Global warming may degrade the permafrost in the Qinghai Tibet Plateau

"Global warming has caused or is causing serious degradation of Permafrost on the Qinghai Tibet Plateau, partially changing the thermal state of permafrost." The team of Ran Youhua, Li Xin and Cheng Guodong from the remote sensing and Geographic Information Research Office of Northwest Institute of ecological environment and resources, Chinese Academy of Sciences and the extraordinary innovation center of Earth Sciences on the Qinghai Tibet Plateau recently announced the news.

The team used the geographically weighted regression model, integrated remote sensing surface temperature, leaf area index, snow cover ratio, multi model soil moisture prediction and other indicators, combined with the precipitation observation of more than 40000 meteorological stations and the annual average temperature observation data of 152 meteorological stations in the past 50 years, and simulated the annual average temperature of 1km on the Qinghai Tibet Plateau in the past five 10 years. Using the thermal condition classification system of permafrost, the thermal degradation of permafrost in Qinghai Tibet Plateau in the past 50 years is analyzed.

It is found that the annual average temperature of the Qinghai Tibet Plateau has continued to rise at the rate of 0.04 ℃ per year in the past half century. The warming rate in the west of the plateau is higher than that in the East. The warming rate increases by about 0.33 ℃ every 10 years from 4000 meters to 5000 meters. Over the past 50 years, 87.98% of the permafrost areas on the Qinghai Tibet Plateau have undergone thermal degradation. The average altitude of permafrost that is very cold, cold, cool, warm, very warm and may thaw has increased by 88 meters, 97 meters, 155 meters, 185 meters, 161 meters and 250 meters respectively. The 1960s to 1970s and the 1990s to the first decade of this century are two key degradation periods.

The study shows that the total area of Permafrost on the Qinghai Tibet Plateau is about 1111300 to 1279700 square kilometers, and it is mainly very warm permafrost. "The thermal degradation of permafrost may have an important impact on infrastructure security, ecosystem resilience, water quality and global and regional climate." The team leader thinks.