Increased ENSO sea surface temperature variability under four IPCC emission scenarios

Sea surface temperature (SST) variability of El Nino-Southern Oscillation (ENSO) underpins its global impact, and its future change is a long-standing science issue. In its sixth assessment, the IPCC reports no systematic change in ENSO SST variability under any emission scenarios considered. However, comparison between the 20th and 21st century shows a robust increase in century-long ENSO SST variability under four IPCC plausible emission scenarios. Sea surface temperature variability of the equatorial Pacific Ocean dictates the strength of El Nino-Southern Oscillation events. CMIP6 models under four IPCC emission scenarios show increased variability in the 21st century from the 20th century.

Automated summary

Sea surface temperature (SST) variability of El Nino-Southern Oscillation (ENSO) plays a crucial role in its global impact. The IPCC's sixth assessment shows that there is no systematic change in ENSO SST variability under different emission scenarios, but there is a robust increase in century-long ENSO SST variability under various IPCC emission scenarios. Models indicate increased variability in the 21st century compared to the 20th century.