The Effect of Global Warming on Future Water Availability: CMIP5 Synthesis
The Effect of Global Warming on Future Water Availability: CMIP5 Synthesis
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DOI：
10.1029/2018wr022792
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发表时间：
2018-10
影响因子：
5.4
通讯作者：
C. Ferguson;M. Pan;T. Oki
中科院分区：
文献类型：
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作者：
C. Ferguson;M. Pan;T. Oki
全球水循环时空动态的变化将构成变暖世界中社会经济环境福祉的一些最大挑战。大型多模型、多情景比对，例如耦合模型比对项目第五阶段（CMIP5）实验，支持我们对预计气候变化及其相关不确定性的最佳估计。不断重新评估这些信息的合成和传达方式以及何时变得可操作非常重要。在这项研究中，我们展示了一个系统和整体的框架，用于综合大流域规模（水资源管理和监测的规模）的可用水量的多模型集合预测。根据 CMIP5 历史（1976-2005）和代表性浓度路径 8.5（2070-2099）情景多模型集合输出计算得出，我们确定了年度和月度平均可用水量、其年际变化及其相对季节性的统计显着变化。可用水量分别通过气象学家（降水）、水文学家（径流）和农业学家（降水减去蒸散量）的视角来讨论。我们通过将纯大气模型（大气模型比对项目）输出与观测最佳估计进行比较来说明 CMIP5 模型代表性的局限性。我们发现，CMIP5 碳循环地球系统模型预测的由变暖引起的可用水量变化比传统大气环流模型预测的变化相对较小。正如我们所表明的，了解预测变化的季节性以及施加这些变化的有偏差的模型背景气候学对于确保正确解释和赋予信心至关重要。
Changes in the spatiotemporal dynamics of the global water cycle will constitute some of the greatest challenges to socioeconomic‐environmental well‐being in a warming world. Large multimodel, multiscenario intercomparisons such as the Coupled Model Intercomparison Project Phase 5 (CMIP5) experiment support our best estimates of projected climate change and associated uncertainty thereof. It is important to continually reevaluate how this information is synthesized and communicated and at what point it becomes actionable. In this study, we demonstrate a systematic and holistic framework for synthesizing multimodel ensemble projections of water availability at large river basin scale—the scale at which water resources are both managed and monitored. We identify statistically significant shifts in mean water availability at annual and monthly scales, its interannual variations, and its relative seasonality, as computed from CMIP5 historical (1976–2005) and Representative Concentration Pathway 8.5 (2070–2099) scenario multimodel ensemble output. Water availability is addressed separately through the lens of meteorologists (precipitation), hydrologists (runoff), and agriculturalists (precipitation minus evapotranspiration). We illustrate limitations in CMIP5 model representativeness through comparisons of atmosphere‐only model (Atmospheric Model Intercomparison Project) output against observational best estimates. And we find that warming‐induced shifts in water availability projected by CMIP5 carbon‐cycling Earth system models are comparatively less substantial than those projected by traditional general circulation models. As we show, knowing the seasonality of both projected changes and of the biased model background climatology onto which they are imposed is paramount to ensuring proper interpretation and ascribing confidence.