Commentary: The impact of climate change on landslides in southeastern of high-latitude permafrost regions of China

Citation: Juanico DEO (2016) Commentary: The impact of climate change on landslides in southeastern of high-latitude permafrost regions of China. Front. Earth Sci. 4:11. Permafrost melting could trigger geomorphic change processes on the Earth's surface, such as landslides, ground subsidence, and erosion. Although permafrost accounts for a minute portion of the Earth's total water content, it occurs at substantial concentrations in high latitudes of the Northern Hemisphere. Permafrost also locks in high amounts of greenhouse gases, such as carbon dioxide and methane. Consequently, the accelerated thawing, associated with the rise in global temperatures, could release more greenhouse gasses to the atmosphere, thus, contributing to further atmospheric warming. In northeastern China, near the Siberian border, some documented landslides raised concerns about the safety of a segment along the National Highway 202. The study by Shan et al. (2015) hypothesized that permafrost melting drives the occasional landslides in the area. Shan et al. (2015) fell short of demonstrating the impact of climate-driven permafrost melting as the landslide trigger in their study area. The authors attempted to link permafrost thawing to the significant rapid increase in average minimum air temperatures compared to the average maximum temperatures. These asymmetric rates lead to a declining diurnal temperature range (DTR), considered as an important indicator of climate change (Qu et al., 2014). The authors recognized the presence of human construction activities in the area but made no attempt to rule these out as landslide triggers. The study also seems perplexed in attributing whether permafrost thawing is the cause or effect of the signature DTR trends. Despite presenting pieces of evidence, the authors did not convincingly show that permafrost thawing, due to climate change, significantly induced landslides. Declining DTR appears widespread, even in latitudes too low for permafrost to exist. Between 1911 and 2012, the annual mean DTR has been falling across all regions in the continental United States. For example, at low-latitude Tucson, AZ, Comrie (2000) found evidence for a declining DTR between 1949 and 2005. The Daqing River Basin, south of Beijing, where permafrost obviously does not exist, also exhibit DTR downtrends between 1961 and 2010. Concerning seasonal averages, winter DTRs appear to decline the most (Liu et al., 2014). In contrast, Shan et al. (2015, p. 9) attribute the observed DTR downtrend in Sunwu County particularly to