Changes of Atmospheric CO₂ in the Tibetan Plateau From 1994 to 2019

Abstract

The emission of greenhouse gases (GHGs) has increased rapidly since the pre-industrial era (1750 C.E.). The concentration of GHGs in the atmosphere has reached a historic level, inducing various unwanted phenomena, such as global warming, glacier melting, and extreme weather events (IPCC, 2014). Among the primary GHGs [water vapor, carbon dioxide (CO 2 ), methane, nitrous oxide, and ozone], CO 2 is the most important as it has strong infrared absorption and contributes ∼66% of the radiative forcing by long-lived GHGs (Stuiver & Quay, 1981). Currently, sources/sinks and biogeochemical cycling of CO 2 play an important role in global climate change, and their abundance is considered to further continue being a dominant factor for future climate change (Albritton et al., 2001;Li et al., 2014). According to the IPCC AR5 Synthesis Report, the global mean surface temperature in the late twenty-first century would be largely determined by the cumulative emission of CO 2 (IPCC, 2014). Ice core studies reveal that the atmospheric CO 2 mole fraction was only approximately 278 ppm around 1750 C.E.

Monitoring greenhouse gases (GHGs) in China: status and perspective

“…In addition to the network-based routine observations, there are also many research-oriented GHGs campaigns around the globe, and these uncoordinated behaviors are too numerous to count accurately (Gerbig et al, 2003;Lin et al, 2006;Zellweger et al, 2016;Gomez-Pelaez et al, 2019;Liu et al, 2021a;Liu et al, 2021b).…”

“…Facing one of the most serious climate change problems around the globe, China has to address a series of scientific, technical, and management issues to achieve the goals of carbon peak/neutrality. As China pays more and more (Tian et al, 2017;Tian et al, 2018;Wang et al, 2019;Li et al, 2021;Liu et al, 2021b), in background areas such as Waliguan in Qinghai Province and Longfengshan in Heilongjiang Province (Fang et al, 2014;Fang et al, 2015a;Fang et al, 2016), and in offshore areas such as the South China Sea, Yellow Sea, and Bohai Bay (Gerbig et al, 2003;Liu et al, 2021a;Liu et al, 2021b).…”

“…All these techniques can be classified as spectroscopic technique except EC technology, which uses capacitive readout cantilevers to detect an absorbed signal (Zellweger et al, 2016;Liu et al, 2022). (Fang et al, 2014;Tian et al, 2017;Wang et al, 2017;Yang et al, 2020c;Liu et al, 2021a;Liu et al, 2021b;Sun et al, 2021).…”

“…A series of in situ online, ground-based, and airborne instruments have been developed by Chinese scientists to investigate the diurnal, monthly, seasonal, and interannual variabilities and spatial distributions of key GHGs (Tang et al, 2006), speculate their sources and sinks, and reveal the physical and chemical mechanisms that drive their variabilities. For example, Chinese scientists have developed a suite of in situ spectroscopic instruments to measure surface VMRs and isotope ratios of GHGs in background atmosphere, sea-air CO2 flux in coastal ocean boundary layer, and soil-air CO2 flux in farmland (Gerbig et al, 2003;Liu et al, 2021a;Liu et al, 2021b) total columns of GHGs (Tian et al, 2018), vehicle-based spectroscopic instruments for industrial GHGs emissions, and airborne spectroscopic instruments for deriving the spatial distributions of CO2 in the North China Plain (Wang et al, 2019;Shi et al, 2021).…”

“…4. Some Chinese scientists have used the commercial in situ instruments such as Picarro or Licor series GHGs analyzers to investigate the spatiotemporal variabilities and emission flux of GHGs in different regions of China (Lin et al, 2006;Tang et al, 2006;Fang et al, 2016;Tian et al, 2018;Li et al, 2021;Liu et al, 2021b). With the public accessible OCO-2 satellite data, Chinese scientists have estimated CO2 anthropogenic emissions of cities and industrial regions in China.…”