Scottish Government

Executive Summary

A Commitment to Mitigating Climate Change

In 2006, Scottish transport, including international aviation and shipping, accounted for 15.0 mega-tonnes of carbon dioxide equivalent (MtCO2e), or 24.4% of total Scottish greenhouse gas emissions. This figure, both in terms of absolute emissions and the proportion of total emissions, continues to grow on an annual basis.

Reducing emissions from transport is one of the National Transport Strategy's three key strategic outcomes. On 5th December 2008 the Scottish Government published the Climate Change (Scotland) Bill, which includes a commitment to reduce emissions by 50% by 2030, and by 80% by 2050. The finalised version also includes an interim target of 42% by 2020. These targets demonstrate a bold commitment by the Scottish Government. It signifies the importance Scotland places on playing its part in mitigating one of the most serious threats facing our world.

The Scottish Government's Transport Directorate wants to improve its evidence base on how it can contribute to meeting emission reduction targets and appointed Atkins in partnership with the University of Aberdeen to undertake a study to identify, analyse, and report on the policy options available to the Scottish Government.

Methodology

The study has been carried out using a seven stage methodology:

• Establishment of a preliminary long list of potential policy options;
• Identification of "ownership" of options;
• Finalisation and filtering of the policy option list;
• Comparison of Scottish and UK transport use and requirements;
• Establishment of the baseline 'business as usual' emissions scenario;
• Detailed assessment of policy options; and
• Packing of complimentary policy options into two alternative scenarios;
• Central Scenario - a package of policy options that could feasibly be deployed with a politically or publicly acceptable degree of "forcefulness", and
• Ambitious Scenario - a package of policy options, included all the measures from the Central Scenario which could be applied more forcefully, and also some policy options considered too ambitious for the Central Scenario.

Key Findings

Policy Options

The study has identified a broad range of devolved policy options that are available to the Scottish Government to mitigate transport's climate change impact in Scotland. In total 22 policy options have been identified and divided into seven sub-categories, these are summarised in the table below.

Devolved Policy Options

Abatement Potential of Individual Policy Options

Annual Abatement

The annual abatement potential of each policy option varies depending on:

• The scale of implementation - influenced both by rate of implementation and level of intensity; and
• The year under consideration - influence by a number of factors;
• increasing levels of implementation through time,
• increasing levels of reference traffic, and
• increasing efficiency of the vehicle fleet.

A number of broad patterns have emerged in relation to the relative performance of different types of policy options:

• The analysis undertaken as part of this study suggests that the Car Demand Management (Smart Measures) category has the greatest potential to reduce CO2 emissions. In particular the potential for travel planning considerably exceeds that for all other policy options, reflecting the range of approaches covered in the policy option (from workplace travel plans to individual travel marketing) and the associated scale of the target population;
• The fiscal policy options in the Car Demand Management (Fiscal/Infrastructure) category also offer significant abatement potential, however, the analysis suggests most of the infrastructure policy options in this category would offer significantly less potential; and
• Schemes involving extensive investment in the public transport network generally lie towards the bottom of the list in abatement terms.

Cumulative Abatement

The relative order of abatement potential for the policy options is broadly similar when cumulative abatement and annual abatement in 2022 are considered. However, some minor reordering is evident. This is a consequence of the policy options that are suitable for more rapid implementation performing slightly better and those with a longer build up time performing slightly less well by the cut off date.

Cost Effectiveness and Marginal Abatement Cost Curve ( MACC)

Combining the estimated cumulative abatement potential between 2010 and 2030 with the present value of costs incurred over the same interval provides an indicator of cost-effectiveness for each policy option, defined as follows. This can be broadly viewed as the cost in PV terms of each tonne of abatement achieved in total over the 20 year period by each policy option and forms the basis of the Marginal Abatement Cost Curve ( MACC). The MACC below illustrates the most cost effective policies.

Abatement Potential by Scenario

The model results suggest that the combined effect of the policy options in the Central Scenario would achieve an annual abatement of around 1.35 MtCO2 p.a. in 2022, whilst the Ambitious Scenario would achieve an additional 0.80 Mt CO2, representing a total of 2.15 Mt CO2 p.a. in 2022.

The estimated abatement potential of the Central Scenario therefore accounts for approximately 15% of the difference between the Baseline emissions (including action at the EU/ UK level) and the 2022 level of a 44% reduction (as a proxy for the 42% reduction target by 2020) from 1990 total transport emissions ¹. The contribution is nearly 25%, if the comparison is restricted to emissions from the land transport modes targeted by the scenario. The equivalent figures for the Ambitious Scenario are just over 20% of the target difference if all transport emissions are considered and 35% if the focus is on land transport alone.

Abatement Beyond 2022

The modelling results suggest that the total absolute abatement potential from the Ambitious Scenario will be very similar in 2030, although the balance between the contributions from different policy options will have changed. For instance, those policy options focussing on efficient driving will have become less significant (as the vehicle fleet becomes increasingly dominated by electric and hybrid vehicles) and those with longer term effects (such as land use planning) will become gradually relatively more significant.

Forecasts of emissions levels and the impact of abatement policy options over the longer term to 2050 inevitably have to be less detailed than those for shorter timescales due to the uncertainties involved in attempting to forecast travel patterns, behaviour and technology in 40 years time.

However it is possible to anticipate likely important future trends. The key influence is likely to be the anticipated increasing use of electricity to power the vehicle fleet either directly or through the production of hydrogen. Sources such as the Committee on Climate Change report and the King Review suggest that such vehicles could feasibly be the standard by 2050.

In this case, emphasis will increasingly be on energy policy and technology and the nature and viability of the electricity network and vehicles rather than the direct reduction in emissions from vehicle exhausts. Suitable vehicle technology and the provision of very low carbon electricity (generated for instance by renewable energy) could potentially result in very low transport carbon emissions levels. However, the role of supporting transport policy options will remain important. Although some of the policy options assessed above will become less relevant as they are related to current technology (particularly those encouraging more efficient driving), the emphasis on improving efficiency and reducing demand will continue to be important. This will potentially be aimed less at reducing carbon emissions directly and more at ensuring demand remains at a level and in a form that could be viably served by the electricity network.