Amplified seasonality in western Europe in a warmer world

• Published in: Science Advances
• Main Authors: de Winter, Niels J., Tindall, Julia, Johnson, Andrew L. A., Goudsmit-Harzevoort, Barbara, Wichern, Nina, Kaskes, Pim, Claeys, Philippe, Huygen, Fynn, van Leeuwen, Sonja, Metcalfe, Brett, Bakker, Pepijn, Goolaerts, Stijn, Wesselingh, Frank, Ziegler, Martin
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 2024
• Subjects: Arctic; Global warming
• Online Access: http://dx.doi.org/10.1126/sciadv.adl6717; https://www.science.org/doi/pdf/10.1126/sciadv.adl6717

Documenting the seasonal temperature cycle constitutes an essential step toward mitigating risks associated with extreme weather events in a future warmer world. The mid-Piacenzian Warm Period (mPWP), 3.3 to 3.0 million years ago, featured global temperatures approximately 3°C above preindustrial levels. It represents an ideal period for directed paleoclimate reconstructions equivalent to model projections for 2100 under moderate Shared Socioeconomic Pathway SSP2-4.5. Here, seasonal clumped isotope analyses of fossil mollusk shells from the North Sea are presented to test Pliocene Model Intercomparison Project 2 outcomes. Joint data and model evidence reveals enhanced summer warming (+4.3° ± 1.0°C) compared to winter (+2.5° ± 1.5°C) during the mPWP, equivalent to SSP2-4.5 outcomes for future climate. We show that Arctic amplification of global warming weakens mid-latitude summer circulation while intensifying seasonal contrast in temperature and precipitation, leading to an increased risk of summer heat waves and other extreme weather events in Europe’s future.