Factorization of air pollutant emissions: projections versus observed trends in Europe

This paper revisits the emission scenarios of the European Commission's 2005 Thematic Strategy on Air Pollution
(TSAP) in light of today's knowledge. We review assumptions made in the past on the main drivers of emission
changes, i.e., demographic trends, economic growth, changes in the energy intensity of GDP, fuel-switching, and
application of dedicatedemission controlmeasures. Our analysis shows that formost of these drivers, actual trends
have not matched initial expectations. Observed ammonia and sulfur emissions in European Union in 2010 were
10% to 20% lower than projected,while emissions of nitrogen oxides and particulatematter exceeded estimates by
8% to 15%. In general, a higher efficiency of dedicated emission controls compensated for a lower-than-expected
decline in total energy consumption as well as a delay in the phase-out of coal. For 2020, updated projections anticipate
lower sulfur and nitrogen oxide emissions than those under the 2005 baseline, whereby the degree to
which these emissions are lower depends on what assumptions are made for emission controls and new vehicle
standards. Projected levels of particulates are about 10% higher, while smaller differences emerge for other pollutants.
New emission projections suggest that environmental targets established by the TSAP for the protection of
human health, eutrophication and forest acidification will not be met without additional measures.