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

本研究旨在全面评估人类对工业时代全球山地冰川退缩的贡献。这一结果将为政府间气候变化专门委员会（IPCC）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最明确证据之一，但将其归因于原因的正式科学声明仍然令人惊讶地薄弱。不愿作出更强有力的声明的原因是：i)冰川自然变率的不确定性；ii)前一个小冰期冰川的潜在退缩；第三，全球范围内缺乏专门的针对性研究。这项研究将把以前开发的归因方法应用于最新的全球冰川几何数据集，并结合对过去一千年气候的重建和数值模拟。研究结果将立即对从事高山地表过程和危害研究的研究人员、生态学家以及所有研究和解释冰周环境的人产生影响；包括研究社会影响的社会学家、地理学家和经济学家。目前冰川退缩的不明确归属也在寻求建立气候正义法律原则的判例诉讼中发挥了作用，而这项工作对此有所贡献。IPCC需要新的研究来更新其评估，从而巩固（或反驳）先前的分析，建议：i)使用来自约20个全球气候模式的多世纪整体模拟，将模拟冰川适当地初始化为工业化前的气候，并提供有和没有人为强迫的模拟对；ii)使用从开放全球冰川模型获得的真实冰川集水区几何形状和流线，最初使用约50个全球分散的冰川，随后扩展到更大的网络；iii)采用基于过程的冰川流线动力学数值模型。这将把理论和综合分析与实际景观和冰流动力学结合起来，并结合全面估计的自然气候变化。这项研究将特别关注北方高纬度地区冰川的人为归因，因为那里的自然气候变化很大；低频变异性强；后来出现的人为气候变化的信号；对太阳和火山强迫的强烈反应；在海洋环境中，冬季物质平衡的变化很大。该奖项是由美国国家科学基金会的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的，这些项目跨越了地球科学部、大气和地球空间科学部和极地项目。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.