Scottish Transport Statistics No 34 2015 Edition

Environment and Emissions

1 Introduction

1.1 This chapter provides information about the impact of transport on certain aspects of the environment with a focus on greenhouse gas emissions and air quality. Statistics include atmospheric pollutants and emissions of greenhouse gases by types of transport as well as details of emissions levels of road vehicles. Data from other chapters within Scottish Transport Statistics are referred to in the analysis.

Key points

• Transport accounts for just under a quarter of Scotland's greenhouse gas emissions under the definition set out in the Climate Change Scotland Act.
• Road transport makes up 72% of transport emissions.
• Through September of the current year (2015) there were 1,050 Ultra Low Emission Vehicles registered in Scotland for the first time – 70% up on the corresponding period in 2014.
• In 2013 transport accounted for 40% of emissions of oxides of nitrogen and 17% of particulate matter (PM10). As at 15 October 2015, there were 31 active Air Quality Management Areas related to these pollutants.

2 Main Points

Air pollutant emissions

2.1 The main pollutants of current concern in Scotland are:

• Oxides of nitrogen (NOx);
• Particulate matter (PM10 and PM2.5);
• Sulphur dioxide (SO2);
• Non-methane volatile organic compounds (NMVOCs);
• Ground-level ozone (O3); and
• Ammonia (NH3).

2.2 Of these, transport is a significant contributor to emissions of oxides of nitrogen and particulate matter. Transport is also linked to ground level ozone, which is a secondary pollutant produced by chemical reactions involving oxides of nitrogen.

2.3 Historically, transport was also a major contributor to emissions of lead and non-methane volatile organic compounds (NMVOCs). The significant decline in lead emissions (99% since 1990) has been mainly driven by the progressive phasing out of leaded petrol. The lead content of petrol was reduced from around 0.34 g/l to 0.143 g/l in 1986. From 1987, sales of unleaded petrol increased, particularly as a result of the increased use of cars fitted with three-way catalysts. Leaded petrol was phased out from general sale at the end of 1999. For NMVOCs, transport sector emissions declined significantly during the 1990s due to the increased use of catalytic converters and fuel switching from petrol to diesel cars. (Chart 13.a)

2.4 Emissions of nitrogen oxides were estimated to be 94kt in 2013 of which transport accounted for 40%. Since 1990, transport emissions have declined by 69%. Transport emissions have declined due to a number of reasons including the requirement for new petrol cars to be fitted with three-way catalysts since 1989 and, in more recent years, "Euro standards" for new cars have driven a reduction in emissions, although studies show that the diesel Euro 5 cars have not performed as well as expected. Since 2008, there has been a general reduction in the emissions from passenger cars, mainly driven by improvement in catalyst repair rates. (Table 13.a)

2.5 Emissions of PM10 were estimated to be 14kt in 2013, of which transport accounted for 17%. Since 1990, transport emissions have declined by 43%. For particulate matter, the main source of road transport emissions is exhaust gases from diesel engines. Emissions from diesel vehicles have been growing due to the growth in heavy-duty vehicle traffic and the move towards more diesel cars. Since around 1992, however, emissions from diesel vehicles have been decreasing due to the penetration of new vehicles meeting tighter PM10 emission regulations ("Euro standards" for diesel vehicles were first introduced in 1992), while non-exhaust emissions from tyre and brake wear and road abrasion are increasingly more important. (Table 13.a)

Air quality

2.6 Concentrations of air pollutants are sampled at automatic monitoring sites and the information is held in the "Scottish Air Quality Database" on the "Air Quality in Scotland" website (http://www.scottishairquality.co.uk/) and also in summary form in the Scottish Government database "Scottish Environment Statistics Online" (http://www.gov.scot/seso/Datasets.aspx?TID=2). The data section of the "Air Quality in Scotland" website provides detailed information on all sites while the publication section of the website includes reports showing trends. Table 13.b in this publication shows concentrations of nitrogen dioxide, ozone and PM10 at a mixture of urban and rural monitoring sites with long time series. Air quality is monitored against standards set as air quality objectives (see Notes and Definitions section, page 225).

Nitrogen dioxide (NO2)

2.7 For some of the selected monitoring sites, nitrogen dioxide concentrations show a downward trend. In 2014, 8 of the 15 sites selected that recorded nitrogen dioxide concentrations with a data capture rate of over 75% had the lowest concentrations recorded over the period 2003-2014. In 2010, concentrations at nine of the selected sites were higher than in the previous year and all subsequent years. In 2014, 68 sites in Scotland recorded nitrogen dioxide concentrations with a data capture rate of over 75%, of which 55 were roadside or kerbside locations. Of these 68 sites, 10 had concentrations in excess of the air quality strategy objective of 40 g/m3 as an annual mean. All 10 sites were located at the roadside or kerbside. (Table 13.b)

Ozone (O3)

2.8 Though transport emissions contribute to ozone formation, levels of ozone are generally higher in rural areas due to the long-range transportation of primary pollutants from urban sources. In addition, ozone reacts with nitric oxide, which is more abundant in urban areas due to traffic emissions, to form nitrogen dioxide; therefore ozone levels are usually lower in urban areas. While at the selected monitoring sites there is some indication of a downward trend in the number of occurrences of maximum daily concentrations exceeding 100 g/m3, there is no trend in average annual concentrations. In 2014, of the 9 sites in Scotland recording ozone with a data capture rate of over 75%, 1 site (Strath Vaich) had more than 10 occurrences of maximum daily concentrations exceeding 100 g/m3. (Table 13.b)

Particulate matter (PM10)

2.9 PM10 concentrations show a general downward trend at the selected sites. In 2014, of the 58 sites in Scotland recording PM10 with a data capture rate over 75%, 10 (all kerbside or roadside) had concentrations greater than the air quality objective of 18 g/m3 as an annual mean. One of these sites (Aberdeen Market Street 2) also exceeded the air quality objective set as 7 occurrences of a daily mean above 50 g/m3. (Table 13.b)

Air Quality Management Areas

2.10 Whenever it appears that one or more of the air quality objectives is unlikely to be met by the required date, the local authority concerned must declare an Air Quality Management Area (AQMA) covering the area of concern. The authority must then prepare and implement an action plan outlining how it intends to tackle the issues identified. Table 13.c summarises active AQMAs and the pollutants of concern. As at 15 October 2015, there were 32 active AQMAs, all but one of which related to either NO2 or PM10, or both.

Greenhouse gases

2.11 In 2013, Transport (including international aviation and shipping) accounted for 12.9 million tonnes of carbon dioxide equivalent (MtCO2e). This represents 24.4 per cent of net greenhouse gas emissions allocated to Scotland in the Greenhouse Gas Inventories, up from 23.7 per cent in 2012. Total net emissions from all sources fell by 3.6 per cent between 2012 and 2013, before making an adjustment to account for the EU Emissions Trading System while in transport emissions fell by 0.6 per cent. Within Transport's emissions, Road Transportation accounted for approximately 72 per cent of the transport total, (Passenger Cars contribute 39 per cent alone). Heavy Goods Vehicles and Light Goods Vehicles were the other significant contributors to road emissions (24 per cent and 15 per cent respectively). International Aviation and Shipping contributed roughly 19 per cent and Domestic Aviation 5 per cent of transport's total emissions. The contribution from rail, 1.3 per cent, was roughly half the contribution of domestic maritime, 2.4 per cent. It should be noted that these estimates use a methodology designed to produce internationally-comparable figures so apparent year-to-year fluctuations could be due in part to limitations in or changes to the underlying data or calculations. See Table 13.2 for more detail and emissions from earlier years and Section 4.2 below for more detail on the methodology used.

2.12 Figure 13.2 shows transport emissions over time, by mode. Estimated car emissions have fallen by 15 per cent since 2003. Traffic levels have remained relatively stable over the last few years so the reduction in emissions seen will be due to the introduction of more fuel efficient vehicles as well as other more fuel efficient driving, particularly in the business fleet. More detail on car emissions is set out from paragraph 2.7 of this chapter while more details on traffic volumes by mode can be found in chapter 5 of STS. Details of personal modal choice can be found in chapter 11.

2.13 The Greenhouse Gas Inventories report the emissions of the six gases that are listed under the Kyoto Protocol. In the case of transport, the quantities of gases involved are relatively small except for carbon dioxide, which accounts for about 99 per cent of transport's total. (Table 13.3).

2.14 Table 13.4 presents some comparisons between the UK as a whole and Scotland. Overall, Scotland's emissions account for 8.2 per cent of UK transport emissions. At 8.7 per cent, Scottish road emissions are marginally above a proportionate share of the UK total while bus, 12.5 per cent, and domestic aviation 19.8 per cent, are significantly above that benchmark At 5.2 per cent, Scotland's total aviation emissions sit well below a proportionate share.

2.15 Estimates of carbon dioxide emissions per passenger-km for different modes of transport are available only for GB/UK as a whole. The lowest emitting modes of transport per passenger-km are national coaches and national rail - 29 and 45 grams of CO2e respectively. Air travel tends to be the highest emitter per passenger-kilometre, particularly domestic flights, which account for 158 grams of CO2e per passenger kilometre (Table 13.5). The basis of these estimates is described in section 13.5 page 300.

Car emissions

2.16 Newly registered cars are becoming more fuel efficient and thus emit fewer emissions per kilometre. Figure 13.3 shows the steady downward trend in average CO2 emissions for newly registered cars in Scotland. Average CO2 emissions in Scotland for new car registrations has fallen by 25 per cent over the last ten years and by 3.1 per cent in the last year. (Table 13.6)

2.17 More detail of this trend is shown in figure 13.4. The proportion of newly registered cars with emissions of 140g/km or lower has increased from 17 per cent in 2003 to 81 per cent in 2013. Cars with emissions of over 200g/km have decreased from 15 per cent of new cars to under 1 per cent. These changes are at least in part the result of changes to vehicle excise duty bandings made by the UK Government in recent years.

Ultra low emission vehicles (ULEV)

2.18 The number of ultra-low emission vehicles registered in Scotland so far in 2015 is 70% up on the corresponding figure in 2014 (January – September). Almost all of these sales have been supported by Plug-in-Grant scheme for cars and vans. At the end of Q3 2015 there are almost 2,800 ULEVs registered in Scotland (Table 13.7 and 13.8)

Registrations by type of vehicle

2.19 The overwhelming majority (99.4 per cent) of vehicles licensed for use on the roads in Scotland are though still powered by either petrol or diesel. Historically petrol powered vehicles have been outsold by diesel vehicles but overall there are more petrol vehicles on the road than diesel ones. While 30 per cent of all diesel vehicles are body types other than cars only 5 per cent of petrol vehicles were not cars. (Table 13.9 and 13.10)

Table 13.1a Emissions of air pollutants by type of transport allocated to Scotland¹

	1990	1995	2003	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013
													thousand tonnes of pollutant
Oxides of nitrogen (NOx)
Road transport	105.2	82.9	49.2	47.3	45.6	45.0	43.6	41.1	33.4	31.9	30.1	28.9	27.9
Buses and coaches	6.4	6.2	5.4	4.8	4.7	4.7	4.7	4.3	4.1	4.1	3.6	3.3	3.1
Passenger cars	70.3	51.1	22.6	21.3	20.1	19.6	18.0	17.5	13.1	12.4	12.3	12.4	12.5
HGVs	19.3	17.2	14.8	14.9	14.7	14.7	14.9	13.6	10.8	10.1	8.9	7.9	6.7
Light goods vehicles	9.1	8.3	6.3	6.2	6.0	5.9	5.9	5.6	5.3	5.3	5.3	5.3	5.5
Mopeds and motorcycles	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1
Railways	2.1	2.2	2.7	2.8	2.9	2.8	2.8	2.8	2.9	2.9	3.0	2.8	2.5
Aviation	0.7	0.7	1.0	1.0	1.1	1.1	1.1	1.0	0.9	0.9	0.9	0.8	0.9
Shipping	9.6	10.2	8.1	7.9	7.8	7.1	7.1	7.0	6.4	6.2	5.4	5.2	4.5
Other transport	4.2	3.5	2.8	2.9	2.7	2.8	3.0	2.8	2.7	2.6	2.4	2.2	2.0
Total Transport	121.7	99.5	63.7	61.8	60.1	58.8	57.6	54.8	46.4	44.4	41.8	39.9	37.8
Non-transport emissions	161.3	122.1	90.0	87.3	86.9	96.5	87.5	75.7	66.7	68.6	58.0	58.2	56.0
Emissions from all sources	283.1	221.6	153.7	149.1	147.0	155.3	145.2	130.5	113.1	113.0	99.8	98.1	93.8
Transport % of all NOx emissions	43%	45%	41%	41%	41%	38%	40%	42%	41%	39%	42%	41%	40%
Particulate matter (PM10)
Road transport2	3.00	3.44	2.67	2.62	2.55	2.52	2.47	2.37	2.26	2.19	2.03	1.95	1.86
Buses and coaches	0.34	0.33	0.18	0.15	0.14	0.14	0.14	0.13	0.12	0.12	0.10	0.10	0.10
Passenger cars	1.11	1.40	1.23	1.22	1.21	1.23	1.21	1.22	1.21	1.16	1.09	1.08	1.04
HGVs	0.94	0.85	0.57	0.56	0.55	0.54	0.52	0.47	0.41	0.39	0.36	0.34	0.32
Light goods vehicles	0.59	0.86	0.69	0.67	0.64	0.60	0.58	0.55	0.52	0.52	0.47	0.44	0.40
Mopeds and motorcycles	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01
Railways	0.09	0.10	0.10	0.10	0.10	0.11	0.10	0.11	0.11	0.11	0.11	0.11	0.10
Aviation3	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01
Shipping4	0.78	0.73	0.55	0.54	0.54	0.49	0.35	0.33	0.31	0.30	0.27	0.26	0.23
Other transport5	0.15	0.13	0.13	0.13	0.12	0.13	0.13	0.12	0.11	0.11	0.10	0.09	0.08
Total Transport	4.03	4.42	3.46	3.40	3.33	3.26	3.06	2.94	2.80	2.71	2.52	2.41	2.28
Non-transport emissions	24.61	17.45	11.27	11.81	11.37	12.62	12.44	11.45	10.55	11.94	11.13	10.83	11.31
Emissions from all sources	28.64	21.87	14.74	15.21	14.70	15.88	15.50	14.39	13.35	14.65	13.65	13.24	13.59
Transport % of all PM10 emissions	14%	20%	24%	22%	23%	21%	20%	20%	21%	19%	18%	18%	17%

Source: National Atmoshpheric Emissions Inventory - Not National Statistics

1. From the Air Quality Pollutant Inventories for England, Scotland, Wales and Northern Ireland: 1990 - 2012.
Emissions are available annually only with effect from 1998. All the figures in this table are updated annually to reflect changes to the methodology used.

2. The Road Transport emissions database uses emission factors (g/km) for different types of vehicles, which depend on the fuel type (petrol or diesel) and are influenced by the drive cycle or average speeds on the different types of roads; traffic activity for each DA region, including distance and average speed travelled by each type of vehicle on each type of road; DA-specific fleet data on petrol/diesel car mix, car engine size and fleet composition (including age).
The sum of emissions across all parts of the UK equates to the total for the UK inventory where that total is normalised using fuel sales data of petrol and DERV.

3. Only take-off and landing emissions are reported.

4. Includes emissions from coastal shipping, shipping betweeen Scotland and the Overseas Territories, fishing vessels, marine engines, personal watercraft, inland goods-carrying vehicles, motorboats and sail boats with auxiliary engines.

5. Includes military aviation and naval vessels, aircraft support vehicles and railways stationary combustion.

Table 13.1b Atmospheric concentrations of selected pollutants (*, a) recorded at Air Quality Monitoring Stations

Air Quality  monitoring station 1	Type of monitoring station	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013	2014
Nitrogen dioxide 2												micrograms per cubic metre
Aberdeen Errol Place	Urban background	26	24	27	24	25	26	*	23	21	*	22
Aberdeen Union Street	Roadside	..	64	49	53	55	*	59	44	53	48	47
Bishopbriggs, Kirkintilloch Road	Roadside	35	*	33	32	33	33	33	*	30	31	29
Dumfries, A780	Roadside	37	36	37	38	37	35	40	32	33	30	30
Dundee Lochee Road	Roadside	..	..	*	53	53	54	55	*	53	52	46
Dundee Union Street	Kerbside	..	..	*	36	43	45	40	36	32	31	29
Eskdalemuir	Rural	..	4	4	5	5	4	3	3	3	3	2
Edinburgh Gorgie Road	Roadside	..	34	..	41	42	38	41	37	39	38	34
Edinburgh St Leonards	Urban background	25	25	27	27	31	24	31	25	24	22	*
Glasgow Centre, St Enoch's Square	Urban centre	36	33	31	31	35	42	44	34	*	..	..
Glasgow Kerbside, Hope Street	Kerbside	68	62	68	70	82	78	84	72	72	67	68
Glasgow Byres Road	Roadside	..	38	41	40	43	40	47	*	39	44	*
Glasgow City Chambers	Urban background	49	46	47	47	48	46	49	*	..	..	..
Inverness, Telford Street	Roadside	23	21	21	22	21	21	24	27	29	21	21
Perth High Street	Roadside	28	28	28	29	27	25	30	27	26	22	22
Ozone 3												micrograms per cubic metre
Edinburgh St Leonards	Urban background	53	53	52	48	49	52	33	40	49	49	*
Eskdalemuir	Rural	53	51	58	54	57	56	55	53	51	60	58
Strath Vaich	Rural	76	67	72	68	73	67	61	64	67	70	69
												Number of daily maximums (measured as an 8-hour running mean) exceeding 100ug/m3
Edinburgh St Leonards	Urban background	12	13	16	9	14	3	0	0	4	2	*
Eskdalemuir	Rural	5	1	23	11	16	20	2	10	7	14	7
Strath Vaich	Rural	29	18	47	17	65	4	4	14	12	23	17
Particulates (PM10) 4												micrograms per cubic metre
Aberdeen Errol Place	Urban background	19	19	20	17	16	15	13	14	12	13	15
Aberdeen Union Street	Roadside	..	25	26	19	22	18	18	22	21	20	18
Bishopbriggs, Kirkintilloch Road	Roadside	..	25	22	22	17	19	19	17	15	*	*
Dundee Broughty Ferry	Roadside	..	..	20	18	15	15	16	16	14	16	15
Dundee Union Street	Kerbside	..	..	24	22	17	17	17	19	16	15	16
Edinburgh Queen Street	Roadside	..	..	..	26	18	17	18	16	16	17	17
Edinburgh St Leonards	Urban background	19	18	20	19	15	*	14	15	*	14	*
Glasgow Byres Road	Roadside	..	27	27	25	10	19	23	*	13	*	*
Glasgow Waulkmillglen Reservoir	Rural	..	14	15	15	12	11	12	12	11	12	*
Glasgow Kerbside, Hope Street	Kerbside	27	29	38	32	27	26	29	*	*	23	*
Glasgow Centre, St Enoch's Square	Urban centre	*	20	21	20	19	25	*	17	*	..	..
Inverness, Telford Street	Roadside	14	15	16	14	12	12	14	12	11	12	11
Perth High Street	Roadside	17	19	21	20	16	16	19	19	15	16	14

Source: Scottish Government - Not National Statistics

1.  The sites chosen are a mixture of urban and rural site types with long time series
2.  Annual mean concentration of atmospheric nitrogen dioxide.
3.  Annual mean ground level ozone concentration.
4.  Annual mean atmospheric PM₁₀ concentration.

(*) Since 2003, results where data capture is less than 75% are not shown.
(..) Site not in operation for given year
(a) those to which transport is understood to contribute significantly -  see text.

Table 13.1c Number of active Air Quality Management Areas by pollutant and local authority, as at 15 October 2015

Local authority	Pollutant(s)				All pollutants
	Nitrogen dioxide (NO2) only	Particulate Matter (PM10) only	Both NO2 and PM10	Sulphur dioxide
Aberdeen City Council	-	-	3	-	3
City of Edinburgh Council	5	-	-	-	5
Dundee City Council	-	-	1	-	1
East Dunbartonshire Council	-	-	2	-	2
East Lothian Council	1	-	-	-	1
Falkirk Council	1	1	1	1	4
Fife Council	1	-	1	-	2
Glasgow City Council	2	-	1	-	3
Highland Council	1	-	-	-	1
North Lanarkshire Council	-	5	-	-	5
Perth & Kinross Council	-	-	2	-	2
Renfrewshire Council	-	-	1	-	1
South Lanarkshire Council	-	1	-	-	1
West Lothian Council	-	-	1	-	1
Scotland	11	7	13	1	32

Source: Scottish Air Quality website - Not National Statistics

Figure 13.1 Index of air pollutant emissions from transport in Scotland, 1990-2013 (1990=100)

Table 13.2 Emissions of greenhouse gases by type of transport allocated to Scotland ¹

	1990	1995	2003	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013
													thousand tonnes of carbon dioxide equivalent
Transport
Road transportation 2	9,084	9,149	9,674	9,761	9,859	10,043	10,221	9,840	9,525	9,431	9,275	9,355	9,311
Buses & coaches	383	393	518	493	506	520	560	543	545	554	519	487	505
Passenger cars	5,775	5,744	5,969	6,002	5,957	5,974	5,942	5,797	5,567	5,303	5,190	5,161	5,062
Heavy Goods Vehicles	2,085	2,085	1,905	1,940	2,040	2,135	2,235	2,043	1,999	2,149	2,133	2,254	2,256
Light Goods Vehicles	795	890	1,196	1,238	1,270	1,325	1,394	1,369	1,332	1,345	1,358	1,378	1,416
Mopeds & motorcycles	31	22	39	37	38	36	39	38	38	34	34	33	33
Other road3	15	15	47	50	48	53	51	50	44	46	42	42	39
Railways	124	125	149	154	154	158	169	170	169	169	167	171	167
Aviation and Maritime	3,996	3,931	3,582	3,854	4,094	4,475	4,445	4,485	4,165	3,710	3,745	3,490	3,455
International Aviation & international shipping 4	2,566	2,597	2,163	2,420	2,611	2,993	2,966	3,079	2,893	2,519	2,611	2,397	2,403
Domestic Aviation	806	696	862	872	921	949	943	868	765	702	685	658	648
Domestic Shipping and Maritime	575	586	484	483	477	445	446	451	425	410	366	350	315
Other aviation and maritime5	49	51	74	80	85	88	90	87	82	79	82	85	88
Total transport	13,203	13,205	13,406	13,770	14,106	14,676	14,835	14,495	13,859	13,311	13,187	13,016	12,932
Non-transport net emissions	67,468	67,954	58,866	56,108	54,322	56,757	51,784	49,796	45,926	48,200	41,656	41,924	40,030
Net emissions all sources 6	80,671	81,159	72,272	69,878	68,428	71,433	66,618	64,290	59,784	61,511	54,843	54,940	52,961
Transport % of
Total net emissions 3	16.4	16.3	18.5	19.7	20.6	20.5	22.3	22.5	23.2	21.6	24.0	23.7	24.4

Source: Greenhouse Gas Inventories for England, Scotland, Wales and Northern Ireland (see sources section for more details) - Not National Statistics

1. From the Greenhouse Gas Inventories for England, Scotland, Wales and Northern Ireland: 1990 - 2013. Some headings below are own aggregations
Emissions estimates are available for 1990, 1995 and then annually from 1998. All the figures in this table reflect the current methodology used in the calculation of emissions within the National Atmospheric Emissions Inventory.
2. The method used to estimate carbon dioxide (CO2) emissions from road transport is based on vehicle kilometre travelled data constrained so that the sum of emissions across all parts of the UK equates to the total for the UK inventory, where that total is derived from fuel sales data of petrol and DERV within the UK as specified in the reporting guidelines of the Intergovernmental Panel on Climate Change. Further detail can be found in Section 3.3 of the report and in Annex 2.
3. Other road includes urea used as part of an addative for certain categories of diesel engine, LPG use and road vehicle engines.
4. A split between International aviation and international shipping can be found in the Carbon Accout for Transport
5. Aviation support vehicles at airports
6. Net emissions take account of removals of carbon dioxide due to carbon sinks.

Table 13.3   Emissions of greenhouse gases1 by Transport 2 allocated to Scotland

	1990	1995	2003	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013
										thousand tonnes of carbon dioxide equivalent
Greenhouse gases - excluding international aviation and shipping
Carbon dioxide	10,466	10,412	11,112	11,225	11,375	11,566	11,755	11,316	10,875	10,701	10,483	10,522	10,428
Methane	59	44	19	17	16	15	13	12	8	7	6	6	5
Nitrous Oxide	113	152	112	108	104	102	100	88	82	83	86	91	96
All greenhouse gases - excluding international aviation and shipping	10,637	10,608	11,243	11,349	11,495	11,683	11,869	11,415	10,966	10,791	10,576	10,619	10,529
Greenhouse gases - international aviation and shipping
Carbon dioxide	2,544	2,575	2,144	2,399	2,589	2,968	2,941	3,053	2,868	2,498	2,589	2,376	2,382
Methane	2	1	1	1	1	1	1	1	1	1	1	1	1
Nitrous Oxide	20	21	18	20	22	25	24	25	23	21	21	20	20
All greenhouse gases - international aviation and shipping	2,566	2,597	2,163	2,420	2,611	2,993	2,966	3,079	2,893	2,519	2,611	2,397	2,403
All transport greenhouse gases	13,203	13,205	13,406	13,770	14,106	14,676	14,835	14,495	13,859	13,311	13,187	13,016	12,932

Source: Greenhouse Gas Inventories for England, Scotland, Wales and Northern Ireland (see sources section for more details) - Not National Statistics

1.  The footnotes to Table 5.12 also apply to this table, including revision of the figures; though note that emisions of methane and nitrous oxide from road transport are estimated using vehicle kilometre data in both of the calculation methods, and the total emissions of these GHGs from the two methods are identical. There are no emissions of other greenhouse gases by Transport in the Inventory.
2.  The figures for greenhouse gas emissions are expressed in terms of their Global Warming Potential in tonnes of carbon dioxide equivalent. To convert from tonnes of carbon dioxide equivalent to tonnes of other gases multiply by the following factors: 
GWP methane - 25, GWP nitrous oxide - 298.

Table 13.4 Comparison of transport greenhouse gas emissions Scotland and UK as a whole

	Scottish emissions 2013	Scottish emissions as a % of UK emissions 2013	Change in Scottish emissions (2012-2013)	Change in UK emissions (2012-2013)	Change in Scottish emissions (1990-2013)	Change in UK emissions (1990-2013)
All Transport	12,932	8.2%	-0.6%	-1.0%	-2.1%	7.8%
All Transport  (excl. International Aviation and Shipping)	10,529	9.1%	-0.8%	-1.0%	-1.0%	-4.1%
Road Transport1,2	9,311	8.7%	-0.5%	-0.8%	2.5%	-2.1%
of which:
Cars	5,062	8.1%	-1.9%	-2.1%	-12.4%	-13.5%
Heavy Goods Vehicles	2,256	9.3%	0.1%	0.2%	8.2%	1.3%
Light Goods Vehicles	1,416	9.0%	2.8%	2.7%	78.1%	66.8%
Buses & coaches	505	12.5%	3.5%	2.5%	31.9%	19.5%
Motorcycles	33	6.4%	-0.9%	-4.5%	-12.4%	-18.0%
Rural	4,627	10.9%	0.0%	-0.4%	-3.8%	-3.5%
Urban	2,732	7.3%	-1.9%	-2.1%	-9.9%	-15.1%
Motorway	1,897	7.1%	0.6%	0.6%	56.5%	26.6%
Rail	166	7.8%	-2.6%	-2.9%	34.8%	0.8%
Aviation (Domestic)	648	19.8%	-1.5%	-4.8%	-19.5%	-39.6%
Aviation (Including International)	1,862	5.2%	2.0%	-1.0%	33.4%	69.9%
Maritime (Domestic)	315	10.8%	-10.0%	-5.4%	-45.2%	-20.4%
Maritime (Including International)	1,592	14.1%	-4.3%	-3.4%	-38.7%	-8.8%

Source: Carbon Account for Transport (see sources section for more details) - Not National Statistics

1. Road transport excludes the 'other' category shown in Table 13.2
2. The comparisions shown by category of road excludes emissions from the 'other' category of road transport and emissions generated from cold starts

Figure 13.2: Greenhouse gas emissions attributed to Scotland by mode of transport

Table 13.5 UK Carbon Dioxide emissions: grams per passenger-kilometre, 2015 ¹

	grams of CO2 per pass-km
Petrol cars	127
Diesel cars	121
Average petrol hybrid	85
All Cars (average)	124
Petrol motorbike	120
Bus	109
Coach	29
National rail	45
Light rail and tram	55
Ferry	116
Domestic flights 3	158
Short haul international 3	90
Long haul international 3	105

Source: DEFRA - Not National Statistics

1. Source: http://www.ukconversionfactorscarbonsmart.co.uk/ All figures are estimated using data for GB/UK as a whole so do not specifically relate to Scotland.
2. All Car figures assume an average car occupancy rate of 1.51 passengers based on the latest Scottish Household Survey Travel Diary: 2011
3. The long haul estimate is based on a flight length from the Guidelines of of 6482 km, short haul 1108km and domestic 463km.
4. All the factors include the distance uplift of 8% to compensate for planes not flying using the most direct route i.e. flying around international airspace, stacking etc.

Table 13.6:  Cars registered for the first time by CO2 emission band, Scotland

	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013	2014
										thousands
Up to 100 g/km	-	0.0	-	0.0	0.3	1.3	2.3	4.6	13.0	25.6	36.2
101 - 110 g/km	0.7	1.2	3.4	4.0	4.8	8.1	9.2	15.3	17.3	23.5	34.8
111 - 120 g/km	7.6	5.7	5.4	6.4	12.1	24.7	29.7	28.1	31.6	43.1	48.2
121 - 130 g/km	7.3	9.3	10.1	9.4	11.0	15.4	27.6	28.5	39.4	39.7	36.5
131 - 140 g/km	25.4	23.6	25.2	38.2	36.7	41.5	33.9	31.4	30.5	26.3	23.8
141 - 150 g/km	42.2	35.5	31.4	27.5	24.3	24.7	20.5	20.3	18.9	17.0	13.8
151 - 165 g/km	48.8	51.1	47.7	45.8	33.0	32.7	25.3	18.1	14.1	14.1	15.3
166 - 175 g/km	20.1	17.8	22.4	21.5	16.7	10.7	6.2	6.1	5.7	6.4	4.4
176- 185 g/km	17.6	16.7	12.2	12.8	9.5	9.4	7.5	5.4	3.5	2.5	2.6
186- 200 g/km	13.7	14.7	13.2	16.0	11.3	7.4	7.0	4.6	3.9	2.8	2.9
201 - 225 g/km	15.1	12.9	12.6	10.1	6.1	5.1	3.7	1.8	1.5	1.5	1.8
226 - 255 g/km	8.3	6.9	5.7	4.2	2.4	2.3	2.6	2.3	1.8	1.4	1.0
Over 255 g/km	7.5	5.6	5.7	5.2	3.4	2.2	1.2	0.6	0.5	0.5	0.5
Not known	3.5	2.1	1.4	1.5	1.0	0.8	0.6	0.5	0.7	0.7	0.6
Total	217.9	203.2	196.5	202.5	172.7	186.2	177.2	167.8	182.5	205.2	222.4
Avg CO2	166.9	165.6	164.4	162.2	156.3	148.6	143.4	138.2	133.2	128.4	124.4
									Column Percentages
Up to 100 g/km	0.0	-	0.0	-	-	0.7	1.3	2.7	7.1	12.5	16.3
101 - 110 g/km	-	0.6	1.7	2.0	2.8	4.3	5.2	9.1	9.5	11.4	15.7
111 - 120 g/km	3.5	2.8	2.8	3.1	7.0	13.3	16.8	16.8	17.3	21.0	21.7
121 - 130 g/km	3.4	4.6	5.1	4.7	6.4	8.3	15.6	17.0	21.6	19.4	16.4
131 - 140 g/km	11.6	11.6	12.8	18.9	21.3	22.3	19.1	18.7	16.7	12.8	10.7
141 - 150 g/km	19.4	17.5	16.0	13.6	14.1	13.3	11.6	12.1	10.4	8.3	6.2
151 - 165 g/km	22.4	25.1	24.3	22.6	19.1	17.5	14.3	10.8	7.8	6.9	6.9
166 - 175 g/km	9.2	8.8	11.4	10.6	9.7	5.8	3.5	3.6	3.1	3.1	2.0
176- 185 g/km	8.1	8.2	6.2	6.3	5.5	5.1	4.2	3.2	1.9	1.2	1.2
186- 200 g/km	6.3	7.3	6.7	7.9	6.6	4.0	4.0	2.8	2.1	1.4	1.3
201 - 225 g/km	6.9	6.4	6.4	5.0	3.5	2.7	2.1	1.1	0.8	0.7	0.8
226 - 255 g/km	3.8	3.4	2.9	2.1	1.4	1.2	1.5	1.4	1.0	0.7	-
Over 255 g/km	3.4	2.8	2.9	2.6	2.0	1.2	0.7	-	-	-	-
Not known	1.6	1.0	0.7	0.7	0.6	-	-	-	-	-	-
Total	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Source: DVLA//DVADfT - GB figures published as DfT table  VEH0256

Figure 13.3 New car average CO2 emissions, Scotland 2004-2014

Figure 13.4 First time car registrations, Scotland, by Emissions band, 2004-2014

Table 13.7:  Ultra-low emission vehicles (ULEV)¹ registered for the first time, Scotland, quarterly: January 2011 to September 2014

											Vehicles
Year	Month	Plug-in-Grant Eligible Cars	Non Plug-in-Grant Eligible Cars	Quadricycles	All Cars (inc. quadricycles)	Motor cycles & tricycles	Plug-in Grant Eligible Vans	Non Plug-in Grant Eligible Vans	All Vans	Other vehicles	Total
2011	Jan-Mar	14	27	0	41	4	0	14	14	4	63
2011	Apr-Jun	37	0	0	37	1	0	4	4	3	45
2011	Jul-Sep	14	2	0	16	3	0	1	1	0	20
2011	Oct-Dec	5	0	0	5	3	1	10	11	4	23
2012	Jan-Mar	25	1	0	26	1	0	9	9	2	38
2012	Apr-Jun	35	0	13	48	3	5	0	5	8	64
2012	Jul-Sep	34	0	1	35	0	25	5	30	1	66
2012	Oct-Dec	40	3	1	44	0	11	0	11	1	56
2013	Jan-Mar	26	0	0	26	0	4	0	4	0	30
2013	Apr-Jun	66	1	0	67	1	1	1	2	2	72
2013	Jul-Sep	53	3	1	57	0	3	0	3	3	63
2013	Oct-Dec	46	0	0	46	0	1	2	3	1	50
2014	Jan-Mar	128	0	0	128	0	9	0	9	2	139
2014	Apr-Jun	166	0	1	167	3	11	1	12	6	188
2014	Jul-Sep	266	1	2	269	0	10	2	12	5	286
2014	Oct-Dec	272	0	0	272	1	13	1	14	4	291
2015	Jan-Mar	365	0	8	373	2	28	1	29	6	410
2015	Apr-Jun	314	3	2	319	1	15	2	17	1	338
2015	Jul-Sep	276	5	1	282	1	14	2	16	3	302
2011	Whole year	70	29	0	99	11	1	29	30	11	151
2012	Whole year	134	4	15	153	4	41	14	55	12	224
2013	Whole year	194	1	1	196	1	9	3	12	6	215
2014	Whole year	832	1	3	836	4	43	4	47	17	904

1.  The Department for Transport uses the term 'ultra-low emission vehicles'  to refer to vehicles with significantly lower levels of tailpipe emissions than conventional vehicles.  In practice, the term currently refers to electric, plug-in hybrid and hydrogen fuel-cell vehicles.  For the purposes of this indicator, vehicles with fully electric powertrains, and cars with tail-pipe emissions below 75 g/km g/km of CO2 have been included at this stage. 
Source: DVLA//DVADfT - Published as DfT table  VEH0170
Notes & definitions (https://www.gov.uk/transport-statistics-notes-and-guidance-vehicle-licensing)

Table 13.8:  Ultra-low emission vehicles (ULEV)¹ licensed at the end of year, Scotland, quarterly: 2011 q1 to 2014 q3

										Vehicles
Quarter	Plug-in-Grant Eligible Cars	Non Plug-in-Grant Eligible Cars	Quadricycles	All Cars (inc. quadricycles)	Motor cycles & tricycles	Plug-in Grant Eligible Vans	Non Plug-in Grant Eligible Vans	All Vans	Other vehicles	Total
2011 Q1	14	60	0	74	73	0	93	93	203	443
2011 Q2	51	61	0	112	72	0	96	96	198	478
2011 Q3	64	63	0	127	68	0	98	98	200	493
2011 Q4	70	62	0	132	63	1	110	111	204	510
2012 Q1	97	61	1	159	67	1	117	118	205	549
2012 Q2	131	63	14	208	67	6	119	125	214	614
2012 Q3	167	63	15	245	60	31	122	153	212	670
2012 Q4	207	64	16	287	52	42	121	163	211	713
2013 Q1	242	63	16	321	47	48	121	169	209	746
2013 Q2	314	62	16	392	48	48	125	173	205	818
2013 Q3	367	63	15	445	47	55	120	175	207	874
2013 Q4	418	63	16	497	45	58	119	177	208	927
2014 Q1	543	63	16	622	43	70	119	189	213	1,067
2014 Q2	712	60	15	787	42	80	120	200	210	1,239
2014 Q3	984	64	17	1,065	35	89	120	209	221	1,530
2014 Q4	1,246	62	18	1,326	32	97	125	222	219	1,799
2015 Q1	1,604	66	27	1,697	34	113	126	239	230	2,200
2015 Q2	1,918	62	29	2,009	33	133	116	249	221	2,512
2015 Q3	2,210	51	29	2,290	31	150	109	259	216	2,796

1.  The Department for Transport uses the term 'ultra-low emission vehicles'  to refer to vehicles with significantly lower levels of tailpipe emissions than conventional vehicles.  In practice, the term currently refers to electric, plug-in hybrid and hydrogen fuel-cell vehicles.  For the purposes of this    indicator, vehicles with fully electric powertrains, and cars with tail-pipe emissions below 75 g/km g/km of CO2 have been included at this stage. 
Source: DVLA//DVADfT - Published as DfT table  VEH0130
Notes & definitions (https://www.gov.uk/transport-statistics-notes-and-guidance-vehicle-licensing)

Figure 13.5 Ultra Low Emission Vehicles licensed in Scotland - growth from 2011 Q1 to 2015 Q3

Table 13.9:  Number of new registrations by body type and propulsion type in Scotland during 2014 (Thousands)

Propulsion type
	Diesel	Electric diesel	Electricity	Fuel cells	Gas	Gas bi-fuel	Gas-diesel	Hybrid electric	New fuel tech-nology	Petrol	Petrol/gas	Steam	Grand Total
Body type												thousand
Agricultural	2.31	~	~	~	~	~	~	~	~	0.45	~	~	2.77
Buses & coaches	0.86	~	~	~	~	~	~	~	~	~	~	~	0.87
Cars	101.38	0.08	0.70	~	~	~	~	1.88	~	118.38	~	~	222.41
Goods - heavy	3.20	~	~	~	~	~	~	~	~	~	~	~	3.21
Goods - light	23.06	~	0.05	~	~	~	~	~	~	0.25	~	~	23.36
Motorcycles, mopeds & scooters	~	~	~	~	~	~	~	~	~	6.10	~	~	6.11
Others	1.90	~	0.81	~	~	~	~	~	~	0.11	~	~	2.84
Special purpose	~	~	~	~	~	~	~	~	~	~	~	~	~
Taxis	0.54	~	~	~	~	~	~	~	~	~	~	~	0.54
Tricycles	~	~	~	~	~	~	~	~	~	~	~	~	~
Grand Total	133.26	0.08	1.58	~	~	~	~	1.88	~	125.32	~	~	262.16

~ denotes fewer than 50.

Table 13.10:  Number of licensed vehicles by body type and propulsion type in Scotland as at 31 December 2014 (Thousands)

Propulsion type
	Diesel	Electric diesel	Electricity	Fuel cells	Gas	Gas bi-fuel	Gas-diesel	Hybrid electric	New fuel tech-nology	Petrol	Petrol/gas	Steam	Grand total
Body type												thousand
Agricultural	45.05	~	~	~	~	~	~	~	~	3.48	~	~	48.60
Buses & coaches	15.05	~	~	~	~	~	~	~	~	0.22	~	~	15.29
Cars	884.34	0.26	1.11	~	~	1.21	~	8.77	~	1472.78	0.82	~	2369.34
Goods - heavy	36.28	~	~	~	~	~	~	~	~	0.13	~	~	36.44
Goods - light	249.16	~	0.22	~	~	0.35	~	~	~	6.18	0.05	~	256.01
Motorcycles, mopeds & scooters	0.07	~	~	~	~	~	~	~	~	67.17	~	~	67.28
Not recorded	0.37	~	~	~	~	~	~	~	~	0.07	~	~	0.44
Others	17.91	~	3.67	~	0.09	~	~	~	~	1.25	~	~	23.02
Special purpose	0.32	~	~	~	~	~	~	~	~	0.05	~	~	0.39
Taxis	3.70	~	~	~	~	~	~	~	~	~	~	~	3.71
Tricycles	~	~	~	~	~	~	~	~	~	0.84	~	~	0.85
Grand Total	1252.30	0.30	5.10	~	0.10	1.60	~	8.80	~	1552.20	0.90	0.10	2821.40

~ denotes fewer than 50.