Carbon Emission Measurement and the Decoupling Effect Under the "Double Carbon" Goal in Xi'an, China

Cities generate more than 60% of carbon emissions and are the main battleground for achieving the target. However, there is no unified and standardized measurement methods of carbon emissions in cities. In this paper, we took Xi'an as an example and started by measuring carbon emissions with the new standards. Then, the decoupling of economic development from carbon emissions was studied according to the Tapio decoupling theory. Based on the generalized Divisia index method, the decoupling effort model was proposed to study the impact of carbon emission factors contributing to carbon reduction. The results show: (ⅰ) During the period 1995–2021, the carbon emissions of Xi'an increased rapidly, with an average annual growth rate of 6.06%, due to the accelerating pace of urbanization and industrialization. (ⅱ) The energy consumption sector accounted for the largest share of carbon emissions, ranging from 77.38% to 89.46%. Xi'an's energy structure is primarily based on fossil fuels, especially coal, which holds a significant proportion. To achieve the "double carbon" goal, it is crucial to reduce the dependence on fossil fuels. (ⅲ) The 10th Five-Year Plan was in the state of "expansive coupling", while other periods were in the "weak decoupling" state from the 9th to 14th Five-Year Plan periods. After the carbon peak year in the 15th Five-Year Plan, it would be in a state of "strong decoupling". The agricultural production account was the first to achieve a "strong decoupling" state. (ⅳ) The government of Xi'an made efforts to decouple, but these were not enough. Technological innovation played a crucial role in the carbon reduction of Xi'an, and was a key factor in achieving the "double carbon" goal.