Trends of energy-related CO2 emissions from non-ferrous metal smelting in China: Multi-factor analysis and emission reduction potential

To achieve climate goals, China needs to promote low-carbon development in non-ferrous metal smelting. This study is the first to analyze the trend of CO2 emissions from major non-ferrous metal smelting in China based on government planning and advanced technology. It innovatively decomposes CO2 emissions into carbon emission factor factors, technological improvement factors, proportion of recycled metal factors, and production factors. The results indicate that: (1) The rapid growth in production increased total CO2 emissions from the major non-ferrous metals smelting by 137.34 Mt over 2010–2020. (2) The peak of CO2 emissions from non-ferrous metal smelting in the multi-factor scenario analysis occurs between 2021 and 2025, and the HBN scenario has the latest peak year, with an emission of 446.37 Mt (3) ΔCF is the largest contributor to reduce CO2 emissions from four non-ferrous smelting in the HBN scenario, benefiting from a higher proportion of clean energy generation and a decline in standard coal consumption for thermal power supply. (4) ΔPS is the first driver from lead smelting and the second driver from aluminum smelting for CO2 reduction in the LAM scenario, and the recycling of scrap non-ferrous metals is an important means to reduce CO2 emissions. The results provide guidance for different non-ferrous metals to control the production expansion, promote the recycled metals development, and enhance technological improvement.