Attribution of industrial-era glacier retreat, globally and in the high northern latitudes.

这项研究旨在全面评估人类对世界各地工业时代山脉冰川消退的贡献。这一结果将为政府间气候变化专门委员会(气专委)未来的评估奠定更坚实的基础。尽管冰川退缩被广泛吹捧为人为气候变化影响的一些最明确的证据，但归因于这一原因的正式科学声明仍然令人惊讶地薄弱。对做出更有力的声明犹豫不决的原因是：i)冰川自然变异性的不确定性；ii)冰川可能从之前的小冰期退缩；iii)缺乏在全球范围内有针对性的研究。这项研究将把以前开发的归属方法应用于新获得的冰川几何全球数据集，并结合对过去千年气候的重建和数值模拟。研究结果将立即对研究高山地表过程和灾害的研究人员、生态学家以及所有研究和解释冰缘环境的人产生影响，包括社会学家、地理学家和研究社会影响的经济学家。目前不清楚的冰川退缩归属也在寻求建立气候正义法律原则的开创先例的诉讼中发挥作用，这项工作做出了贡献。政府间气候变化专门委员会需要新的研究来更新其评估，因此为了巩固先前的分析(或反驳它们)，建议：i)使用来自约20个全球气候模型的多世纪集合模拟，适当地将模拟的冰川初始化为工业化前的气候，并提供有人为强迫和无人为强迫的模拟对；Ii)使用从开放式全球冰川模型获得的真实冰川集水区几何形状和流线，最初有大约50个分散在全球各地的冰川，随后扩展到一个更大的网络；以及iii)使用基于过程的流线冰川动力学数值模型。这将对真实的地形和冰流动力学进行理论和综合分析，并结合全面估计的自然气候变异性。研究将继续侧重于北部高纬度冰川的人为归属问题，这些冰川经历了较大的自然气候变率；较强的低频变率；较晚出现的人为气候变化信号；对太阳和火山强迫的强烈反应；以及在海洋环境中，冬季物质平衡的较大变率。该奖项由地貌学和土地利用动力学、北极自然科学、气候和大规模动力学项目共同资助，这些项目横跨地球科学部、大气和地球空间科学部以及NSF的极地项目。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This research aims to provide a comprehensive evaluation of the human contribution to the industrial-era retreat of mountain glaciers around the world. The result will be a stronger foundation for future assessments by the Intergovernmental Panel on Climate Change (IPCC). Although glacier retreat is widely touted as some of the clearest evidence of the impacts of anthropogenic climate change, formal scientific statements attributing the cause remain surprisingly weak. Hesitancy to make stronger statements stems from: i) uncertainty about the natural variability of glaciers; ii) the potential retreat of glaciers from a preceding Little Ice Age; and iii) a dearth of specifically targeted research on a global scale. The research will apply a previously developed attribution methodology to newly available global datasets of glacier geometry, combined with reconstructions and numerical simulations of the climate of the past millennium. The results will be immediately impactful for researchers working on high-mountain surface processes and hazards, ecologists, and all those who study and interpret periglacial environments; including sociologists, geographers, and economists who study societal impacts. The current unclear attribution of glacier retreat is also playing a role in precedent-setting lawsuits seeking to establish the legal principles of climate justice, to which the work contributes.The IPCC needs new research in order to update its assessments, and so to cement prior analyses (or disprove them), it is proposed to: i) use multi-century ensemble simulations from ~20 global climate models to properly initialize simulated glaciers to a pre-industrial climate, and to provide pairs of simulations with-and-without anthropogenic forcing; ii) use real glacier-catchment geometries and flowlines obtained from the Open Global Glacier Model initially with ~50 globally dispersed glaciers, with subsequent expansion to a larger network; and iii) use process-based numerical models of flowline glacier dynamics. This will put theoretical and synthetic analyses onto real landscapes and ice-flow dynamics, in combination with a full range of estimated natural climate variability. The research will maintain a particular focus on anthropogenic attribution for glaciers in the northern high latitudes, which experience large natural climate variability; strong low-frequency variability; a later emergence of the signal of anthropogenic climate change; a strong response to solar and volcanic forcing; and in maritime settings, large variability in wintertime mass balance. This award is co-funded by the Geomorphology and Land-use Dynamics, Arctic Natural Sciences, and Climate and Large-scale Dynamics programs, which cross the Division of Earth Sciences, Division of Atmospheric and Geospace Sciences, and Polar Programs at the NSF.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.