Climate change: Eastern Pacific surface temperature changes may be detectable by 2030

Ocean surface temperature differences over the eastern Pacific, associated with anthropogenic climate change, are projected to be detectable by 2030 — up to several decades earlier than previously thought — suggests a Nature Communications paper. The findings may inform the development of suitable policies and response strategies to early eastern Pacific temperature changes.

Natural climate variability in the Pacific is largely governed by the El Niño–Southern Oscillation (ENSO), a coupling between the atmosphere and ocean, which has important and far-reaching implications for the climate and societies worldwide. ENSO alternates between a warm phase, termed El Niño, and a cold phase, called La Niña. Previous research has shown that ENSO events may have distinct characteristics depending on where the warm or cold temperatures are located, either in the equatorial eastern or central Pacific. However, when and where increased variability in ENSO changes is projected to occur, and the influence of anthropogenic climate change on these changes, remains unclear.

Tao Geng, Wenju Cai and colleagues analysed about 70 years of ENSO data from 1950 onwards and used some of the newest climate models to estimate when increased ENSO variability will be detectable in the eastern or central Pacific. They found that climate change associated temperature changes will likely be detectable around 2030 in the eastern Pacific, four decades earlier than previously expected. Additionally, the signal is projected to emerge earlier in the eastern than in the central Pacific, driven by the faster warming of this region and therefore a larger increase in rainfall. ENSO-related mitigation and adaption efforts, therefore, must consider the diversity in the response of each ENSO regime to greenhouse warming, they conclude.