2023 summer warmth unparalleled over the past 2,000 years

• 成果类型: Article
• 署名作者: Esper, Jan; Torbenson, Max; Buentgen, Ulf
• 署名单位: Johannes Gutenberg University of Mainz; Czech Academy of Sciences; Global Change Research Centre of the Czech Academy of Sciences; University of Cambridge; Masaryk University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-5918
• DOI: 10.1038/s41586-024-07512-y
• 发表日期: 2024-07-04
• 页码: 94-97
• 关键词: surface-temperature; mount-pinatubo; exposure

摘要

Including an exceptionally warm Northern Hemisphere summer(1,2), 2023 has been reported as the hottest year on record(3-5). However, contextualizing recent anthropogenic warming against past natural variability is challenging because the sparse meteorological records from the nineteenth century tend to overestimate temperatures(6). Here we combine observed and reconstructed June-August surface air temperatures to show that 2023 was the warmest Northern Hemisphere extra-tropical summer over the past 2,000 years exceeding the 95% confidence range of natural climate variability by more than 0.5 degrees C. Comparison of the 2023 June-August warming against the coldest reconstructed summer in CE 536 shows a maximum range of pre-Anthropocene-to-2023 temperatures of 3.93 degrees C. Although 2023 is consistent with a greenhouse-gases-induced warming trend(7) that is amplified by an unfolding El Nino event(8), this extreme emphasizes the urgency to implement international agreements for carbon emission reduction.