[A-CG43] 北極域の科学

[ACG43-P01] Enhanced Arctic warming amplification revealed in a low-emission scenario

*小野 純¹、渡部 雅浩²、小室 芳樹¹、建部 洋晶¹、阿部 学¹ (1.国立研究開発法人　海洋研究開発機構、2.東京大学　大気海洋研究所)

The Arctic has warmed faster than the global mean in past decades. Future climate change projections also suggest the warming in the Arctic will be greater than in other latitudes, called the Arctic warming amplification. Here, using 50-member historical and future scenario simulations by a single climate model, we show that the Arctic warming is enhanced in a low-emission scenario after the mid-2040s. This is because Arctic warming is not weakened than global warming via ice-albedo feedback while sea ice exists, unlike in a high-emission scenario in which summer sea ice melts away by about 2050. Multi-model analyses show that the strength of Arctic amplification in the low-emission scenario is highly correlated with the amount of sea-ice reduction, whereas this relationship weakens in the high-emission scenario. Our results indicate that climate change mitigation may have a side effect because the Arctic warming persists even if the global warming is stabilized.