Evaluating the co-control potential of CO2 and air pollutant emission reductions in the cement industry in China: A case in Henan

China, as the world's largest cement producer, faces enormous pressure to co-control energy consumption, CO₂ emissions, and air pollution. Taking Henan Province as an example, this study proposes an integrated bottom-up framework combining cement demand forecasting, energy-carbon-pollutant emission accounting, cross-elasticity coefficients, and conservation supply curves to quantify the co-control potential, synergies, and cost-effectiveness across seven strategies. Results show: (1) Plate-level data reveal that Henan's cement sector emitted 54.38 Mt CO₂ in 2022 (93 % from clinker calcination), with 61 % of clinker plants exceeding ultra-low NO_x standards and 45 % of grinding stations surpassing PM limits. (2) The integrated scenario achieves the highest co-control potential by reducing CO₂ and local air pollutant (LAP) emissions by 80 % from 2022 levels by 2050 at a net cost of 1.27 billion CNY (Chinese Yuan) while accounting for monetized co-benefits. (3) Production reduction is the key factor in lowering total emissions. Cement and clinker outputs will drop to 49 % and 44 % of base-year levels with supply-demand interventions, contributing to 65 % of final CO₂ and LAP emission reductions. (4) Energy-related strategies provide significant co-control benefits, contributing 14 % to CO₂ reductions and 25 % to LAP reductions, with cumulative benefits of 17.96 billion CNY. (5) Material substitution is pivotal for deep decarbonization, accounting for 10 % of CO₂ reductions and 9 % of LAP cuts, with cumulative benefits of 5.29 billion CNY. Although carbon capture, utilization and storage is indispensable for carbon neutrality, contributes 11 % to CO₂ mitigation, it increases LAP by 1 % at a cost of 22.14 billion CNY. The research results provide a reference for developing effective co-control strategies and offer actionable insights for other provinces' green and low-carbon transition.