Select Committee on Environmental Audit Ninth Report


1. The Prime Minister's Foreword to the updated UK Climate Change Programme, published in March 2006, underlined the Government's recognition of the scale and urgency of the challenge posed by global warming:

Climate change is probably the greatest long-term challenge facing the human race. […] The scientific evidence is now overwhelming. […] If the anticipated growth in emissions is left unchecked, global average temperatures could be as much as 5.8C higher by the end of this century, with a devastating impact on our economy and natural world, in the UK and, above all, in the most vulnerable developing countries.[1]

2. Transport has an especially important role to play in responding to the challenge of averting dangerous climate change. The Prime Minister was right to emphasise this in the letter of appointment he sent to the new Secretary of State for Transport in May, where he wrote: "in particular transport will be critical to our long-term goal of reducing carbon emissions."[2]

3. Progress to date indicates both that reducing carbon emissions from transport is particularly challenging, and that the Department for Transport (DfT) needs urgently to accelerate its efforts: transport is the only sector of the UK economy in which carbon emissions were higher in 2004 than the baseline year of 1990, and the only sector in which emissions are projected to be higher in 2020 than in 1990.[3]

4. Transport is an especially challenging sector in which to reduce carbon emissions largely because it is so dependent on oil: 99% of all transport in the UK currently runs on oil products, and transport accounts for 74% of the UK's consumption of oil.[4] While alternatives to fossil fuels within the transport sector are being increased, these are growing from a very low starting point; and there remain profound difficulties in finding alternatives to oil in aviation, as well as, to a somewhat lesser extent, in shipping and long distance road transport. Additionally, transport is obviously intimately involved in transactions of all material goods; it has been estimated, for instance, that 95% of all goods in the shops currently arrive there using oil.[5] This means that it may be especially difficult to decouple carbon emissions in the transport sector from economic growth.

5. However, in the case of road transport, the principal source of emissions from transport, technological advances have already made available low emission engines. If these were more widely used in cars and lorries, significant reductions in carbon emissions could be achieved quickly without either inhibiting economic growth or requiring uncomfortable changes in lifestyles.

6. Notwithstanding the areas in which there are undoubted practical difficulties, then, the fact that rapid progress is possible, but that transport stands out for having consistently rising emissions, raises major questions over whether the Department for Transport is taking the need to tackle climate change seriously enough. This report sets out to answer this question, and to make practical recommendations to improve future progress.

Focus of this report

7. In recent years our predecessor Committee issued four reports on aviation and the environment. [6] This report builds on but expands beyond those reports, to tackle the full range of transport's contributions to climate change, notably road transport. In addition, this report forms part of the Committee's policy of examining climate change as our overall priority for this Parliament, and complements our evidence sessions with the new Secretary of State for Environment, and other witnesses, on the UK Climate Change Programme 2006.[7]

8. Two main notes on the scoping of this report need to be made at the outset. First, this report focuses solely on the contributions of transport to global warming (mainly through emissions of carbon), and not at all on emissions of those gases and particles (eg, from exhaust pipes) which are mainly of concern in relation to air quality and related health issues. Second, while this report does engage with the potential of biofuels, it does not focus on this area in detail; in this, the Committee has been mindful not to duplicate the concurrent work of the Environment, Food and Rural Affairs (EFRA) Committee, whose report Climate change: the role of bioenergy will be published later in 2006.

9. In carrying out this inquiry we considered over 70 memoranda, and held eight oral evidence sessions, culminating in a session with the new Secretary of State for Transport, Douglas Alexander MP. In addition, we travelled to Sweden, primarily to learn about its policies to reduce oil use, as well as to the Netherlands, to learn about a variety of policies including the national promotion of "eco-driving" and the introduction of a tax on domestic aviation. We would like to express our gratitude to all who contributed to the inquiry.

The nature of the challenge for DfT

10. As the Climate Change Programme 2006 (CCP 2006) announced, the UK is on course to meet its Kyoto target, but is not on course to meet its domestic target to reduce CO2 emissions by 20% by 2010.[8] Carbon dioxide emissions were 161.5MtC[9] in 1990; in 2004 they stood at 152.5MtC, a reduction of 5.6%, only just a quarter of the way towards the target for 2010. The Government estimates that, with the additional package of measures unveiled in CCP 2006 and subject to the UK's recently proposed carbon allocation within the second phase of the EU Emissions Trading Scheme, CO2 emissions will be around 16.2% below 1990 levels by 2010, closer to though still not meeting the target.[10]

11. To what extent is transport responsible for the slow progress to date in meeting the 2010 target? Certainly, transport is both a major source of emissions and the only sector of the economy from which CO2 has been rising consistently since 1990. Measured in terms of end user emissions,[11] transport within the UK (i.e., excluding international aviation and shipping refuelling in the UK) was responsible for 43.1MtC in 2004 (or around 28% of total UK domestic carbon emissions), a rise in transport emissions of around 10% since 1990. Government projections (absent the new measures announced in CCP 2006) are for this trend to continue up to 2015 before starting to decline very gently, with internal UK transport emissions estimated to lie at 45.3MtC in 2020, 16% higher than 1990 levels and 5% higher than 2004 levels, and with transport making up some 31% of total carbon emissions for 2020. These trends contrast strongly with other sectors of the economy: the "Agriculture, forestry and land management", "Public", "Business", and "Domestic" sectors all saw reductions in carbon emissions in 2004 from 1990 levels—by around 53%, 28%, 12% and 2% respectively.

12. When international aviation and shipping are included,[12] these trends are even starker. Carbon emissions from international flights departing the UK stood at 9.1MtC in 2004, a rise of 111% from 1990, and equivalent on their own to 5% of the UK's total carbon emissions in 2004. This is without even factoring in the extra contribution which aviation makes to global warming due to the radiative forcing of the greenhouse gases it releases at altitude. [13] Adding international aviation and shipping, total CO2 emissions (not counting radiative forcing) from UK transport stood at 53.9MtC in 2004 (some 33% of total UK emissions from all sectors), a rise in transport emissions of 18% from 1990.

13. While aviation has seen the steepest rises in emissions, the most significant source of emissions within the transport sector is road transport; and here, too, emissions are still rising. Measuring emissions on a "by source" basis,[14] road transport emitted some 33MtC in 2004 (21% of domestic UK carbon emissions in that year), an increase of around 10% since 1990.[15] Meanwhile, latest projections from the DTI are for road transport emissions (absent the new measures in CCP 2006) to rise to 34.6MtC in 2010, and again to 36.2 MtC in 2020.[16] Carbon emissions from private cars have risen by 8% between 1990 and 2004, while emissions from Heavy Goods Vehicles (HGVs) have risen by 25%.[17]

14. Figure 1 summarises these rises in carbon emissions from transport in the context of total UK emissions. Unlike the equivalent table in the Climate Change Programme 2006, this adds figures for international aviation and shipping to present total transport emissions, for added transparency. Figure 2 depicts the share of emissions by sector (for 2004), to illustrate at a glance the relative contribution of transport. Figure 3 shows the percentage change in emissions per sector since 1990, illustrating the fact that, measured on a "by source" basis, two of the three sharpest increases have come from aviation and road transport.

15. One final point needs to be made about these figures. Government projections for future years emissions should be treated with a certain degree of caution. Going by their track record, there is some reason to expect that, unless new measures are added, these projections will have to be revised upwards in time. The Environmental Audit Committee has several times observed that Government projections have often overestimated the future impacts of carbon reduction measures and underestimated total future emissions.[18] In particular, we have expressed doubts about DfT's projections for carbon emissions from aviation; while a recent paper by Steer Davies Gleave for Transport 2000 has severely, and with great weight of analysis, criticised the accuracy of emissions projections from road transport.[19] Further, both that paper and more than one memo we received[20] demonstrated that there are important discrepancies between the emissions projections made by DfT and those made by the DTI. The Government should review the different methods used by these departments, and look at establishing a more concerted and accurate approach for greater certainty and clarity.

Figure 1 End user carbon emissions in MtC, by sector
Sector1990 19952000 20042010 20152020
Business68.861.2 60.360.556.4 5858.1
Transport39.2 39.840.9 43.144.845.7 45.3
Transport as % of total(1)24% 27%27% 28%31%31% 31%
Intl aviation*4.35.6 8.39.1n/a  n/an/a
Intl shipping1.91.9 1.61.6n/a n/an/a
Total transport (incl intl aviation & shipping)* 45.447.3 50.853.8n/a n/a n/a
Total transport as % of total(2)* 27%30%32% 33% n/a n/an/a
Domestic42.439.1 39.841.736.5 3836
Public7.97.2 65.5
Total (1) emissions by sources minus removals by sinks 161.5149.9 149152.5144.3 149146.6
Total (2) emissions, minus sinks, adding intl aviation and shipping* 167.7157.4 158.9163.2n/a n/an/a
 Sources: Table 5, UK Climate Change Programme 2006; Figure 20int, "UK Greenhouse Gas Emissions - Latest Figures", 30 March 2006,

Note: *Does not include radiative forcing of emissions from aviation. Actual MtCe are therefore likely to be considerably higher than shown.

Figure 2 Total transport (including international aviation and shipping) makes up 33% of total UK carbon emissions

 Sources: Table 5, UK Climate Change Programme 2006; Figure 20int, "UK Greenhouse Gas Emissions - Latest Figures", 30 March 2006,

Figure 3 International aviation is the fastest growing source of emissions, road transport the third fastest (measured by "source", rather than by "end user")

Sources: Figure 6int, "Carbon dioxide emissions by source", Figure 20int,"Greenhouse gas emissions arising from use of fuels from UK 'international bunkers': "UK Greenhouse Gas Emissions - Latest Figures", 30 March 2006,

1   Department for the Environment, Food and Rural Affairs (Defra), Climate Change: The UK Programme 2006, Cm 6764, March 2006, p iii Back

2   "Letter from PM to Douglas Alexander", 10 May 2006, Back

3   In "end user" terms. "Table 5: Carbon dioxide emissions by end user", Cm 6764, p 28 Back

4   "The 2006 Energy Review Regional Stakeholder Seminar: Energy RD&D and Transport", Department of Trade and Industry, 23 February 2006,; Department of Trade and Industry (DTI), The Energy Challenge, Cm 6887, July 2006, p 126 Back

5   Jeremy Leggett, The Empty Tank (New York, 2005), p 3 Back

6   Environmental Audit Committee, Ninth Report of Session 2002-03, Budget 2003 and Aviation, HC 672; Third Report of Session 2003-04, Pre-Budget Report 2003: Aviation Follow-up, HC 233; Seventh Report of Session 2003-04, Aviation: Sustainability and the Government Response, HC 623; Eleventh Report of Session 2003-04, Aviation: Sustainability and the Government's second response, HC 1063


7   Uncorrected transcript of oral evidence taken before the Environmental Audit Committee on 12, 13, and 20 July 2006 Back

8   The UK has three overall targets for reducing greenhouse gas emissions: the Kyoto target of reducing emissions of the basket of six greenhouse gases by 12.5% below base year levels by 2008-2012; the domestic target of reducing carbon dioxide (CO2) emissions by 20% below 1990 levels by 2010; and the longer term target of cutting CO2 emissions by 60% by 2050, with real progress by 2020. Neither the Kyoto nor the 2010 domestic targets encompasses emissions from international aviation and shipping travelling to and from the UK. Back

9   All greenhouse gas emissions are expressed throughout this report as million tonnes of carbon equivalent (MtCe). One tonne of carbon is contained in 3.67 tonnes of carbon dioxide (which is the ratio of the molecular weight of carbon dioxide to the atomic weight of carbon). Other greenhouse gases are expressed in terms of carbon equivalent by multiplying their emissions by their global warming potential relative to carbon dioxide, and dividing by 3.67.


10   "UK announces measures to move to low carbon economy", Defra press release 291/06, 29 June 2006 Back

11   In this classification, the emissions from power stations, refineries and other energy supply industries are re-allocated to the end users of electricity, petroleum products and other fuels. Climate Change: The UK Programme 2006 states: "This classification gives the most complete account of the relationship between emissions and the production of goods and services." Cm 6764, p 27 Back

12   "Emissions from international aviation and shipping can be estimated from refuelling from bunkers at UK airports and ports (whether by UK or non-UK operators). […] Under the guidelines agreed for UNFCCC, reporting emission from international aviation and shipping are not included in the UK's emissions, but these estimates are reported as memo items in national greenhouse gas inventories." "UK Emissions of Greenhouse Gases - Latest figures", Defra, 2006, Back

13   See paras 139-140.


14   In other words, counting only the emissions from vehicles' tailpipes, and discounting the emissions arising from the oil refining process required to supply the fuel for road transport. Back

15   "UK Emissions of Greenhouse Gases - Latest figures", Defra, 2006, Back

16   "Table 18", DTI, UK Energy and CO2 Emissions Projections: Updated Projections to 2020, February 2006, p 32 Back

17   Department for Transport (DfT), Transport Trends: 2005 Edition, January 2006, "Trends 8.7b and 8.7c", pp 92-3 Back

18   Most recently in the Environmental Audit Committee's Sixth Report of Session 2005-06, Keeping the Lights On: Nuclear, Renewables, and Climate Change, April 2006, paras 23-28. Back

19   Driving up CO2 Emissions from Road Transport: An Analysis of Current Government Projections, Transport 2000, July 2006 Back

20   Ev2, Ev29 Back

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