UNECE has been contributing to climate change mitigation through different activities. In the framework of the World Forum for Harmonisation of Vehicle Regulations (WP.29), it develops regulations increasing vehicles’ energy efficiency and lowering emissions. Emission limits for gaseous pollutants have been reduced in the last decades by more than 95 per cent compared to the values established in 1970. Regarding particulate emissions, the levels are now much lower than those initially set up in 1990.
UNECE has carried out extensive work on technologies reducing harmful effects of diesel internal combustion engines, primarily concerning particulate matter. But good measurement is a precondition for being able to effectively monitor emissions. A group on Particle Measurement Programme was established to develop a new particle number measurement method and to deal with devices required for the measurement of different size particles. The evolution of regulatory instruments on emissions of local pollutants led to limit values for PM emissions of light vehicles that are today more than 30 times lower than 2 decades ago.