Impacts of Apparent Uncertainties in Energy Statistics on China’s Emission Estimates

Abstract:

The accuracy of China’s energy statistics is of great concern as it contributed greatly to the uncertainties in estimates of global emissions. This study attempts to improve the understanding of uncertainties in China’s energy statistics and evaluate its impacts to China’s emissions for the period 1990-2010. We use the MEIC (Multi-resolution Emission Inventory for China) model to calculate emissions with different official energy statistics datasets. Emission trends were then verified by satellite observations using the approach of Lamsal et al. (2011) to include the non-linear relationship between changes in tropospheric NO₂ columns and NO_x emissions. We found that the apparent uncertainties in China’s energy statistics were expanded in recent years, and coal contributed more than 90% of these uncertainties. The emissions calculated from the provincial energy statistics are generally higher than that from the national energy statistics, and the discrepancies are 27.3%, 17.5%, 14.1%, 8.0% and 8.0% for SO₂, NOx, CO₂, VOC and PM_2.5 in 2010, respectively. SO₂ emissions are most sensitive to uncertainties in energy consumption due to high contributions from industrial coal combustions. The emission trends vary significantly among differ energy statistics, and a slower NOx growth rate (about 25%) from 2005 to 2010 are found both from the national energy statistics and from OMI satellite observations, whereas the provincial energy statistics show higher growth rate (40%), raising the doubts about the data reliability of provincial energy statistics in recent years.