Consultant report

Investigation of Diesel Emissions in China

In 2012, the International Council on Clean Transportation supported Tsinghua University to investigate emission factors of diesel vehicles in China. The project included a careful review and summary of all available existing on-road emissions data for China (over 300 vehicles), new PEMS (Portable Emissions Measurement System) measurements of twenty older diesel vehicles, and comparison of real-world emissions data against existing inventory studies.

The results of the study convincingly demonstrate that more stringent tailpipe emission standards in China have resulted in dramatic reductions in emission factors for CO, HC, and PM, but not for NOx. Policy evaluations which assume a continuous decrease in NOx emission factors as standards have been tightened almost certainly significantly underestimate total emissions in China.

One conclusion of the report is that the Chinese government needs to enforce stricter NOx standards for diesel vehicles in order to achieve the national target of reducing NOx emissions by 10% during the 12th Five-Year Plan (2011–2015).

ICCT staff contact: Vance Wagner