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Scottish Energy Study: Volume 1: Energy in Scotland: Supply and Demand

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7 Non-energy CO 2 Emissions from Scotland

Although the focus of this study is on CO 2 emissions arising from energy use, other activities, in particular emissions from soil, also give rise to significant emissions of CO 2. For Scotland, non-energy CO 2 emissions are very high, of the same magnitude as those from some of the energy 'demand' sectors, and it was thought useful to make some reference to them, to set energy-related emissions in context.

Information in section 5 draws on the NAEI's 'Greenhouse Gas Inventories for England, Scotland, Wales & Northern Ireland: 1990 - 2003', published in September 2005 54. Details of the report have also been discussed with several of the NAEI report's authors.

In this category, CO 2 emissions stem from:

  • Decomposition of organic materials in soils, in particular, Scotland's high-organic soils.
  • Fuel transformation and other industrial processes.

In contrast, Scotland can be credited as a carbon 'sink' from its forest growth.

7.1 Land Use Change & Forestry ( LUCF)

Table 28: Scottish non-energy CO 2: LUCF (ktonnes)

Year

2000

2001

2002

LUCF - emissions

5,134

5,112

5,041

Carbon sink

-9,746

-9,779

-9,894

LUCF balance

-4,612

-4,667

-4,853

The majority of Scotland's land-use change emissions arise from decomposition of organic materials in Scotland's peaty soils. Emissions from LUCF constituted around 5.0 Mt CO 2 for 2002, these are more than outweighed by the carbon sinks from forestry and other land use activities. Hence, Scotland represents a carbon sink of 4.8 Mt CO 2 from 'Changes in Forests and Other Woody Biomass'. Figures are similar to 2000 and 2001 estimations 55.

7.2 Fugitive, industry and other sources

Fugitive emissions (typically flaring) from oil and gas processing were 1,061 kt of CO 2 in 2002. This is broadly similar to previous years. The figure is large in Scotland compared with the rest of the UK, simply because the oil and gas industries are proportionally larger.

Industrial processes also produce emissions from non-combustion sources such as limestone in cement and glass-making, plus primary aluminium smelting. Together these processes emitted around 1% of the Scottish total in 2002. They are small in comparison to the LUCF contribution.

Finally, waste incineration represents 19 kt of CO 2 emissions.

Table 29: Other sources of Scottish non-energy CO 2

Source

Emission (kt)

Fugitive emissions from oil and gas

1,061

Minerals (cement & glass)

455

Metals (aluminium)

64

Waste incineration

19

Total

1,599

7.3 Overall non-energy CO 2

Table 30: Scottish non-energy CO 2: overall - based on NAEI

Source

Emission (kt)

LUCF - emissions

5,041

Carbon sink

-9,894

Other sources

1,599

Total

-3,254

As commented, Scottish soils emit some 5.0 Mt of CO 2 per year. The overall contribution from land use is in fact a carbon sink if one includes the CO 2 absorbed by forest growth.

However, this leads to an interesting accounting point regarding the CO 2 sequestration figure from growing wood. Currently, Scotland is 'credited' with approximately 6.8 Mt CO 2 per year from forest and wood growth. This is the standard Intergovernmental Panel on Climate Change ( IPCC) method by which carbon sequestration is reported. However, applying this methodology to a nation could, in fact, distort the real Scottish CO 2 balance and give a misleading picture. Unless the carbon is permanently sequestered, it will eventually work its way back into the carbon cycle, through burning or decomposition 56.