A comparative analysis of China's anthropogenic CO2 emissions (2000-2023): Insights from six bottom-up inventories and uncertainty assessment

Abstract

Accurate quantification of anthropogenic CO2 emissions is crucial for mitigating climate change and verifying emission reduction policies. This study conducts a comparative analysis of China's anthropogenic CO2 emissions for the period between 2000 and 2023 based on six widely used bottom-up inventories at their latest version (ODIAC2023, EDGAR2024, MEIC-global-CO2 v1.0, CAMS-GLOB-ANT v6.2, GEMS v1.0, and CEADs). The national total CO2 emissions increase from 3.43 (3.21-3.63) Gt yr-1 in 2000 to 12.03 (11.35-12.98) Gt yr-1 in 2023, with three growth periods: rapid growth (2000-2013, 0.56 ± 0.013 Gt yr-1), near-stagnation (2013-2016, -0.07 ± 0.022 Gt yr-1), and renewed growth (2016-2023, 0.30 ± 0.016 Gt yr-1). Emissions are dominated by the electricity and heat production, and the industry and construction (78 % of total emissions), with the former replacing the latter as the largest source after 2017. EDGAR consistently reports the highest national CO2 emissions, while MEIC provides the lowest, contributing to the large deviations after 2012. EDGAR and MEIC report different spatial distributions of the transport sector. EDGAR concentrates emissions along major roads and MEIC distributes them more diffusely. Extreme outliers (> 105 t CO2 km-2 yr-1, against an average of 102 t CO2 km-2 yr-1) in these inventories arise from discrepancies in point source data in the Carbon Monitoring for Action (CARMA) versus the China Power Emissions Database (CPED). Overall, the uncertainty of total national anthropogenic CO2 emissions is within 5 % (1σ), and the uncertainties are about 10 %-50 % (1σ) at the provincial level. Our study underscores that the improved spatial proxies, consistent regional inventories, and continued methodological updates are essential for improving the robustness of China's CO2 emission assessments and supporting mitigation planning.