The warming climate can considerably affect socioeconomic activities and environmental health conditions in Canada. Climate models play a key role in evaluating the impact of climate change and developing adaption and mitigation strategies corresponding to Canadian regions. This study compares the behavior of climate models participating in the Climate Model Intercomparison Project Phase 6 (CMIP6) with their CMIP5 predecessors in representing a set of climate indices relevant to Canada’s agricultural productivity, infrastructure resilience, and environmental health. Our results show that although CMIP5 and CMIP6 multi‐model ensemble mean values for the considered indices are almost similar, the behavior of individual CMIP5 and CMIP6 models or even the model pairs of the same modeling center can be different across Canada. Moreover, the CMIP6 models do not necessarily outperform CMIP5 in comparison to NOAA and NCEP reanalysis datasets in simulating the annual mean and coefficient of variation values for the indices during the historical period. The comparisons between models’ simulations also reveal that the envelope of estimated values based on individual CMIP6 models does not cover or overlap with their CMIP5 counterparts or even with other CMIP6 models. Therefore, the CMIP6 models with higher number of simulations do not necessarily provide a larger range of projections over Canadian regions. The divergence between CMIP5 and CMIP6 models’ behavior is more obvious under the 8.5 W/m² forcing in the long‐term horizon. Overall, the estimated sign, magnitude, and spatial pattern of changes in the climate indices depend on the considered climate model and forcing scenario.

中文翻译：

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CMIP5和CMIP6模型之间的比较：模拟影响加拿大粮食安全，基础设施弹性和人类健康的气候指标

气候变暖会严重影响加拿大的社会经济活动和环境健康状况。气候模型在评估气候变化的影响以及制定与加拿大地区相对应的适应和减缓战略方面发挥着关键作用。这项研究比较了参与气候模型比对项目第6阶段（CMIP6）的气候模型及其CMIP5的前者在代表与加拿大农业生产率，基础设施弹性和环境健康相关的一组气候指数方面的行为。我们的结果表明，尽管所考虑指标的CMIP5和CMIP6多模型总体均值几乎相似，但在整个加拿大，单个CMIP5和CMIP6模型甚至同一建模中心的模型对的行为都可能不同。而且，相较于NOAA和NCEP再分析数据集，CMIP6模型在模拟历史时期的指标的年均值和变异系数值时，不一定优于CMIP5。模型仿真之间的比较还显示，基于单个CMIP6模型的估计值的包络不覆盖或与其CMIP5对应物甚至其他CMIP6模型重叠。因此，具有较多模拟量的CMIP6模型不一定在加拿大地区提供较大范围的投影。在8.5 W / m下，CMIP5和CMIP6模型的行为差异更加明显 模型仿真之间的比较还显示，基于单个CMIP6模型的估计值的包络不覆盖或与其CMIP5对应物甚至其他CMIP6模型重叠。因此，具有较多模拟量的CMIP6模型不一定在加拿大地区提供较大范围的投影。在8.5 W / m下，CMIP5和CMIP6模型的行为差异更加明显 模型仿真之间的比较还显示，基于单个CMIP6模型的估计值的包络不覆盖或与其CMIP5对应物甚至其他CMIP6模型重叠。因此，具有较多模拟量的CMIP6模型不一定在加拿大地区提供较大范围的投影。在8.5 W / m下，CMIP5和CMIP6模型的行为差异更加明显²从长远的角度来看。总体而言，气候指数变化的估计符号，幅度和空间格局取决于所考虑的气候模型和强迫情景。