近日，美国达特茅斯学院Gottlieb, Alexander R.的一项最新研究提出了人类活动影响北半球雪量减少的证据。2024年1月10日出版的《自然》发表了这项成果。

研究人员称，在1981-2020年期间，人为影响主导的变暖已经引起北半球规模3月份的积雪量的减少。研究利用积雪重建的集合，确定了北半球169个主要河流流域中82个流域的强降雪趋势，其中的31个可以被归因于人类的影响。最重要的是，研究人员展示了积雪的概化和高度非线性的温度敏感性，其中当冬季气候温度超过零下8摄氏度时，积雪对1摄氏度的变化变得稍微更加敏感。

这种非线性解释了迄今为止没有大范围降雪的原因，并预示着在大多数人口稠密的盆地中，会出现更大幅度的下降和水安全风险。总之，研究结果强调，人为造成的雪量减少及其对水资源的影响是可归因的（即使在个别雪制品中没有明确的检测），并且将随着近期变暖而加速和均匀化，在没有实质性气候缓解的情况下对水资源构成风险。

据介绍，记录积雪损失的速度、幅度和原因，对于衡量气候变化的速度和管理积雪减少的不同水安全风险至关重要。然而，到目前为止，雪量观测的不确定性使人为影响降雪损失的探测和归因变得难以实现，也影响了社会的准备工作。

附：英文原文

Title: Evidence of human influence on Northern Hemisphere snow loss

Author: Gottlieb, Alexander R., Mankin, Justin S.

Issue&Volume: 2024-01-10

Abstract: Documenting the rate, magnitude and causes of snow loss is essential to benchmark the pace of climate change and to manage the differential water security risks of snowpack declines. So far, however, observational uncertainties in snow mass have made the detection and attribution of human-forced snow losses elusive, undermining societal preparedness. Here we show that human-caused warming has caused declines in Northern Hemisphere-scale March snowpack over the 1981–2020 period. Using an ensemble of snowpack reconstructions, we identify robust snow trends in 82 out of 169 major Northern Hemisphere river basins, 31 of which we can confidently attribute to human influence. Most crucially, we show a generalizable and highly nonlinear temperature sensitivity of snowpack, in which snow becomes marginally more sensitive to one degree Celsius of warming as climatological winter temperatures exceed minus eight degrees Celsius. Such nonlinearity explains the lack of widespread snow loss so far and augurs much sharper declines and water security risks in the most populous basins. Together, our results emphasize that human-forced snow losses and their water consequences are attributable—even absent their clear detection in individual snow products—and will accelerate and homogenize with near-term warming, posing risks to water resources in the absence of substantial climate mitigation.

DOI: 10.1038/s41586-023-06794-y

Source: https://www.nature.com/articles/s41586-023-06794-y