A carbon-neutrality-capactiy index for evaluating carbon sink contributions

Xiaoyong Bai; Sirui Zhang; Chaojun Li; Lian Xiong; Fengjiao Song; Chaochao Du; Minghui Li; Qing Luo; Yingying Xue; Shijie Wang

doi:10.1016/j.ese.2023.100237

A carbon-neutrality-capactiy index for evaluating carbon sink contributions

Environ Sci Ecotechnol. 2023 Jan 9:15:100237. doi: 10.1016/j.ese.2023.100237. eCollection 2023 Jul.

Authors

Xiaoyong Bai^{1

2

3}, Sirui Zhang¹, Chaojun Li¹, Lian Xiong^{1

2}, Fengjiao Song¹, Chaochao Du^{1

2}, Minghui Li^{1

2}, Qing Luo^{1

2}, Yingying Xue^{1

2}, Shijie Wang¹

Affiliations

¹ State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China.
² School of Geography and Environmental Sciences, Guizhou Normal University, Guiyang, 550001, Guizhou Province, China.
³ CAS Center for Excellence in Quaternary Science and Global Change, Xi'an, 710061, Shaanxi, Province, China.

Abstract

The accurate determination of the carbon-neutrality capacity (CNC) of a region is crucial for developing policies related to emissions and climate change. However, a systematic diagnostic method for determining the CNC that considers the rock chemical weathering carbon sink (RCS) is lacking. Moreover, it is challenging but indispensable to establish a fast and practical index model to determine the CNC. Here, we selected Guizhou as the study area, used the methods for different types of carbon sinks, and constructed a CNC index (CNCI) model. We found that: (1) the carbonate rock chemical weathering carbon sink flux was 30.3 t CO₂ km^-2 yr^-1. Guizhou accounted for 1.8% of the land area and contributed 5.4% of the carbonate chemical weathering carbon sink; (2) the silicate rock chemical weathering carbon sink and its flux were 1.44 × 10³ t CO₂ and 2.43 t CO₂ km^-2 yr^-1, respectively; (3) the vegetation-soil ecosystem carbon sink and its flux were 1.37 × 10⁸ t CO₂ and 831.70 t CO₂ km^-2 yr^-1, respectively; (4) the carbon emissions (CEs) were 280 Tg CO₂, about 2.8% of the total for China; and (5) the total carbon sinks in Guizhou were 160 Tg CO₂, with a CNCI of 57%, which is 4.8 times of China and 2.1 times of the world. In summary, we conducted a systematic diagnosis of the CNC considering the RCS and established a CNCI model. The results of this study have a strong implication and significance for national and global CNC determination and gap analysis.

Keywords: Carbon budget; Carbon neutrality; Carbon sink; Carbon source; Rock chemical weathering.