Change trend of natural gas hydrates in permafrost on the Qinghai-Tibet Plateau (1960–2050) under the background of global warming and their impacts on carbon emissions

• Published in: China Geology
• Main Authors: Zhen-quan Lu, Chu-guo Wu, Neng-you Wu, Hai-long Lu, Ting Wang, Rui Xiao, Hui Liu, Xin-he Wu
• Format: Article in Journal/Newspaper
• Language: English
• Published: KeAi Communications Co., Ltd. 2022
• Subjects: Climate change; Global warming; Permafrost; Gas hydrate; Greenhouse effect; Carbon emission; Engineering (General). Civil engineering (General); TA1-2040; Geology; QE1-996.5; permafrost
• Online Access: https://doi.org/10.31035/cg2022034; https://doaj.org/article/eec73a23370e42d9b7230c575f0cefda

Global warming and the response to it have become a topic of concern in today’s society and are also a research focus in the global scientific community. As the world’s third pole, the global warming amplifier, and the starting region of China’s climate change, the Qinghai-Tibet Plateau is extremely sensitive to climate change. The permafrost on the Qinghai-Tibet Plateau is rich in natural gas hydrates (NGHs) resources. Under the background of global warming, whether the NGHs will be disassociated and enter the atmosphere as the air temperature rises has become a major concern of both the public and the scientific community. Given this, this study reviewed the trend of global warming and accordingly summarized the characteristics of the temperature increase in the Qinghai-Tibet Plateau. Based on this as well as the distribution characteristics of the NGHs in the permafrost on the Qinghai-Tibet Plateau, this study investigated the changes in the response of the NGHs to global warming, aiming to clarify the impacts of global warming on the NGHs in the permafrost of the plateau. A noticeable response to global warming has been observed in the Qinghai-Tibet Plateau. Over the past decades, the increase in the mean annual air temperature of the plateau was increasingly high and more recently. Specifically, the mean annual air temperature of the plateau changed at a rate of approximately 0.308–0.420°C/10a and increased by approximately 1.54–2.10°C in the past decades. Moreover, the annual mean ground temperature of the shallow permafrost on the plateau increased by approximately 1.155–1.575°C and the permafrost area decreased by approximately 0.34×106 km2 from about 1.4×106 km2 to 1.06×106 km2 in the past decades. As indicated by simulated calculation results, the thickness of the NGH-bearing permafrost on the Qinghai-Tibet Plateau has decreased by 29–39 m in the past 50 years, with the equivalent of (1.69 – 2.27)×1010–(1.12–1.51)×1012 m3 of methane (CH4) being released due to NGHs dissociation. It is predicted that ...