Scottish Greenhouse Gas Emissions 2014

Section B. Results - Net Sources of Scottish Greenhouse Gas Emissions

2014 figures

Chart B1 presents the sources and sinks of Scottish Greenhouse Gas Emissions in 2014, grouped by Scottish Government sector.

Chart B1. Sources of Scottish Greenhouse Gas Emissions, 2014. Values in MtCO ₂e

Main points

• In 2014, Energy supply was the largest source of net emissions (13.8 MtCO ₂e), followed by Transport (including International Aviation and Shipping) (12.9 MtCO ₂e) and Agriculture and Related Land Use (10.7 MtCO ₂e).
• Emissions from Business and Industrial Processes and the Residential sector were the next largest net emissions sources (8.7 MtCO ₂e and 5.9 MtCO ₂e respectively).
• The combined total of emissions from the other net sources (Waste Management, Development and Public Sector Buildings) was less than 5 MtCO ₂e.
• Forestry was the only aggregate sector in which there has been a net emissions sink (-10.2 MtCO ₂e).

Table B1. Scottish Greenhouse Gas Emissions by Gas and by Scottish Government Source Sector, 2014. Values in MtCO ₂e

	TOTAL	Percentage share by sector	Carbon dioxide	Methane	Nitrous oxide	Fluorinated gases
TOTAL	46.7	100.0%	34.4	7.5	3.3	1.5
Energy Supply	13.8	29.7%	13.3	0.5	0.1	0.0
Transport (including International Aviation and Shipping)	12.9	27.7%	12.8	0.0	0.1	0.0
Transport (excluding IA&S)	10.6	22.8%	10.5	0.0	0.1	0.0
International Aviation and Shipping (IA&S)	2.3	4.9%	2.3	0.0	0.0	0.0
Agriculture and related land use	10.7	22.8%	3.2	4.7	2.7	0.0
Business and Industrial process	8.7	18.5%	7.2	0.0	0.1	1.3
Residential	5.9	12.6%	5.6	0.1	0.0	0.2
Waste Management	2.2	4.8%	0.0	2.2	0.1	0.0
Development	1.6	3.4%	1.5	0.0	0.1	0.0
Public Sector Buildings	1.1	2.3%	1.1	0.0	0.0	0.0
Forestry	-10.2	-21.8%	-10.2	0.0	0.0	0.0

Main points

Carbon dioxide was the main greenhouse gas emitted or removed in most sectors, with the exceptions of the Agriculture and Related Land Use and Waste Management sectors.

• Methane was the main net gas emitted in the Agriculture and Related Land Use sector (4.7 MtCO ₂e), followed by carbon dioxide (3.2 MtCO ₂e) and nitrous oxide (2.7 MtCO ₂e).
• Almost all emissions in the Waste Management sector were emitted in the form of methane (2.2 MtCO ₂e)

Where F gases are emitted, they have been in relatively small amounts via the Business and Industrial Process source sector, as well as in the Residential sector.

Key Trends By Scottish Government Source Sector

Chart B2 presents the main sources of Scottish Greenhouse Gas Emissions in Scotland from 1990 to 2014, broken down by Scottish Government source sector. Note that for the purposes of presentation, some sectors have been grouped together on this chart. Chart B3 and Chart B4 specifically explore the trend in Energy Supply emissions. Chart B5 contains information on the absolute and percentage reductions in greenhouse gas emissions in every Scottish Government source sector over the entire time period, with Chart B6 containing the same information for the latest year.

Chart B2. Main Sources of Greenhouse Gas Emissions in Scotland, 1990 to 2014. Values in MtCO ₂e

Main Points

Most sectors exhibit a general downward trend between 1990 and 2014, most clearly evident since 1998.

• In all years, energy supply is the main source of greenhouse gas emissions, although it has a seen a sharp fall in 2013 and 2014. This is partly linked to the closure and mothballing of power stations and means that energy supply emissions in 2014 are now 0.9 MtCO ₂e higher than emissions from transport (including international aviation and shipping). The chart shows that energy supply is a very volatile sector. This is driven by the fact that energy demand is linked to the ambient temperature, particularly during the winter months; and fuel used for electricity production, which in turn is partly driven by the price of coal relative to "cleaner" fuels. Charts B3 and B4 demonstrate these effects in more detail.
• Much of the fall in emissions from the Business and Industrial Process sector occurred between 1990 and 1995. This has been driven by a decline in emissions from manufacturing and the iron and steel industry over this time period.
• Net emissions from the agriculture and related land use sector have seen a gradual decline between 1998 and 2014, which can be linked to the impact of historic changes in land use, change to cropland and grassland and also a decline in cattle and sheep numbers.
• Emissions from transport (including international aviation and shipping) have seen a small overall reduction between 1990 and 2014. Emissions in this sector rose to a peak in 2007, before falling slightly. The recent falls in emissions reflects a number of factor including changes in emissions from cars stemming from improvements in car energy efficiency. Road transport emissions have been affected by changes in the make-up of the passenger car fleet. In recent years, there has been an increase in more fuel efficient diesel engines compared with petrol vehicles.
• Residential emissions have shown a downward trend between 1990 and 2014, although they have fluctuated substantially in recent years and are partly generated by heating of homes. Residential emissions in 2014 were the lowest in the series, due to the warmer external temperatures in that year.
• Waste management emissions have fallen between 1998 and 2014. This is due to the progressive introduction of landfill gas being captured and used for energy. There could also be other factors which are contributing to this reduction such as improvements in the standards of landfill sites and changes to the types of waste going to landfill.
• The size of the net carbon sink from forestry increased between 1990 to 1999, before remaining broadly constant in more recent years. Between 1990 and 2014, there has been an increase in the area of forest land. However, the rate at which land is being converted to forestry from other land uses has decreased over time. This is partly because the rate of afforestation has decreased over the last 40 years. In addition, conifer plantations, which were established in the mid-20th century, have reached their planned rotation age and are now being felled and replanted - leading to a fairly constant level of carbon sequestration since 1999, albeit with a slight reduction in the sink in recent years.

Chart B3 shows that the generation of Scotland's electricity changes over time. Emissions from the electricity supply sector (such as power stations) are associated with these changes.

Chart B3. Generation of Electricity by Fuel, Scotland, 2004 to 2014. Percentage of Electricity Generated by Year

Data obtained from DECC Energy Trends, published December 2015 ^[3]

Main Points

• The share of Scottish electricity generation arising from the renewables sector (including hydro natural flow) has increased from 11.7 per cent in 2004 to 38.0 per cent in 2014.
• There was a sharp drop in the proportion of electricity generation coming from gas between 2013 and 2014 (from 10.3 per cent to 5.4 per cent). This is likely to be the result of a gas fired power station being mothballing in 2014. This latest drop continues the decline in the share of electricity generation from gas from 2008 onwards, when it was 23.2 per cent.
• The proportion of electricity generation coming from coal has changed little between 2013 and 2014. However, the amount of electricity generated from coal has fallen between 2013 and 2014. This is likely to be because of the closure of a coal fired power station in the early months of 2013. Overall, there has been a fall in the proportion of electricity generated from coal since 2006, although this series is volatile, with 29.5 per cent of Scottish electricity supply being fuelled by coal in 2010.
• A third of Scotland's electricity supply came from nuclear energy in 2014. This represents an increase from 2007, when nuclear energy represented 25.7 per cent of Scotland's electricity supply.

Chart B4 shows the gas and coal prices for large users in the UK. The use of coal rather than gas in electricity generation can be sourced to these price effects in many cases. In 2014, the relative price of coal per kilowatt hour was slightly less than half that of gas, although it was higher than in 2013.

Chart B4. Gas and Coal Prices for Large Users in the UK (2004 to 2014) - pence per kWh

Data obtained from DECC: Digest of UK Energy Statistics ^[4]

Long term (1990 to 2014) and short term (2013 to 2014) trends by sector

Chart B5 shows how emissions have changed between 1990 and 2014 in all source sectors. Chart B6 shows how emissions have changed between 2013 and 2014.

Chart B5. Change in Net Emissions by Scottish Government Sector Between 1990 and 2014 - in MtCO ₂e, and percentage changes ^[5]

Chart B6. Change in Net Emissions by Scottish Government Sector between 2013 and 2014 - in MtCO ₂e, and percentage changes ^[6]

Total Emissions

Overall, there has been a 30.5 MtCO ₂e (39.5 per cent) decrease in net emissions between 1990 and 2014 and there has been a 4.4 MtCO ₂e (8.6 per cent) decrease in net emissions between 2013 and 2014.

Energy Supply

This sector has seen an 8.9 MtCO ₂e (39.2 per cent) fall in emissions between 1990 and 2014 - the largest absolute fall of any sector. Charts B2 to B4 shows that this series is very volatile. This is largely driven by changes in the fuel mix for electricity production. The Energy Supply sector also saw the largest absolute decrease of any sector between 2013 and 2014 - a 2.1 MtCO ₂e (13.4 per cent) decrease.

The largest contributor to the reduction in energy supply emissions between 2013 and 2014 has been power stations. In particular, a gas fired power station was mothballed in May 2014. A coal fired power station was also closed in March 2013 with some remaining emissions being reported for 2013, but not in 2014. There have also been falls in emissions from combustion in refineries and from gas production between 2013 and 2014.

Residential

This sector has seen a 2.1 MtCO ₂e (26.0 per cent) fall in emissions between 1990 and 2014. Between 2013 and 2014, there was a 1.2 MtCO ₂e (16.4 per cent) fall in residential emissions - the largest percentage reduction of any source sector in the latest year. Residential emissions are partly generated by space-heating homes and thus are related to external temperatures. The mean annual temperature in 2014 in Scotland was the highest in a series going back to 1910. It was 0.93°C higher than in 2013 and 0.98°C higher than the 1981-2010 average ^[7] . Chart B7 shows that the first 6 months of 2014 were considerably warmer than in the equivalent period in 2013 and the 1981-2010 average. As a result of this relationship to external temperatures, residential emissions can exhibit some large annual fluctuations.

Chart B7. Mean air temperature by month, Scotland. 2013 and 2014 and 1981-2010 average. Values in °C

Data obtained from Met Office, May 2016 ^[8]

Waste Management

This sector has seen a 7.6 MtCO ₂e (77.3 per cent) fall in emissions between 1990 and 2014 - the largest percentage fall of any sector over this time period. This is due to the progressive introduction of landfill gas being captured and used for energy and due to the reduction in biodegradable municipal waste going to landfill. There could also be other factors which contribute to this reduction, such as improvements in the standards of landfill and changes to the types of waste going to landfill. Between 2013 and 2014, the Waste Management sector saw a fall of 0.3 MtCO ₂e (12.8 per cent).

Business and Industrial Process

This sector has seen a 5.7 MtCO ₂e (39.6 per cent) fall in emissions between 1990 and 2014. As shown in Chart B2, much of this decrease occurred between 1990 and 1995 - linked to a decline in emissions from manufacturing and the iron and steel industry over this time period. There has been a further smaller decrease between 2008 and 2009, coinciding with the recession. Figures have then been more level in recent years, albeit with small fluctuations in emissions from this sector since 2009. There was another decrease (0.5 MtCO ₂e; 5.9 per cent) in emissions in this sector between 2013 and 2014. This has been driven a number of factors, which include a reduction in emissions from combustion in the petrochemicals industry, and from the space heating of offices, which is partly linked to external temperatures. There was also a smaller drop in emissions from pulp and paper making.

Agriculture and Related Land Use

This sector has seen a 3.6 MtCO ₂e (25.0 per cent) fall in net emissions between 1990 and 2014. This has been driven by a fall in emissions of carbon dioxide (Chart B9), methane (Chart B10) and nitrous oxide (Chart B11).

The fall in carbon dioxide emissions from the agriculture and related land use sector has partly been due to the effects of historic land use changes. For instance, there have been changes in the area of land being converted from other uses to cropland. Between 1990 to 2014, the rate at which land has been converted to cropland has fallen, with more land now remaining as cropland and not being changed to other uses. The process of land being converted to cropland releases carbon dioxide. Over time, this process gradually emits less carbon dioxide. There has also been an increase in the net sequestration of carbon dioxide from grassland.

Methane emissions from agriculture have fallen from 1990 to 2014 due to a decline in cattle and sheep numbers - with a corresponding fall in emissions from enteric fermentation and animal wastes. Nitrous oxide emissions have also fallen over this time period, albeit with a slight increase in recent years. The overall decrease in emissions between 1990 and 2014 could be due to improvements in practices on agricultural soils and a decline in livestock numbers.

Between 2013 and 2014, there was a 0.2 MtCO ₂e (1.7 per cent) decrease in net emissions of overall greenhouse gases from this sector. This is due to a continued reduction in emissions from land being converted to cropland and an increase in the net greenhouse gas sink from grasslands. There has been a very slight (around 1 per cent) increase in emissions from agricultural soils in the latest year - despite a general downward trend over time. This could be due to increased use of nitrogenous fertilisers.

Forestry

This sector has seen a 1.4 MtCO ₂e (16.1 per cent) increase in its carbon sink between 1990 and 2014. The majority of the sink arises from the large area of conifer plantations in Scotland, which is subject to forest management such as thinning and harvesting. The increase in the carbon sink is due to an increase in the area of forest land over this time period. The area of land being converted to forest from other land uses has been decreasing over time, with more land remaining as forestry.

Carbon sequestration from forestry increased between 1990 and 1999. However, over the last 40 years the rate of afforestation has decreased and with conifer plantations established in the mid-20th century reaching their planned rotation age now being felled and replanted. This has resulted in the size of the annual sink remaining relatively constant from 1999 onwards, albeit with a slight reduction in sequestration in recent years. Between 2013 and 2014, there was a small reduction (0.1 MtCO ₂e) in the size of the carbon sink from forestry.

Transport (Including International Aviation and Shipping)

Between 1990 and 2014, emissions from transport (including international aviation and shipping) fell slightly. Chart B2 shows that emissions rose to a peak in 2007, before falling slightly. This slight fall has been largely caused by changes in road transport emissions. As well as reflecting improvements in car energy efficiency, road transport emissions have been affected by changes in the make-up of the passenger car fleet, with an increase in more fuel efficient diesel engines compared with petrol vehicles. Up to 2007, there was a large increase in car vehicle kilometres travelled. There was a slight drop in car vehicle kilometres travelled in the years after 2007, but this value has increased by 2014 to around 2007 levels.

Breaking transport emissions down further, between 1990 and 2014, there was a 0.8 per cent decrease in transport emissions (excluding international aviation and shipping) and a 10.9 per cent decrease in emissions from international aviation and shipping. International aviation emissions have more than doubled between 1990 and 2014 (from 0.5 MtCO ₂e to 1.2 MtCO ₂e). This reflects the growth in aviation and the increase in international routes at airports. Emissions from international shipping have fallen by 46.8 per cent between 1990 and 2014 (from 2.0 MtCO ₂e to 1.1 MtCO ₂e). This is primarily due to a decrease in Scotland's port freight movements.

Between 2013 and 2014, there was a 0.5 per cent increase in emissions from transport (excluding international aviation and shipping). There has been an increase in emissions from light good vehicles (0.06 MtCO ₂e; 4.1 per cent) between 2013 and 2014. There has also been a slight increase in emissions from cars between 2013 and 2014 (0.04 MtCO ₂e; 0.7 per cent), which is linked to an increase in car vehicle kilometres.

Between 2013 and 2014, there was a 5.5 per cent increase in emissions from international aviation and a 10.2 per cent decrease in international shipping. It should be noted that the data series for international shipping is particularly volatile.

Public Sector Buildings

This sector contributes a small proportion of Scotland's net greenhouse gas emissions. The main source of emissions from this sector is the use of natural gas for heating public buildings. There was a 0.6 MtCO ₂e (36.2 per cent) fall in emissions from public sector buildings between 1990 and 2014. This has been largely driven by a reduction in the use of oil and coal for space heating. Between 2013 and 2014, there has been a 0.2 MtCO ₂e (14.2 per cent) fall in emissions from this sector, and this has been partly linked to less space heating for buildings because of the warmer external temperatures in 2014.

Development Emissions

This sector captures net emissions from settlements and from land converted to settlements. It accounts for only a small proportion of Scotland's net greenhouse gas emissions. There was a 0.3 MtCO ₂e (13.8 per cent) decrease in development emissions between 1990 and 2014. Between 2013 and 2014, there was very little change in emissions from this sector.

Emissions by type of gas

Chart B8 shows the trends in emissions, broken down by gas from 1990 to 2014.

Chart B8. Scottish Greenhouse Gas Emissions, by Gas, 1990-2014. Values in MtCO ₂e

Main Points

• Carbon dioxide is by far the largest contributor of Scottish greenhouse gas emissions in all years (73.7 per cent of all emissions in 2014) and is the most volatile series of all gases - largely driven by changes in energy supply emissions and to a lesser extent, emissions from the residential and business and industrial process sectors.
• Methane in the second most common greenhouse gas in 2014 (16.1 per cent of all net emissions) followed by nitrous oxide (7.0 per cent) and F-gases making up the remainder (3.2 per cent).
• Methane has seen the largest percentage reduction from 1990 to 2014 (57.5 per cent), which have been largely driven by a reduction in waste management emissions. There have also been percentage reductions for both carbon dioxide (37.6 per cent) and nitrous oxide (21.3 per cent). Emissions from fluorinated gases have shown a 7-fold increase from 1990 to 2014 and this increase is driven by the introduction of hydrofluourocarbons ( HFCs) from 1995 onwards. These HFCs replace chlorofluorocarbons ( CFCs) which were banned by the Montreal Protocol due to their impact on the ozone layer.

Charts B9 to B12 present results on individual gases broken down by main Scottish Government sectors over time. Table B3 contains figures on all greenhouse gas emissions across the time series. Chart B9 shows how carbon dioxide emissions have changed from 1990 to 2014.

Carbon Dioxide ( CO ₂)

Chart B9. Carbon Dioxide ( CO ₂) Emissions by Scottish Government Sector, 1990 to 2014. Values in MtCO ₂e

Main Points

• Chart B9 shows that energy supply is the key source of carbon dioxide emissions in all years between 1990 and 2014. Transport (including international aviation and shipping) is the next most common source of carbon dioxide emissions in all years apart from 1990, and is only 0.5 MtCO ₂e lower than energy supply emissions in 2014.
• Much of the decrease in carbon dioxide emissions between 1990 and 2014 has been driven by falls in the energy supply sector across the time period and in business and industrial processes between 1990 and 1995. Carbon dioxide emissions from the energy supply sector have been quite volatile, with the highest emissions occurring between 1995 and 2003, and a spike in 2006, related to a greater use of coal in that year.
• The agriculture and related land use sector has also seen a fall in net emissions of carbon dioxide - largely due to changes in land uses
• Forestry has been a net sink of carbon dioxide consistently between 1990 and 2014.

Methane ( CH ₄)

Chart B10. Methane ( CH ₄) Emissions by Scottish Government Sector, 1990 to 2014. Values in MtCO ₂e

Main Points

• Methane emissions from waste management have fallen from 9.7 MtCO ₂e in 1990 to 2.2 MtCO ₂e in 2014 (a 77.9 per cent reduction). This is due to the progressive introduction of landfill gas being captured and used for energy. There could also be other factors which contribute to this reduction, such as improvements in the standards of landfill and changes to the types of waste going to landfill.
• Methane emissions in the agriculture and related land use sector have fallen from 5.6 MtCO ₂e in 1990 to 4.7 MtCO ₂e in 2014 - a 15.3 per cent fall over this time period. This reduction is partly linked to a fall in livestock numbers.
• In the Energy Supply sector, methane emissions have fallen from 2.0 MtCO ₂e in 1990 to 0.5 MtCO ₂e in 2014, largely due to reductions in emissions from sources such as coal mining.

Nitrous Oxide ( N ₂O)

Chart B11. Nitrous Oxide ( N ₂O) Emissions by Scottish Government Sector, 1990 to 2014. Values in MtCO ₂e

Main Points

• The Agriculture and related land use sector is by far the main contributor to emissions of nitrous oxide. These are largely produced by agricultural practices on soils, and to a lesser extent by animal manures. Emissions of nitrous oxide in this sector have fallen from 3.2 MtCO ₂e in 1990 to 2.7 MtCO ₂e in 2014. This has been due to improvements in practices in agricultural soils and a decline in livestock numbers. There has been a very slight (around 1 per cent) increase in emissions from agricultural soils in 2014. This could be due to an increased use of nitrogenous fertilisers.
• Emissions of nitrous oxide in the business and industrial process sector have fallen from 0.5 MtCO ₂e in 1990 to 0.1 MtCO ₂e in 2014.

Fluorinated gases (F-gases)

Chart B12. F-gas Emissions by Scottish Government Sector, 1990 to 2014. Values in MtCO ₂e

Main Points

• F gases are the most potent greenhouse gases with high global warming potentials but they are emitted in very small quantities. As a result, they contribute less to global warming than the other greenhouse gases in Scotland.
• There has been a sharp increase in F gas emissions from business and industrial processes between 1990 and 2014 (from 0.2 MtCO ₂e in 1990 to 1.3 MtCO ₂e in 2014). This is because F gases were introduced to replace chlorofluorocarbons ( CFCs), which were used in appliances such as industrial air conditioning units. CFCs were banned under the Montreal Protocol, as they were contributing to the depletion of the ozone layer.
• F gas emissions in the residential sector are caused by the use of aerosols and asthma inhalers, and represent between 0.15 and 0.20 MtCO ₂e in the years between 1998 and 2014.

Table B2. Greenhouse Gas Emissions in Scotland by source sector: 1990 to 2014. Values in MtCO ₂e

Source Sector	Baseline Period	1990	1995	2000	2005	2006	2007	2008	2009	2010	2011	2012	2013	2014	Change between 1990 and 2014 (in MtCO 2e)	% change between 1990 and 2014
Total greenhouse gas emissions	77.3	77.2	77.6	74.7	65.9	69.0	64.2	61.9	57.2	59.0	52.3	52.7	51.1	46.7	-30.5	-39.5%
Energy Supply	22.8	22.8	26.8	26.3	20.7	24.7	21.4	20.2	18.8	20.9	17.0	17.5	16.0	13.8	-8.9	-39.2%
Transport (including International Aviation and Shipping)	13.3	13.3	13.3	13.4	14.2	14.8	14.9	14.6	13.9	13.4	13.2	13.1	12.9	12.9	-0.4	-2.8%
Excluding IA&S	10.7	10.7	10.7	11.1	11.6	11.8	12.0	11.5	11.0	10.9	10.6	10.7	10.6	10.6	-0.1	-0.8%
International Aviation and Shipping (IA&S)	2.6	2.6	2.6	2.4	2.6	3.0	3.0	3.1	2.9	2.5	2.6	2.4	2.3	2.3	-0.3	-10.9%
Agriculture and Related land Use	14.2	14.2	14.5	14.0	12.6	12.2	11.9	11.4	11.4	11.3	10.9	10.7	10.9	10.7	-3.6	-25.0%
Business and Industrial process	14.3	14.3	11.0	11.2	11.1	10.8	10.4	10.5	9.2	9.3	9.1	8.9	9.2	8.7	-5.7	-39.6%
Residential	8.0	7.9	7.8	7.8	7.6	7.4	7.2	7.4	7.1	8.0	6.2	7.0	7.0	5.9	-2.1	-26.0%
Waste Management	9.8	9.8	10.1	9.1	6.9	6.5	5.9	5.3	4.5	3.8	3.5	3.1	2.6	2.2	-7.6	-77.3%
Other sources	3.5	3.5	3.6	3.4	3.2	3.0	2.9	3.1	2.9	2.9	2.9	2.8	2.8	2.7	-0.9	-24.5%
Development	1.8	1.8	1.8	1.8	1.7	1.7	1.7	1.6	1.6	1.6	1.6	1.6	1.6	1.6	-0.3	-13.8%
Public Sector Buildings	1.7	1.7	1.8	1.6	1.5	1.4	1.3	1.5	1.2	1.3	1.2	1.2	1.3	1.1	-0.6	-36.2%
Forestry [9]	-8.8	-8.8	-9.5	-10.4	-10.5	-10.5	-10.5	-10.5	-10.5	-10.5	-10.5	-10.4	-10.3	-10.2	-1.4	16.1%

Table B3. Scottish Greenhouse Gases, by gas, 1990 to 2014. Values in MtCO ₂e

	Baseline Period	1990	1995	2000	2005	2006	2007	2008	2009	2010	2011	2012	2013	2014	Change from 1990 to 2014 (in MtCO 2e)	% Change from 1990 to 2014	Share of Greenhouse Gases, 2014
Total Greenhouse Gases	77.3	77.2	77.6	74.7	65.9	69.0	64.2	61.9	57.2	59.0	52.3	52.7	51.1	46.7	-30.5	-39.5%	100.0%
Carbon dioxide ( CO 2)	55.1	55.1	55.8	54.5	48.4	52.0	47.9	46.5	42.6	45.1	38.8	39.7	38.5	34.4	-20.7	-37.6%	73.7%
Methane ( CH 4)	17.7	17.7	17.6	15.7	12.9	12.3	11.7	10.8	9.9	9.2	8.9	8.4	7.9	7.5	-10.2	-57.5%	16.1%
Nitrous oxide ( N 2O)	4.2	4.2	3.8	3.8	3.4	3.4	3.3	3.2	3.3	3.3	3.2	3.2	3.3	3.3	-0.9	-21.3%	7.0%
* F gases	0.3	0.2	0.3	0.8	1.2	1.3	1.3	1.3	1.4	1.5	1.3	1.4	1.4	1.5	1.3	703.7%	3.2%
of which HFCs	0.1	0.0	0.1	0.5	1.0	1.1	1.2	1.2	1.3	1.3	1.2	1.3	1.3	1.3	1.3	62317.8%	2.8%
PFCs	0.1	0.1	0.1	0.2	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.0	3.4%	0.3%
SF 6	0.0	0.0	0.0	0.1	0.1	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	-34.3%	0.1%
NF 3	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	37.2%	0.0%

* Note on F-gases:

HFCs are hydrofluorocarbons

PFCs are perfluorocarbons

SF ₆ is sulphur hexafluoride

NF ₃ is nitrogen trifluoride