A top-bottom estimation method for city-level energy-related CO2 emissions

Due to the fast process of urbanization in China recently, rapid growth of urban carbon emissions has been greatly brought about, it's generally recognized that accurate city-level carbon emission data are crucial for formulating scientific and reasonable carbon emission reduction policies. By clarifying the key categories of carbon emission sources, different kinds of carbon emissions can be targeted and precisely controlled. However, recent researches on carbon emissions were mainly concentrated at the national, regional and provincial levels, and due to the opacity and inaccuracy of the required basic data, complete carbon emission inventories for general prefecture cities have not been well compiled for a long period. To solve the problem, on the basis of previous studies, the provincial energy balance table and reasonable distribution indicators are used to estimate carbon emissions in subordinate cities from provincial carbon emissions data in our research, and a set of top-bottom urban energy consumption carbon emission estimation methods was constructed. The comparison with the publicly available city level carbon emission database showed that the estimation gap was all within 10%, which proved the feasibility and accuracy of the method. We also tried to extend the method on the time scale and provide the validation. This paper provided a scientific method and reasonable ideas for acquiring carbon emissions data of Chinese cities that were continuous in both time and space scale, and could also provide reliable data support for allocating carbon emission reduction tasks and emission reduction consultations between cities. © 2019, Editorial Board of China Environmental Science. All right reserved.