chemical signatures of warmer sea surface temperatures and increased rainfall caused by El Niño in coral specimens that are around 13,000 years old.
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