[A-CG38] Climate Variability and Predictability on Subseasonal to Centennial Timescales

[ACG38-10] Global and Regional Drivers for Exceptional Climate Extremes in 2023-2024: Beyond the New Normal

*見延 庄士郎¹、Behrens Erik²、Findell Kirsten³、Loeb Norman⁴、Meyssignac Benoit⁶、Sutton Rowan⁵ (1.北海道大学大学院理学研究院、2.The National Institute of Water and Atmospheric Research、3.Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration、4.NASA Langley Research Center、5.University of Reading and National Centre for Atmospheric Science、6.Université de Toulouse, LEGOS (CNES/CNRS/IRD/UT3))

キーワード：地球温暖化の加速、地球の熱エネルギーのバランスの崩れ、海洋熱貯熱量、エルニーニョ

Climate records have been broken with alarming regularity in recent years, but the events of 2023-24 were exceptional even when accounting for recent climatic trends. Here we quantify these events across multiple variables and show how excess energy accumulation in the Earth system drove the exceptional conditions. Key factors were the positive decadal trend in Earth’s Energy Imbalance (EEI), persistent La Niña conditions beginning in 2020, and the switch to El Niño in 2023. Between 2022 and 2023, the heating from EEI was over 75% larger than during the onset of similar recent El Niño events. We show further how regional processes shaped distinct patterns of record-breaking sea surface temperatures in individual ocean basins. If the recent trend in EEI is maintained, we argue that natural fluctuations such as ENSO cycles will increasingly lead to amplified, record-breaking impacts, with 2023-2024 serving as a glimpse of future climate extremes.