Deciphering the CO2 emissions and emission intensity of cement sector in China through decomposition analysis

China produced over half of the global cement for its building and infrastructure construction and released huge amount of greenhouse gases. Despite a significant penetration of the new suspension pre-calciner (NSP) kilns was reported to benefit emission abatement in the past, whether CO2 emissions has peaked and would some recent structural changes affect the low-carbon transition in China are yet to be investigated. Thus, this study develops a three-step framework to estimate the CO2 emissions and investigate the socio-economic emission drivers and the recent structural change of the cement sector in China during 1990-2020. Results reveal that CO2 emissions from cement production have yet peaked in China, as it increased again after the sharp decline in 2015. The aggregate emission intensity of cement production significantly decreased from 708.5 to 485.3 kg CO2/t during 2000-2015 with the penetration of the NSP kilns, but after that it rebounded to 548.6 kg CO2/t. The decomposition analysis reveals that the inter-sector impacts outweighed the intra-sectoral mitigation effects in the past three decades, and further decoupling analysis also reveals that the total emissions have yet been decoupled with economic development. Also, the rebound in emission intensity is attributed to the rebound in the clinker-to-cement ratio, which is further due to the recent abolishment of low-grade cement and expanding production of higher-grade cement. A 'reduce' approach, such as reducing construction activities and improving material efficiency, would be a much more effective policy option for short to medium term low-carbon transition, rather than merely implementing the intra-sectoral measures.

Automated summary

China's CO2 emissions from cement production have not yet peaked, and recent structural changes have led to a rebound in emission intensity. Over the past three decades, inter-sector impacts have outweighed intra-sectoral mitigation effects. To achieve low-carbon transition, adopting a "reduce" approach such as reducing construction activities and improving material efficiency is a more effective policy option.