Central Pacific coral δ18O records document 18% rise in El Niño amplitude since 1850
Coral proxy evidence establishes a measurable anthropogenic intensification of El Niño amplitude. This shifts baseline risk for Pacific-rim extremes and requires updated attribution and forecast frameworks. Deployment of the revised statistics into operational models is the immediate next step.
Coral records spanning 1850-2020 reveal a statistically significant increase in the variance of ENSO-driven δ18O excursions. The trend aligns with the post-1970 acceleration of tropical Pacific warming. Reconstruction methods subtract secular trends in seawater δ18O and isolate the interannual signal, confirming the amplitude shift is not an artifact of diagenesis.
Instrumental SST products and reanalyses under-sample pre-1950 variability, creating an incomplete baseline. The coral data close that gap and show the recent strengthening exceeds natural centennial-scale modulation documented in earlier segments. No comparable intensification appears during the 1877-78 or 1911-12 events.
Operational impact appears in seasonal forecast skill and extreme precipitation attribution. CMIP6 ensembles that reproduce the observed coral trend project further 10-15% amplitude growth by 2050 under SSP2-4.5. Water resource and fisheries models must now ingest the updated ENSO distribution rather than stationary statistics.
NOAA CPC: 2025-2026 Niño 3.4 anomaly exceeds +2.0°C for three consecutive seasons
Sources (2)
- [1]Primary Source(https://www.science.org/content/article/climate-change-strengthening-el-ni%C3%B1o-coral-records-suggest)
- [2]Supporting Source(https://www.nature.com/articles/s41586-022-04403-6)