Scholarlink

<p>Over the past century, Arctic surface temperature has exhibited three distinct phases: early 20th-century warming (1920–1940&#xa0;s), mid-century cooling (1940–1970&#xa0;s), and recent accelerated warming (1970–2020&#xa0;s). Disentangling the relative roles of external forcings and internal variability across these phases remains a key challenge. Here, we apply a regularized optimal fingerprinting method to simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to quantify the evolving contributions of greenhouse gases, anthropogenic aerosols, and natural forcings to Arctic surface temperature changes over 1920–2020. We find a clear contrast between the two warming periods. The early 20th-century warming (i.e., 1920–1939) is only partly explained by external forcings, with a substantial contribution from internal variability. In contrast, the recent accelerated warming (i.e., 1971–2020) is almost entirely attributable to external forcings, dominated by greenhouse gas emissions. Importantly, we identify a systematic underestimation of aerosol-induced cooling in CMIP6 models during the mid-century period (i.e., 1940–1970). This bias suggests that future Arctic warming associated with declining aerosol emissions may be stronger than currently projected. These results highlight the increasingly dominant anthropogenic influence on Arctic climate and provide new constraints on the relative roles of external forcing and internal variability in shaping Arctic temperature evolution.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Evolving drivers of 20th-century arctic climate: a detection and attribution analysis with CMIP6 models

  • 期刊论文

  • 发表日期：

    2026年6月17日

查看全文
  • Di Cai,
  • Xianyao Chen,
  • Monica Ionita

摘要

Over the past century, Arctic surface temperature has exhibited three distinct phases: early 20th-century warming (1920–1940 s), mid-century cooling (1940–1970 s), and recent accelerated warming (1970–2020 s). Disentangling the relative roles of external forcings and internal variability across these phases remains a key challenge. Here, we apply a regularized optimal fingerprinting method to simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to quantify the evolving contributions of greenhouse gases, anthropogenic aerosols, and natural forcings to Arctic surface temperature changes over 1920–2020. We find a clear contrast between the two warming periods. The early 20th-century warming (i.e., 1920–1939) is only partly explained by external forcings, with a substantial contribution from internal variability. In contrast, the recent accelerated warming (i.e., 1971–2020) is almost entirely attributable to external forcings, dominated by greenhouse gas emissions. Importantly, we identify a systematic underestimation of aerosol-induced cooling in CMIP6 models during the mid-century period (i.e., 1940–1970). This bias suggests that future Arctic warming associated with declining aerosol emissions may be stronger than currently projected. These results highlight the increasingly dominant anthropogenic influence on Arctic climate and provide new constraints on the relative roles of external forcing and internal variability in shaping Arctic temperature evolution.