Increased outburst flood hazard from Lake Palcacocha due to human-induced glacier retreat
Increased outburst flood hazard from Lake Palcacocha due to human-induced glacier retreat
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DOI：
10.1038/s41561-021-00686-4
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发表时间：
2021-02-01
影响因子：
18.3
通讯作者：
Allen, M. R.
中科院分区：
文献类型：
--
作者：
Stuart-Smith, R. F.;Roe, G. H.;Allen, M. R.
根据观测和数值模型的分析，人为因素导致的气候变暖导致帕尔卡拉朱冰川的消退以及与之相关的冰川湖暴发洪水风险的增加。一场来自帕尔卡科察湖(秘鲁科迪勒拉·布兰卡)的潜在冰川湖暴发洪水威胁着拥有12万人口的城市瓦拉兹。1941年，一场突如其来的洪水摧毁了该市三分之一的地区，造成至少1800人死亡。自前工业时代以来，由于帕尔卡拉朱冰川的消退，帕尔卡科察湖已经扩张。在这里，我们使用观测和数值模型来评估人为因素对冰川退缩和冰川湖暴发洪水风险的影响。我们发现，人类导致的变暖幅度相当于该地区自1880年以来观测到的1摄氏度变暖的85%到105%(5-95%的可信区间)。我们的结论是，帕尔卡拉朱冰川退缩到今天的可能性几乎是肯定的(99%)，不能仅用自然变化来解释，而且到1941年的退缩代表了人为温室气体排放的早期影响。我们的中心估计是，总体退缩完全可归因于观测到的温度趋势，由此导致的湖泊和山谷几何形状的变化大大增加了洪水暴发的风险。
Human-induced warming is responsible for the retreat of Palcaraju glacier and the associated increase in glacial lake outburst flood hazard, according to an analysis of observations and numerical models.A potential glacial lake outburst flood from Lake Palcacocha (Cordillera Blanca, Peru) threatens Huaraz, a city of 120,000 people. In 1941, an outburst flood destroyed one-third of the city and caused at least 1,800 fatalities. Since pre-industrial times, Lake Palcacocha has expanded due to the retreat of Palcaraju glacier. Here we used observations and numerical models to evaluate the anthropogenic contribution to the glacier's retreat and glacial lake outburst flood hazard. We found that the magnitude of human-induced warming equals between 85 and 105% (5-95% confidence interval) of the observed 1 degrees C warming since 1880 in this region. We conclude that it is virtually certain (>99% probability) that the retreat of Palcaraju glacier to the present day cannot be explained by natural variability alone, and that the retreat by 1941 represented an early impact of anthropogenic greenhouse gas emissions. Our central estimate is that the overall retreat is entirely attributable to the observed temperature trend, and that the resulting change in the geometry of the lake and valley has substantially increased the outburst flood hazard.