Zhong Junting, Zhang Xiaoye, Guo Lifeng, Wang Deying, Miao Changhong, Zhang Xiliang
Monitoring and Assessment Center for Greenhouse Gases and Carbon Neutrality, Key Laboratory of Atmospheric Chemistry of China Meteorological Administration, Chinese Academy of Meteorological Sciences, Beijing 100081, China; Laboratory of Climate Change Mitigation and Carbon Neutrality, Henan University, Zhengzhou 450001, China.
Monitoring and Assessment Center for Greenhouse Gases and Carbon Neutrality, Key Laboratory of Atmospheric Chemistry of China Meteorological Administration, Chinese Academy of Meteorological Sciences, Beijing 100081, China; Laboratory of Climate Change Mitigation and Carbon Neutrality, Henan University, Zhengzhou 450001, China.
Sci Bull (Beijing). 2023 Oct 30;68(20):2467-2476. doi: 10.1016/j.scib.2023.08.039. Epub 2023 Aug 21.
Accurate estimating CO emissions and sinks is crucial in achieving carbon neutrality in China. However, CO emissions from bottom-up inventories are uncertain at regional scales and lack independent verification from atmospheric perspectives. Here we integrated 39 high-precision CO stations in China to top-down invert emission-sink variations at 45 km × 45 km and achieved a full range of inventories verification. The results show that China's CO emissions are 15% higher than those of five bottom-up inventories, to an annual total of 3.40 Pg C a for 2018-2021. After deducting human and livestock respiration, the annual CO emissions were 3.13 Pg C a (11.48 Pg CO a). The annual increase in emissions slowed from 3.7% in 2019 to 1.1% in 2020 and resumed growth to 4.0% in 2021, consistent with observed CO growth rates in China. China's land CO sink, deducting farmland sinks and lateral fluxes, was 0.57 Pg C a (2.09 Pg CO a) for 2018-2021 (higher than most global inverse models), accounting for ∼16.9% of anthropogenic CO emissions. The land sink in China decreased by -19.3% in 2019 due to a weak El Niño event and increased by 3.2% in 2020 and 13.7% in 2021. It is worth noting that inverse CO emissions and sinks in western China still face large uncertainty due to limited CO monitoring. Overall, our top-down estimates demonstrate spatiotemporal variations in CO emissions and sinks from atmospheric perspectives and highlight challenges for different provinces in achieving 2060 carbon neutrality with verified estimates.
准确估算一氧化碳（CO）排放和汇对于中国实现碳中和至关重要。然而，自下而上清单中的CO排放在区域尺度上存在不确定性，且缺乏从大气角度的独立验证。在此，我们整合了中国39个高精度CO监测站，以自上而下的方式反演45 km×45 km网格上的排放-汇变化，并实现了对清单的全面验证。结果表明，中国的CO排放量比五个自下而上清单的排放量高15%，2018 - 2021年的年排放总量为3.40 Pg C a。扣除人畜呼吸作用后，年CO排放量为3.13 Pg C a（11.48 Pg CO a）。排放年增长率从2019年的3.7%放缓至2020年的1.1%，并在2021年恢复增长至4.0%，这与中国观测到的CO增长率一致。2018 - 2021年，扣除农田汇和侧向通量后，中国陆地CO汇为0.57 Pg C a（2.09 Pg CO a）（高于大多数全球反演模型），约占人为CO排放量的16.9%。由于弱厄尔尼诺事件，中国陆地汇在2019年下降了-19.3%，在2020年增加了3.2%，在2021年增加了13.7%。值得注意的是，由于CO监测有限，中国西部的反演CO排放和汇仍面临较大不确定性。总体而言，我们的自上而下估算从大气角度展示了CO排放和汇的时空变化，并凸显了不同省份在以经过验证的估算实现2060年碳中和方面面临的挑战。
