Webb Hailey, Fuchs Matthias, Abbott Benjamin W, Douglas Thomas A, Elder Clayton D, Ernakovich Jessica Gilman, Euskirchen Eugenie S, Göckede Mathias, Grosse Guido, Hugelius Gustaf, Jones Miriam C, Koven Charles, Kropp Heather, Lathrop Emma, Li WenWen, Loranty Michael M, Natali Susan M, Olefeldt David, Schädel Christina, Schuur Edward A G, Sonnentag Oliver, Strauss Jens, Virkkala Anna-Maria, Turetsky Merritt R
Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO USA.
Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO USA.
Curr Clim Change Rep. 2025;11(1):7. doi: 10.1007/s40641-025-00204-3. Epub 2025 Jul 24.
We review how 'abrupt thaw' has been used in published studies, compare these definitions to abrupt processes in other Earth science disciplines, and provide a definitive framework for how abrupt thaw should be used in the context of permafrost science.
We address several aspects of permafrost systems necessary for abrupt thaw to occur and propose a framework for classifying permafrost processes as abrupt thaw in the future. Based on a literature review and our collective expertise, we propose that abrupt thaw refers to thaw processes that lead to a substantial persistent environmental change within a few decades. Abrupt thaw typically occurs in ice-rich permafrost but may be initiated in ice-poor permafrost by external factors such as hydrologic change (i.e., increased streamflow, soil moisture fluctuations, altered groundwater recharge) or wildfire.
Permafrost thaw alters greenhouse gas emissions, soil and vegetation properties, and hydrologic flow, threatening infrastructure and the cultures and livelihoods of northern communities. The term 'abrupt thaw' has emerged in scientific discourse over the past two decades to differentiate processes that rapidly impact large depths of permafrost, such as thermokarst, from more gradual, top-down thaw processes that impact centimeters of near-surface permafrost over years to decades. However, there has been no formal definition for abrupt thaw and its use in the scientific literature has varied considerably. Our standardized definition of abrupt thaw offers a path forward to better understand drivers and patterns of abrupt thaw and its consequences for global greenhouse gas budgets, impacts to infrastructure and land-use, and Arctic policy- and decision-making.
The online version contains supplementary material available at 10.1007/s40641-025-00204-3.
我们回顾已发表研究中“突然解冻”的使用情况，将这些定义与其他地球科学学科中的突变过程进行比较，并为在多年冻土科学背景下如何使用突然解冻提供一个明确的框架。
我们探讨了突然解冻发生所需的多年冻土系统的几个方面，并提出了一个未来将多年冻土过程分类为突然解冻的框架。基于文献综述和我们的集体专业知识，我们提出突然解冻是指在几十年内导致持续重大环境变化的解冻过程。突然解冻通常发生在富含冰的多年冻土中，但也可能由水文变化（即流量增加、土壤湿度波动、地下水补给改变）或野火等外部因素在贫冰多年冻土中引发。
多年冻土解冻会改变温室气体排放、土壤和植被特性以及水文流动，威胁基础设施以及北方社区的文化和生计。在过去二十年的科学论述中出现了“突然解冻”一词，以区分迅速影响多年冻土深层的过程，如热喀斯特，与多年到几十年间影响近地表几厘米多年冻土的更渐进的自上而下的解冻过程。然而，对于突然解冻并没有正式的定义，其在科学文献中的使用也有很大差异。我们对突然解冻的标准化定义为更好地理解突然解冻的驱动因素和模式及其对全球温室气体预算、对基础设施和土地利用的影响以及北极政策和决策的后果提供了一条前进的道路。
在线版本包含可在10.1007/s40641-025-00204-3获取的补充材料。
