In order to track progress towards the global climate targets, the parties that signed the Paris Climate Agreement
10 will regularly report their anthropogenic carbon dioxide (CO2) emissions based on energy statistics and CO2 emission factors. Independent evaluation of this self-reporting system is a fast-growing research topic. Here, we study the value of satellite observations of the column CO2 concentrations to estimate CO2 anthropogenic emissions with five years of the Orbiting Carbon Observatory-2 (OCO-2) retrievals over and around China. With the detailed information of emission source locations and the local wind, we successfully observe CO2 plumes from 60 cities and industrial regions over China and
15 quantify their CO2 emissions from the OCO-2 observations, which add up to a total of 1.6 Gt CO2 yr−1 that account for 17% of mainland China’s annual emissions. The number of cities whose emissions are constrained by OCO-2 here is three to ten times larger than previous studies that only focused on large cities and power plants in different locations around the world. Our satellite-based emission estimates are broadly consistent with the independent values from the detailed China’s emission inventory MEIC, but are more different from those of two widely used global gridded emission datasets (i.e., EDGAR and
20 ODIAC), especially for the emission estimates for the individual cities. These results demonstrate some skill in the satellitebased emission quantification for isolated source clusters with the OCO-2, despite the sparse sampling of this instrument not designed for this purpose. This skill can be improved by future satellite missions that will have a denser spatial sampling of surface emitting areas, which will come soon in the early 2020s.