The Scottish Government

« Previous | Contents | Next »

Listen

8 Summary of Base Year Position

8.1 Energy and Related CO ₂ emissions

A summary of the energy-related CO ₂ emissions from Scotland in 2002 is presented in Table 31 below. For this summary, electricity has been considered as kWh of electricity consumed within Scotland multiplied by the standard DUKES kg CO ₂/kWh factor.

Total consumption in Scotland was 174.5 TWh (628 PJ) of delivered energy, responsible for 45.1 Mt CO ₂ (12.3 Mt as C). Using a ratio of primary energy: delivered energy of 2.60:1 for electricity and 1.00:1 for fossil fuels, the total primary energy consumed would be 221.5 TWh.

These figures are the Scottish Energy Study 'declared' energy- CO ₂ emissions for 2002. Their use should always be accompanied by a caveat with some description of how they have been derived, because the method used to calculate emissions could have a significant effect on the value.

Table 31: Energy CO ₂ emissions used for the Scottish Energy Study

Figure 24: Contribution to CO ₂ by fuel type

8.2 Energy PLUS Non-Energy CO ₂

A summary of the energy plus non-energy CO ₂ emissions is presented in Table 32.

Table 32: Summary of energy CO ₂ and non-energy CO ₂

Figure 25: Scottish CO ₂ contributions in perspective

Table 33: Summary of energy CO ₂ and non-energy CO ₂, ignoring the carbon 'sink'

The above analysis would suggest that it is important to consider energy and related CO ₂ emissions in relation to all CO ₂ emissions.

In fact, this argument could be extended to all GHGs. A similar study for Wales suggests that non- CO ₂GHGs (especially methane and nitrous oxide) can add an additional 20% to the overall GHG 'basket'. Furthermore, some of the 'problem' GHG emissions, in particular methane, can also be an opportunity, i.e. an alternative (effectively renewable) fuel source. Efforts to capture and burn fugitive emissions of methane can act as a double benefit to the environment - reducing requirements for fossil-fuel energy and decreasing the overall potency of the GHG basket.

8.3 MAPPING OF SCOTTISH & UKCO ₂ EMISSIONS

This section provides a pictorial representation of the geographical distribution of CO ₂ emission sources in Scotland and the UK as a whole for 2003. This is represented in terms of CO ₂ as carbon - assuming all carbon emissions converted into CO ₂. The following maps are developed from the NAEI dataset using a mapping methodology that is described in full on the NAEI website ⁵⁷. These maps do not include the impacts of CO ₂ sinks.

Four maps have been produced for the Scottish Energy Study, Figure 26 to Figure 29. These include variants that show CO ₂ emissions from all sources (energy use, industrial processes and land use), as well as variants that only show CO ₂ emissions that result from energy use:

• All CO ₂ - All UK.
• Energy CO ₂ only - All UK.
• All CO ₂ - Scotland only.
• Energy CO ₂ only - Scotland only.

The maps include a wide range of sources of CO ₂. At one extreme, the emissions in rural areas tend to be low level and diffuse. At the other extreme, large industrial sites (power stations, refineries, chemical plants etc.) are very significant sources of CO ₂ emissions at a single point. Hence the scale used to represent these extremes is a non-linear one. The scale starts with a level of 0 to 1 tonne of CO ₂ (as carbon), however, the highest level on the scale is over 2,000 tonnes of CO ₂ (as carbon).

Figure 26: 2002 UK emissions map of total CO ₂ (as C)

Figure 27: 2002 UK emissions map of energy CO ₂ (as C)

Figure 28: 2002 Scottish emissions map of total CO ₂ (as C)

Figure 29: 2002 Scottish emissions map of energy CO ₂ (as C)

Examining and comparing the two Scottish maps, the following features can be observed:

• The areas with the greatest concentrations of CO ₂ sources are the same in both maps - showing that energy use accounts for the most intense areas of emissions. Fuel combustion also results in emission of other pollutants, e.g. SO ₂, NO _x, dust etc. Hence, this means that these areas of relatively high CO ₂ emissions are associated with higher emissions of other environmental pollutants also.
• The areas showing relatively high emissions include the main urban areas of: Glasgow, Edinburgh, Aberdeen and Dundee, with significant emissions in Lanarkshire, the Ayrshire coast, around Grangemouth, around Dunfermline and the South Fife coast. These emissions result from business activity (industry & services), domestic fuel use and transport.
• Some road links show up clearly, particularly when there is an absence of other industrial sources of CO ₂ that may mask the local transport emissions. Hence, the main motorway routes can be seen (M8, M74 etc.) as well as the major trunk roads (A7, A702, A65, A76, A80 and the A9).
• The impact of marine transport can also be seen, particularly focused around Peterhead, Aberdeen, Fraserburgh and in the Firth of Forth around Grangemouth, and also at a lower level around Stranraer and Lerwick.
• Comparing the map of all sources of CO ₂ with the energy sources map, the areas of significant land-use CO ₂ can be identified. These include the flow country in Caithness, and significant parts of Aberdeenshire, Angus, East Lothian and the Borders.

8.4 Comparison of CO ₂ EMISSIONS FOR 2002 with 2000 & 2001

One of the aims of developing an energy 'footprint' for Scotland for a given base year is to draw on these data to project scenarios for 2010, 2020 and beyond. When selecting the base year, it is important that it is representative and is not biased by factors such as plant outages.

This section describes a brief analysis of CO ₂ emissions for 2000 and 2001, to compare with those of 2002, making use of NAEICO ₂ emissions data.

8.4.1 Approach adopted

Total CO ₂ emission figures from the NAEI study are higher than those figures generated by the Scottish Energy Study, in particular, because NAEI attributes all CO ₂ emissions associated with electricity to the point of generation, regardless of whether this electricity is exported or used in the country.

According to the NAEI analyses for Scotland, the 2000 and 2001 CO ₂ totals were similar, but 2002 was approximately 6% less than 2001.

Table 34: Comparison between Scottish CO ₂ emissions 2001 vs. 2002

More details are given in Appendix 9. An attempt was made to account for the reason that the total was lower for 2002, as summarised below:

• The NAEI report suggests emissions from electricity generators fell from 22.8 Mt CO ₂ in 2000 to 20.9 Mt in 2002. Also, in 2001, 8.7 TWh of electricity was exported whereas in 2002 this fell to 8.0 TWh⁵⁸. There were also changes to the primary fuel mix ⁵⁹.
• There also appears to have been a fall in transport-related energy CO ₂, from 10.47 Mt in 2000 to 10.45 in 2001 and then 9.86 Mt in 2002, although the reasons for this are unclear.
• Finally, the LUCF data are questionable.

Overall, 2002 is a reasonably representative year on which to base future projections of energy use, although it should be noted that CO ₂ emissions for this year are 3 Mt (or 6%) lower than the two preceding years.

« Previous | Contents | Next »