Specific air pollutant emissions

Assessment versions

Published (reviewed and quality assured)

• No published assessments

Rationale

Justification for indicator selection

Transport is a major contributor to air pollution. In 2010, road transport alone accounts for 42, 16, 15 and 29 % of total NOx, VOC, PM and CO emissions respectively (see TERM 03 - Transport emissions of air pollutants). Advanced after-treatment technology introduced by the automobile industry due to tighter emission limits can therefore result in considerable reduction in specific pollutant emissions.

The specific emissions of air pollutants of passenger and freight transport are determined by the fleet composition (number and type of vehicles), vehicle utilisation (occupancy rates and load factors) and driving characteristics (speeds, distances). This indicator has been selected to monitor the impact of the stricter emission standards on the specific emissions of air pollutants of the various passenger and freight transport modes.

Scientific references

• No rationale references available

Indicator definition

• Specific emissions are defined as emissions of pollutants per transport unit (passenger-km or tonne-km), specified by mode (road, rail, inland, maritime, air). The pollutants considered include NOx, VOC, PM and CO.
• For passenger transport, specific emissions are expressed in grams of pollutant (NOx, VOC, PM, CO) per passenger-kilometre. For freight transport, specific emissions are expressed in grams of pollutant (NOx, VOC, PM, CO) per tonne-kilometre.

Units

For passenger transport, specific emissions are expressed in grams of pollutant (NOx, VOC, PM, CO) per passenger-kilometer.

For freight transport, specific emissions are expressed in grams of pollutant (NOx, VOC, PM, CO) per tonne-kilometer.

Policy context and targets

Context description

Since specific emissions are expressed per transport unit, occupancy rates and load factors have a considerable effect on specific emissions produced from passenger and freight transport respectively. Reduction of specific emissions can be achieved by increasing occupancy rates and load factors and/or by decreasing the emissions per vehicle-km (e.g. by setting stricter emission standards and introducing more energy efficient technologies such as hybrid, plug-in hybrids, electric vehicles, etc).

Targets

No explicit targets exist at European level directly addressing specific emissions. Policy objectives are rather set with respect to the environmental performance of the fleet (see also TERM 34). 

Related policy documents

No related policy documents have been specified

Methodology

Methodology for indicator calculation

For passenger transport, the specific emissions are calculated by dividing the pollutant emissions of each mode (i.e. road, rail, maritime and air transport) by the respective passenger-kilometres.
For freight transport, the specific emissions are calculated by dividing the pollutant emissions of each mode (i.e. road, rail, inland shipping and maritime transport) by the respective tonne-kilometres.

The pollutant emissions for the remaining modes of transport (i.e. rail, inland shipping, maritime and air transport) are calculated using Tier 1 emission factors from the EMEP/EEA air pollutant emission inventory guidebook.

Activity data for inland shipping rail and maritime transport are extracted from PRIMES, Eurostat.

For air transport, the number of total LTOs (from EUROSTAT-avia_tf_aca) is used to calculate the pollutant emissions.

For the calculation of emissions from electric trains, the relevant emission factor from electricity generation (in grams of pollutant per kWh of energy produced) was used. To this aim, the total emissions of each pollutant (data from the EU submission to CLRTAP), were divided by the total electricity production in the European Union (data from EUROSTAT).

Methodology for gap filling

Passenger- and tonne-kilometres and emissions of NOx, VOC, PM and CO are modelled and therefore no gap filling is necessary. 

Methodology references

• EC4MACS documentation Documents / Methodologies
• EMEP/EEA air pollutant emission inventory guidebook (2013) Technical report No 12/2013

Data specifications

EEA data references

• No datasets have been specified here.

External data references

• EC4MACS model
• Railway transport measurement
• Inland waterways transport
• Railway transport - Total annual passenger transport

Data sources in latest figures

Uncertainties

Methodology uncertainty

COPERT 4 is used for road transport emissions calculations in EC4MACS, whereas the Tier 1 method of the EMEP/EEA air pollutant emission inventory guidebook is used for non-road transport modes.

Data sets uncertainty

Since the data on pollutant emissions, passenger-km and tonne-km are modelled rather than measured, the data must be treated as estimates. The uncertainty of emissions and the uncertainty of passenger-km and tonne-km vary significantly among different countries depending on the underlying statistical data used for each country

Rationale uncertainty

No uncertainty has been specified