There has been increasing interest in understanding climate change impacts on crop yield stability, including interannual yield variability and lower yield extremes, in addition to mean yield. In this study, we evaluated these impacts on wheat yield and investigated the contribution of changes in climate mean and variability, and their interaction, on the North China Plain (NCP). Wheat yield simulation experiments with control groups were conducted using the Crop Environment Resource Synthesis (CERES) model, with multiple general circulation model ensembles under two representative concentration pathways (RCPs), namely 4.5 and 8.5. Climate change was projected to reduce mean yield by 15 and 17%, increase yield interannual variability by 5 and 11%, and reduce 10‐year return period lower yield extremes by 31 and 34% under RCPs 4.5 and 8.5, respectively. When analysed, changes in climate mean proved the main cause for changes in mean yield (62–71%), followed by the interactive changes in climate mean and variability (26–33%). As for the impact on yield variability, the interaction of the changes in climate mean and variability proved the main cause (48–54%), followed by changes in climate mean (33–41%). Surprisingly, climate change in variability contributed the least in both cases. Our results pertaining to the decrease in both availability and stability of wheat yield on the NCP presents a greater challenge for building a resilient food system for local areas than before. They also highlighted the importance of separating the impacts of changes in climate mean and variability on crop yield stability in a holistic framework, with particular attention paid to the tangible and interactive effects.

中文翻译：

---

华北平原小麦单产下降：气候变化对均值和变异性的相对贡献

人们越来越了解气候变化对农作物单产稳定性的影响，除了平均单产外，还包括年际单产变化和极端单产降低。在这项研究中，我们评估了这些因素对小麦单产的影响，并研究了气候平均值和变异性变化及其对华北平原（NCP）的贡献。使用作物环境资源综合模型（CERES）对小麦进行了模拟对照组的实验，在两个代表性的浓度途径（RCPs），即4.5和8.5下，多个普通循环模型集合在一起。根据RCP 4.5和8.5，预计气候变化将使平均单产降低15％和17％，使年际变异率提高5％和11％，并减少10年回归期，将极端极端情况下的单产极端值降低31％和34％，分别。经分析，气候平均值的变化被证明是造成平均产量变化的主要原因（62-71％），其次是气候平均值和变异性的交互变化（26-33％）。至于对产量变异性的影响，气候平均值和变异性的相互作用被证明是主要原因（48–54％），其次是气候平均值的改变（33–41％）。出乎意料的是，在两种情况下，气候变化对变化的影响最小。与NCP上小麦产量的可用性和稳定性均下降有关的我们的研究结果，对建立本地有弹性的粮食系统提出了更大的挑战。他们还强调了在一个整体框架内分离气候平均值和变异性对作物产量稳定性的影响的重要性，