This report explains the emission inventories for road transport and other mobile sources, which are part of the annual Danish emission inventories reported to the UNFCCC (United Nations Framework Convention on Climate Change) and the UNECE LRTAP (United Nations Economic Commission for Europe Long Range Transboundary Pollution) conventions. The sub-sectors for other mobile sources are military, railways, navigation, fisheries, civil aviation and non-road machinery in agriculture, forestry, industry and household/gardening.

Table 0 . 1    Mobile sources and CRF codes
Mobile sources	CRF codes
Road transport	1A3b Transport-Road
Military	1A5 Other
Railways	1A3c Railways
Inland waterways	1A3d Transport-Navigation
National sea traffic	1A3d Transport-Navigation
National fishing	1A4c Agriculture/forestry/fisheries
International sea traffic	1A3d Transport-Navigation (international)
Dom. airport traffic  (LTO < 1000 m)	1A3a Transport-Civil aviation
Int. airport traffic  (LTO < 1000 m)	1A3a Transport-Civil aviation (international)
Dom. cruise traffic  (> 1000 m)	1A3a Transport-Civil aviation
Int. cruise traffic  (> 1000 m)	1A3a Transport-Civil aviation (international)
Agriculture	1A4c Agriculture/forestry/fisheries
Forestry	1A4c Agriculture/forestry/fisheries
Industry	1A2f Industry-Other
Household and gardening	1A4b Residential

 

 

 

The emissions of CO₂, CH₄, N₂O, SO₂, NO_X, NMVOC, CO, NH₃, particulate matter (PM), heavy metals, dioxins and PAH are shown in time-series as required by the UNFCCC and the UNECE LRTAP conventions, and grouped according to the UNFCCC Common Reporting Format (CRF) and UNECE National Format for Reporting (NFR) classification codes.

 

Methodologies

 

The emission calculations for road transport are made with an internal NERI model, with a structure similar to the European COPERT III (COmputer Programme to calculate the Emissions from Road Transport) methodology. The new emission factors from the updated COPERT IV version have been implemented in the NERI model. The emissions are calculated for operationally hot engines, during cold start and fuel evaporation. The model also includes the emission effect of catalyst wear. Input data for vehicle stock and mileage is obtained from the Danish Road Directorate, and is grouped according to average fuel consumption and emission behaviour. The emissions are estimated by combining vehicle and annual mileage numbers with hot emission factors, cold:hot ratios and evaporation factors.

 

For air traffic the 2001-2006 estimates are made on a city-pair level, using flight data from the Danish Civil Aviation Agency (CAA-DK) and landing/take off (LTO) and distance related emission factors from the EMEP/CORINAIR guidebook. For previous years the background data consist of LTO/aircraft type statistics from Copenhagen Airport and total LTO numbers from CAA-DK. With appropriate assumptions a consistent time-series of emissions is produced back to 1985 using also the findings from a Danish city-pair emission inventory in 1998.

 

For regional ferries, the fuel consumption and emissions are calculated as a product of number of round trips, sailing time per round trip, engine size, engine load factor and fuel consumption/emission factor. For small ferries and other national sea transport, the calculations are simply fuel based using the fuel consumption findings from a previous Danish research study in combination with average fuel related emission factors.

 

Non-road working machines and equipment, and recreational craft are grouped in the following sectors: Agriculture, Forestry, Industry, Household/Gardening and Inland Waterways. In general the emissions are calculated by combining information on the number of different machine types and their respective load factors, engine sizes, annual working hours and emission factors.

 

For military, railways and fisheries the emissions are calculated as the product of fuel use and emission factors.

 

Fuel sales data are obtained from the Danish energy statistics provided by the Danish Energy Authority (DEA). For road transport and aviation the emission results are adjusted in a fuel balance to ensure that all statistical fuel sold is accounted for in the calculations. For national sea transport, the fuel consumption of heavy oil and gas oil is calculated directly by NERI. Fuel adjustments are made in the fishery sector (gas oil) and stationary industry sources (heavy fuel oil) in order to maintain the grand national energy balance.

 

Emissions from road transport

 

Set in relation to the Danish national emission totals, the largest emission shares for road transport are noted for NO_X, CO, CO₂, NMVOC, TSP, PM_2.5 and PM₁₀. In 2006 the emission percentages were 36, 29, 23, 21, 12, 11 and 8, respectively. The emissions of NH₃, N₂O, CH₄ and SO₂ have marginal shares of 2.2, 1.9, 0.5 and 0.3 %, respectively.

 

From 1990 to 2006 the calculated emission changes for CO₂ (and fuel use), CH₄ and N₂O are 36, -51 and 29 %. For NO_X, NMVOC, CO and particulates (exhaust only: Size is below PM_2.5), the 1985-2006 emission changes are -28, -71, -69, and -30 %.

 

The most significant emission changes from 1985 to 2006 occur for SO₂ and NH₃. For SO₂ the emission drop is 99 % (due to reduced sulphur content in the diesel fuel), whereas the NH₃ emissions increase by 3065 % (due to the introduction of catalyst cars).

Table 0 . 2    Emissions from road transport in 2006, changes from 1985 (19901) to 2006, and 2006 shares of national emission totals
CRF ID	SO2	NOX	NMVOC	CH4	CO
	[tons]	[tons]	[tons]	[tons]	[tons]
Road (1A3b)	79	66993	23171	1290	171521
Total Road non-exhaust
Total Road	79	66993	23171	1290	171521
Total national, 2006	25048	185304	108182	262623	590599
Road- % of national, 2006	0.3	36	21	0.5	29
Road- % change 1985-2006	-99	-28	-71	-511	-69
CRF ID	CO2	N2O	NH3	TSP	PM10	PM2.5
	[ktons]	[tons]	[tons]	[tons]	[tons]	[tons]
Road (1A3b)	12594	402	1951	3101	3101	3101
Total Road non-exhaust				2663	1726	937
Total Road	12594	402	1951	5764	4828	4039
Total national, 2006	55749	21026	89530	25048	38460	27726
Road- % of national, 2006	23	1.9	2.2	12	8.1	11
Road- % change 1985-2006	361	291	3065	-302	-302	-302

 

 

 

Road transport exhaust PM emissions almost solely come from diesel fuelled vehicles. The largest source is light duty trucks followed by heavy-duty vehicles and passenger cars in decreasing order. Since the mid-1990s the emissions from light and heavy duty vehicles have decreased significantly due to gradually stricter Euro emission standards. For diesel passenger cars, the environmental benefit of introducing new engines with lower particulate emissions since 1990 is more or less compensated by an increase in vehicle new sales in the later years.

 

The trend in non-exhaust PM follows the traffic growth in general, and in 2006 the TSP (total particulate matter), PM₁₀ and PM_2.5 shares were 46, 36 and 23 % of the respective road traffic totals. The non-exhaust PM is gaining more relative importance, in pace with the year by year reductions of exhaust PM.

 

Historically the emission totals of NO_X and especially NMVOC and CO have been dominated by the contributions coming from gasoline passenger cars. However, the emissions from this vehicle type have been reduced since the introduction of catalyst cars in 1990. A negative side effect of this technology though is the increase in N₂O and NH₃ emissions. The NO_X, NMVOC and CO emissions reductions are fortified by the introduction of new gradually stricter Euro emission standards for all other vehicle classes.

 

Emissions from other mobile sources

 

For other mobile sources the emissions of NO_X, CO, NMVOC, TSP and PM_2.5 have the largest shares of the national totals in 2006. The shares are 23, 21, 13, 10 and 9 %, respectively. The 2006 CO₂, SO₂ and PM₁₀ emission shares are 7 %, whereas the emissions of N₂O, NH₃ and CH₄ have marginal shares of 1 % or less in 2006.

 

From 1990 to 2006 the calculated emission changes for CO₂ (and fuel use), CH₄ and N₂O are -10, 5 and -11 %. The emissions of SO₂, particulates (all size fractions), NO_X, NMVOC and CO have decreased by 88, 56, 14, 12 and 9 % from 1985 to 2006. For NH₃ the emissions have increased by 8 % in the same time period.

Table 0 . 3     Emissions from other mobile sources in 2006, changes from 1985 (19903) to 2006, and 2006 shares of national emission totals
CRF ID	SO2	NOX	NMVOC	CH4	CO
	[tons]	[tons]	[tons]	[tons]	[tons]
Industry-Other (1A2f)	30	10807	1583	44	7515
Civil Aviation (1A3a)	45	596	155	6	838
Railways (1A3c)	1	3542	230	9	626
Navigation (1A3d)	1089	7436	1195	32	7192
Residential (1A4b)	1	275	8037	233	87744
Ag./for./fish. (1A4c)	632	20199	2541	94	16976
Military (1A5)	26	619	56	6	391
Total other mobile	1824	43475	13796	425	121282
Total national, 2006	25048	185304	108182	262623	590599
Other mobile- % of national, 2006	7.3	23	13	0.2	21
Other mobile - % change 1985-2006	-88	-14	-12	53	-9
CRF ID	CO2	N2O	NH3	TSP	PM10	PM2.5
	[ktons]	[tons]	[tons]	[tons]	[tons]	[tons]
Industry-Other (1A2f)	1021	43	2	991	991	991
Civil Aviation (1A3a)	141	8	0	3	3	3
Railways (1A3c)	227	6	1	120	120	120
Navigation (1A3d)	455	26	0	291	289	288
Residential (1A4b)	233	4	0	79	79	79
Ag./for./fish. (1A4c)	1599	77	3	1086	1084	1084
Military (1A5)	126	4	0	21	21	21
Total other mobile	3802	168	7	2590	2587	2585
Total national, 2006	55749	21026	89530	25048	38460	27726
Other mobile- % of national, 2006	6.8	0.8	0.0	10	6.7	9.3
Other mobile - % change 1985-2006	-103	-113	8	-56	-56	-56

 

 

 

The largest source of NO_X and particulate emissions are agriculture/forestry/fisheries, followed by industry and navigation. For NMVOC and CO most of the emissions come from gasoline fuelled working machinery in the residential sector.

 

Heavy metals

 

For heavy metals the development in emissions follows the fuel use trends. The road transport shares for copper (Cu), zinc (Zn), chromium (Cr) and cadmium (Cd) are 71, 15, 15 and 6 % of national totals in 2006, and for other mobile sources the lead (Pb), Cu and nickel (Ni) shares are 21, 17 and 5 %. For the remaining components, the emission shares are less than 5 %.

 

The road transport emissions have increased by 36 % from 1990 to 2006. For Pb though there has been an almost 100 % emission decline, due to the phasing out of leaded gasoline fuels until 1994. For other mobile sources the emissions of Cd, Zn and Cu have emission decreases of 20 % or less in the same time period. The emissions of Pb, Ni, arsenic (Ar), selenium (Se), mercury (Hg) and Cr decrease even further. The respective emission declines are 79, 81, 68, 40, 26 and 23 %. For Ni, Se, Ar and Hg the emission decreases are due to a reduction in residual oil fuel use, and for Pb the reason for the emission drop is the contemporary phasing out of gasoline fuelled tractors and lead in gasoline fuel.

 

PAH’s

 

The PAH emission shares for road transport and other mobile sources are 5 % or less of the national total in 2006.

 

Uncertainties

 

For mobile sources in 2006 the CO₂ emissions are determined with the highest accuracy, followed by the CH₄, TSP, PM₁₀, SO₂, NMVOC, NO_X, PM_2.5, CO and N₂O emissions with increasing levels of uncertainties. The uncertainties are 4, 34, 47, 48, 49, 49, 50, 50, 51 and 136 %, respectively. The uncertainties for the 1990-2006 emission trends are 4, 6, 8, 4, 10, 7, 7, 12 and 62 % for the emissions in the same consecutive order. For NH₃, heavy metals and POPs the 2006 emissions have uncertainty levels of between 700 and 1000 %. In this case the emission trend uncertainties are significantly lower; still large fluctuations exist between the calculated values for the different emission components.

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