Impact of demographic changes on carbon emissions under a carbon-neutral pathway

The existing carbon–neutral oriented climate change policy modeling studies hardly consider the multidimensional demographic factors, and lack scientific understanding of the comprehensive impact of changes in demographic factors on future carbon emissions in the medium and long term. In this study, we constructed a dataset of China's future medium and long–term demographic changes by urban and rural areas, age, gender, and education level through multidimensional iterative modeling. Then a computable general equilibrium model of China's multiregional population dynamics model was constructed, and various counterfactual scenarios were designed to analyze the impacts of carbon emissions from changes in population size and demographic structure and their mechanisms under a carbon–neutral pathway. The results show that under the multifactor demographic, the national CO 2 emissions peak at 9.93 Gt in 2030 in the baseline scenario and continue to decline between 2030 and 2060, leaving 1.97 Gt of CO 2 emissions in 2060 without considering negative emissions technologies. The fossil power generation sector is the main contributor to CO 2 emission reductions in the long–term timeframe beyond 2030. Considering only changes in population size and ignoring demographic changes would overestimate national carbon emissions, 1.0% (100 Mt) of CO 2 emissions would be overestimated in 2030, and 7.5% (160 Mt) in 2060. By 2060, ignoring demographic changes on the consumption side overestimates national carbon emissions by 1.15%, while on the production side, ignoring demographic impacts on labor supply would overestimate them by 6.2%. On the production side, changes in the age structure of the population and increases in educational attainment are the main factors, leading to a 16.5% decrease and 10% increase in national carbon emissions, respectively.