Coarse-resolution palaeoclimate proxy evidence has suggested that the Pliocene warm period (∼3–5 million years ago) was characterized by permanent El Niño conditions in which the equatorial Pacific was uniformly warm, instead of having the modern-day 'cold tongue' extending westward from South America. This study uses high-resolution climate proxy information from fossil corals to challenge this assertion and shows that ocean conditions in the western Pacific during the Pliocene warm period were characterized by El Niño variations similar to modern-day variations.
- Tsuyoshi Watanabe
- Atsushi Suzuki
- Tomoki Kase
