新しいコンピューターモデルシミュレーションにより、人為的な強制が継続した場合の気候変動の広範な変化を特定
– New computer model simulations identify widespread changes in climate variability under sustained anthropogenic forcing –
気候変動における人為的変化の偏在性
Ubiquity of human-induced changes in climate variability
Keith B. Rodgers1,2, Sun-Seon Lee1,2, Nan Rosenbloom3, Axel Timmermann1,2, Gokhan Danabasoglu3, Clara Deser3, Jim Edwards3, Ji-Eun Kim1,2, Isla R. Simpson3, Karl Stein1,2, Malte F. Stuecker4, Ryohei Yamaguchi1,2, Tamás Bódai1,2, Eui-Seok Chung5, Lei Huang1,2, Who M. Kim3, Jean-François Lamarque3, Danica L. Lombardozzi3, William R. Wieder3,6, and Stephen G. Yeager3
1Center for Climate Physics, Institute for Basic Science, Busan, South Korea
2Pusan National University, Busan, South Korea
3National Center for Atmospheric Research, Boulder, CO, USA
4Department of Oceanography and International Pacific Research Center, School of Ocean and Earth Science and Technology, University of Hawai`i at Mānoa, Honolulu, HI, USA
5Korea Polar Research Institute, Incheon, South Korea
6Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO, USA
Correspondence: Keith B. Rodgers (krodgers@pusan.ac.kr) and Axel Timmermann (axel@ibsclimate.org)
Received: 25 Jun 2021 – Discussion started: 06 Jul 2021 – Revised: 05 Oct 2021 – Accepted: 09 Oct 2021 – Published: 09 Dec 2021
Abstract
While climate change mitigation targets necessarily concern maximum mean state changes, understanding impacts and developing adaptation strategies will be largely contingent on how climate variability responds to increasing anthropogenic perturbations. Thus far Earth system modeling efforts have primarily focused on projected mean state changes and the sensitivity of specific modes of climate variability, such as the El Niño–Southern Oscillation. However, our knowledge of forced changes in the overall spectrum of climate variability and higher-order statistics is relatively limited. Here we present a new 100-member large ensemble of climate change projections conducted with the Community Earth System Model version 2 over 1850–2100 to examine the sensitivity of internal climate fluctuations to greenhouse warming. Our unprecedented simulations reveal that changes in variability, considered broadly in terms of probability distribution, amplitude, frequency, phasing, and patterns, are ubiquitous and span a wide range of physical and ecosystem variables across many spatial and temporal scales. Greenhouse warming in the model alters variance spectra of Earth system variables that are characterized by non-Gaussian probability distributions, such as rainfall, primary production, or fire occurrence. Our modeling results have important implications for climate adaptation efforts, resource management, seasonal predictions, and assessing potential stressors for terrestrial and marine ecosystems.
