Recent Trends And Projections Of Primary No_2 Emissions In Europe

摘要

An assessment of recent trends in primary NO_2 emissions has been carried out for ten case study locations across the European Union. Estimates of the percentage of NO_x from road traffic emitted as primary NO_2 (f-NO_2) have been derived for 1995, 2000 and 2005 by combining the results of a literature survey of primary NO_2 emission factors for different vehicle types and technologies with an emission inventory. Estimates of f-NO_2 have also been derived from ambient monitoring data at roadside sites in each case study location using a model.rnThe results of the analysis of trends show that f-NO_2 has increased in recent years and that the rate of increase has been greatest since 2000. f-NO_2 has increased from 8.6% in 2000 to 12.4% in 2004 as an average across the monitoring sites and from an average of 6.3% in 2000 to 10.6% in 2005 as an average of the emission inventory based calculations for the case study countries. f-NO_2 is predicted to increase further to an average of 19.6% in 2010 and 32.0% in 2020 as a result of the further penetration of exhaust after treatment technologies for diesel vehicles in the fleets. This increase is expected to be offset by the large reduction in NO_x emissions over this period, resulting in an increase in NO_2 emissions from road traffic to 2015, followed by a decline to close to 2004 levels by 2020. Estimates of future ambient NO_2 concentrations have also been calculated for the roadside monitoring sites included in the study. At 29 out of 45 of these sites the annual mean NO_2 limit value is predicted to be exceeded in 2010. At 22 of these sites, the annual mean concentration is expected to remain above the limit value until 2020 and beyond.