Interannual temperature variability plays a critical role in determining the frequency and intensity of extreme climate events. Understanding how this variability responds to different external forcings is essential for assessing future climate risks. However, the short length of instrumental records limits our knowledge of its behavior and mechanisms at long-term scales.
As past representative warm and cold periods respectively, the Last Interglacial (LIG, ~129–116 ka) and Last Glacial Maximum (LGM, ~23–19 ka) offer two ideal natural experiments for investigating how temperature variability responds to distinct forcings. However, changes in interannual temperature variability over China during these periods have not been systematically quantified, nor have the underlying mechanisms been compared across different climate backgrounds. In particular, it remains unclear whether the temperature variability responded uniformly across seasons and regions, and which energy balance components dominated the changes.
To address these questions, researchers from the Shanghai Regional Climate Center, China, and Institute of Atmospheric Physics, Chinese Academy of Sciences, China, quantified the changes in interannual temperature variability over China during the past warm period of the Last Interglacial and the cold period of the Last Glacial Maximum, as well as the associated mechanisms, using all available simulations performed by 12 state-of-the-art global climate models. The results have recently been published in Atmospheric and Oceanic Science Letters .
Using seven models chosen for their good performance, the study shows that the interannual temperature variability increased over China during both the LIG and LGM, with national average increases of 8% and 15%, respectively. Seasonally, the LIG exhibits a greater variability increase in summer than in winter, whereas the LGM shows a stronger winter than summer variability increase. These asymmetric seasonal patterns are primarily driven by different responses of atmospheric energy budget components to external forcings of LIG insolation changes and LGM reduced greenhouse gas concentrations, respectively, which are particularly pronounced in eastern China.
"These paleoclimate insights reveal that changes in interannual temperature variability and their driving mechanisms are closely linked to the background climate state with specific external forcings," explains the corresponding author, Associate Prof. Zhiping Tian. "Therefore, this study provides a critical long-term perspective for understanding future changes in extreme temperature events."
Atmospheric and Oceanic Science Letters
Increased interannual variability of temperature over China during the last interglacial and last glacial maximum: Magnitudes and asymmetric seasonal patterns
5-Mar-2026