This paper reviews the sources of uncertainty in physical climate impact assessments. It draws on examples from related fields such as climate modelling and numerical weather prediction in discussing how to interpret the results of multi-model ensembles and the role of model evaluation. Using large-scale, multi-model simulations of hydrological extremes as an example, we demonstrate how large uncertainty at the local scale does not preclude more robust conclusions at the global scale. Finally, some recommendations are made: climate impact studies should be clear about the questions they want to address, transparent about the uncertainties involved, and honest about the assumptions being made.

中文翻译：

---

应对水资源物理气候影响预测的不确定性

本文回顾了物理气候影响评估中不确定性的来源。它借鉴了气候建模和数值天气预报等相关领域的例子，讨论了如何解释多模式集合的结果以及模式评估的作用。以水文极端事件的大规模、多模型模拟为例，我们证明了局部尺度的巨大不确定性并不能排除全球尺度上更可靠的结论。最后，提出了一些建议：气候影响研究应该明确他们想要解决的问题，透明化所涉及的不确定性，并诚实地做出假设。