Empirical assessing cement CO₂ emissions based on China's economic and social development during 2001-2030

Cement industry is a large emitter of carbon dioxide (CO₂), taking up 5-8% of anthropogenic CO₂ emissions. China is the largest developing country in the world. With the fast urbanization rate, economic growth and rapid development of industry, China's cement production is soaring year by year. Also, cement CO₂ emissions increased year by year and aroused the rising attention. However, the historical province- and nation-level cement production situations, driving forces of cement output and/or demand based on rapid economic growth and urbanization rate, the peak of cement consumption and China's cement demand projection and CO₂ emissions through 2030 when China should fulfill the international commitments were not clear. The present study summarized the characteristics of China's cement production and CO₂ emissions during 2001-2015, projected cement CO₂ emission scenarios based on diffusion of alternative materials and technical innovation toward 2030. The following results were summarized, clinker- and cement- CO₂ emission factors (EFs) were declining year by year with the technical innovation. CO₂ emissions increased with the increase of cement output year by year. The discrepancies of CO₂ emissions from different researches were becoming large year by year, and the biggest difference of CO₂ emissions reached 49% in 2015. Accordingly, we recommended active EFs for the calculation of cement CO₂ emissions. Cement production situation varies greatly with province, as manifested in unbalanced NSP technology and clinker-to-cement ratio, and energy consumption, which was primarily attributed to the unbalanced resource reserves and economic development. There is still sufficient room for CO₂ reduction in China's cement industry, and the use of alternative material was better than technical innovation in such reduction. The optimal emissions in 2030 will be 1490 Mt CO₂. And China's cement consumption will be stable in 2030, cumulative cement consumption per capita will be peaked at 23394 kg, and UR will reach 70.1%.