Comparing estimates of SO2 and NOx emissions inventories for the U.S. and China: exploring the reasons for discrepancies between EDGAR and ECLIPSE

Abstract

The EDGAR and ECLIPSE datasets contain estimates of past, current, and future emissions of greenhouse gases and other air pollutants, at the global, regional and national scales. These datasets are each a direct output of two models. This project compares the estimates of Nitrogen oxides (NOx) and Sulfur dioxide (SO2) for years 2000, 2005 and 2010 reported by ECLIPSE and EDGAR for the United States and China in order to examine the underlying assumptions and modeling structures and understand the sources of any differences between the two datasets. Results show that while global estimates from the two datasets are similar, there are noticeable discrepancies at the national level. These differences are due to the different ways each productive sector of the economy is grouped in order to estimate emissions, the different sources of information used to compile the datasets, and different underlying assumptions of each dataset. This study finds that the transportation sector is the driver of significant differences in estimates of both global and national NOx emissions and energy sector data at the regional level.