Progress of research on energy-related carbon emission accounting methods at the prefectural and county levels

Abstract

Carbon emission accounting of prefectural and county units is the basic work of emission reduction research. Due to the lack of energy data, scholars in China and abroad have proposed many carbon emission accounting methods at the prefectural and county levels. Existing accounting methods lack comparative analysis and systematic summary. To provide a scientific reference for researchers to choose appropriate accounting methods, this study reviewed relevant literature in China and internationally from 2000 to 2022, classified prefectural and county scale carbon emission accounting methods, and discussed the advantages and disadvantages of these methods and their scope of application. The main results and conclusions are as follows: 1) There are two types of accounting methods for the prefectural and county units—inventory and nighttime light data inversion. 2) The inventory methods include the top-down decomposition method, which allocates energy consumption to target units according to the proportion of the output value of each sector in the corresponding sector at the provincial level; the bottom-up method, obtaining energy data and carbon emission accounting by sector; and the combination of the top-down and bottom-up methods, which combines the available sectoral energy data with the decomposition of energy data, taking into account the feasibility of accounting work. 3) Nighttime light inversion methods include the equation parameter downscaling conduction method, which was used to construct the regression model of light brightness and total carbon emissions of different scale units in a province; and downscaling decomposition method, which takes the proportion of total nighttime light brightness in the provincial unit as the weight to decompose the provincial carbon emissions into the administrative unit at the lower level. 4) The scope of application of different methods was discussed from the aspects of spatial scale and research content. An important future development direction of carbon accounting methods is to conduct carbon emission accounting at the prefectural and county levels, investigate the energy consumption of typical prefectural/county units, and use them as samples to construct inversion equation models of nightlight brightness and carbon emissions.