Promoting the Achievement of Carbon Neutrality Targets: Systematic Review of Research Dimensions and Measure Methods on Carbon Equity in China

Carbon equity is the balance between carbon reduction responsibilities and development rights. The review of carbon equity in China can help it achieve carbon neutrality targets and provide valuable insights to other emerging countries. This study aimed to systematically sort, classify, compare, and prospect the research dimensions and measure methods for carbon equity. The research dimensions were first classified into intergenerational, regional, trade, and income carbon equity by literature analysis. Intergenerational carbon equity explores the balance of carbon emission rights among generations using integrated assessment models (IAM). Regional carbon equity analyzes the socioeconomic effect of regional carbon emission rights allocation by IAM or regional differences under a specific allocation assumption by the Theil index. Trade carbon equity studies the relationship between carbon emissions and economic benefit transfer embodied in inter-regional trade, which is more suitable for calculating by methods with comparable results, such as the optimized regional environmental inequality index. Income carbon equity investigates the carbon footprint heterogeneity among income groups by the carbon Gini coefficient. This paper further discusses potential research directions for each dimension. Notably, all research dimensions did not consider promoted strategies for carbon equity, which should be a priority for future studies.