China city-level greenhouse gas emissions inventory in 2015 and uncertainty analysis

Accounting and understanding greenhouse gas (GHG) emissions at the city level are of great importance because cities are the focus of future mitigation and adaption activities to address climate change, especially in developing nations like China. However, existing studies have not yet provided a complete and updated emissions inventory of city-level GHGs for China in terms of city and GHG-type coverage. In this paper, we rigorously assemble a dataset that contains GHG emissions including carbon dioxide, methane, nitrous oxide, and fluorinated GHGs for 305 Chinese cities, based on a high-resolution emissions database (China High-Resolution Emission Database, CHRED 3.0) and first-hand on-site data collection and verification by 19 groups of 137 researchers using a bottom-up method, and analyze the uncertainty of the emissions. Results show that total GHG emissions are high in cities in eastern China and low in cities in west, while per capita GHG emissions are high in northern cities and low in southern cities. The emissions of four types of GHGs (CO2, CH4, N2O and fluoridated GHGs) share different spatial distributions, due to variant industrial structure, energy structure, industry point sources and agricultural surface sources, etc. The uncertainty of GHG emissions is highly related to the source data of cities. Finally, we propose policy recommendations, including improving data quality and strengthening competitions of city-level emission reduction, to improve city-level emissions data integrity and low-carbon development strategies.