Spatial and Temporal Variations of Atmospheric CO₂ Concentration in China and Its Influencing Factors

• Main Authors: Zhenghan Lv, Yusheng Shi, Shuying Zang, Li Sun
• Format: Article
• Language: English
• Published: MDPI AG 2020-02-01
• Series: Atmosphere
• Subjects: carbon dioxide (co2); gosat; spatial variation; temporal trends; influencing factors
• Online Access: https://www.mdpi.com/2073-4433/11/3/231

Over the past few decades, concentrations of carbon dioxide (CO₂), a key greenhouse gas, have risen at a global rate of approximately 2 ppm/a. China is the largest CO₂ emitter and is the principle contributor to the increase in global CO₂ levels. Based on a satellite-retrieved atmospheric carbon dioxide column average dry air mixing ratio (XCO₂) dataset, derived from the greenhouse gas observation satellite (GOSAT), this paper evaluates the spatial and temporal variations of XCO₂ characteristics in China during 2009&#8722;2016. Moreover, the factors influencing changes in XCO₂ were investigated. Results showed XCO₂ concentrations in China increased at an average rate of 2.28 ppm/a, with significant annual seasonal variations of 6.78 ppm. The rate of change of XCO₂ was greater in south China compared to other regions across China, with clear differences in seasonality. Seasonal variations in XCO₂ concentrations across China were generally controlled by vegetation dynamics, characterized by the Normalized Difference Vegetation Index (NDVI). However, driving factors exhibited spatial variations. In particular, a distinct belt (northeast&#8722;southwest) with a significant negative correlation (<i>r</i> &lt; &#8722;0.75) between XCO₂ and NDVI was observed. Furthermore, in north China, human emissions were identified as the dominant influencing factor of total XCO₂ variations (<i>r</i> &gt; 0.65), with forest fires taking first place in southwest China (<i>r</i> &gt; 0.47). Our results in this study can provide us with a potential way to better understand the spatiotemporal changes of CO₂ concentration in China with NDVI, human activity and biomass burning, and could have an enlightening effect on slowing the growth of CO₂ concentration in China.