High potential for loss of permafrost landforms in a changing climate
High potential for loss of permafrost landforms in a changing climate
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DOI：
10.1088/1748-9326/abafd5
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发表时间：
2020-10
影响因子：
6.7
通讯作者：
O. Karjalainen;M. Luoto;J. Aalto;B. Etzelmüller;G. Grosse;B. Jones;K. S. Lilleøren;J. Hjort
中科院分区：
文献类型：
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作者：
O. Karjalainen;M. Luoto;J. Aalto;B. Etzelmüller;G. Grosse;B. Jones;K. S. Lilleøren;J. Hjort
北极土壤中冰的存在对冻土水文和生态产生重大影响，并对地貌地貌发育有重要影响。由于大多数地面冰积累在近地表的永久冻土中，因此对大气条件的变化很敏感。典型的和区域性广泛分布的永久冻土地貌，如冰丘、冰楔多边形和岩石冰川与地面冰密切相关。然而，在持续的气候变化下，适合保护与富含冰的永久冻土有关的地貌的环境空间可能正在迅速消失。我们部署了一个统计集成的方法来模拟，第一次，当前和潜在的未来环境条件的三个典型的永久冻土地貌，冰丘，冰楔多边形和岩石冰川横跨北方半球。我们表明，到本世纪中叶，地貌预计将失去超过五分之一的适宜环境下的温和气候情景（RCP 4.5）和平均约三分之一的非常高的基线排放情景（RCP 8.5），即使预计新的合适的发生区域被认为。到2061-2080年，平均超过50%的近期适宜条件可能丧失（RCP 8.5）。在冰丘和冰楔多边形的情况下，地理变化主要是由于在解冻季节降水和气温的变化。岩石冰川在适当的条件下表现出受地形和土壤性质强烈制约的气温引起的区域变化。预测的损失可能会对北极水文、地质和生物多样性产生重要影响，并通过受永久冻土地貌影响的地球化学循环的变化对全球气候系统产生重要影响。此外，我们的预测提供了对各种地面冰类型的环极分布的见解，并帮助在未绘制地图的地区的永久冻土地貌的库存。
The presence of ground ice in Arctic soils exerts a major effect on permafrost hydrology and ecology, and factors prominently into geomorphic landform development. As most ground ice has accumulated in near-surface permafrost, it is sensitive to variations in atmospheric conditions. Typical and regionally widespread permafrost landforms such as pingos, ice-wedge polygons, and rock glaciers are closely tied to ground ice. However, under ongoing climate change, suitable environmental spaces for preserving landforms associated with ice-rich permafrost may be rapidly disappearing. We deploy a statistical ensemble approach to model, for the first time, the current and potential future environmental conditions of three typical permafrost landforms, pingos, ice-wedge polygons and rock glaciers across the Northern Hemisphere. We show that by midcentury, the landforms are projected to lose more than one-fifth of their suitable environments under a moderate climate scenario (RCP4.5) and on average around one-third under a very high baseline emission scenario (RCP8.5), even when projected new suitable areas for occurrence are considered. By 2061–2080, on average more than 50% of the recent suitable conditions can be lost (RCP8.5). In the case of pingos and ice-wedge polygons, geographical changes are mainly attributed to alterations in thawing-season precipitation and air temperatures. Rock glaciers show air temperature-induced regional changes in suitable conditions strongly constrained by topography and soil properties. The predicted losses could have important implications for Arctic hydrology, geo- and biodiversity, and to the global climate system through changes in biogeochemical cycles governed by the geomorphology of permafrost landscapes. Moreover, our projections provide insights into the circumpolar distribution of various ground ice types and help inventory permafrost landforms in unmapped regions.