New Zealand’s Greenhouse Gas Inventory 1990–2006

• Executive Summary
• Chapter 1: Introduction
• Chapter 2: Trends in greenhouse gas emissions
• Chapter 3: Energy
• Chapter 4: Industrial processes
• Chapter 5: Solvent and other product use
• Chapter 6: Agriculture
• Chapter 7: Land use, land-use change and forestry (LULUCF)
• Chapter 8: Waste
• Chapter 9: Other
• Chapter 10: Recalculations and improvements
• References
• Annex 1: Key categories
• Annex 2: Methodology and data collection for estimating emissions from fossil fuel combustion
• Annex 3: Detailed methodological information for other sectors
• Annex 4: CO₂ reference approach and comparison with sectoral approach, and relevant information on the national energy balance
• Annex 5: Assessment of completeness and (potential) sources and sinks of greenhouse gas emissions and removals excluded
• Annex 6: Quality assurance and quality control
• Annex 7: Uncertainty analysis (Table 6.1 of the IPCC Good Practice Guidance)
• Annex 8: Supplementary information under Article 7.1 of the Kyoto Protocol

Chapter 2: Trends in greenhouse gas emissions

2.1 Emission trends for aggregated greenhouse gas emissions

In 1990, New Zealand’s total greenhouse gas emissions were equivalent to 61,947.9 Gg carbon dioxide equivalent (CO₂-e). In 2006, total greenhouse gas emissions had increased by 15,920.2 Gg CO₂-e (25.7 per cent) to 77,868.1 Gg CO₂-e (Figure 2.1.1). Between 1990 and 2006, the average annual growth in overall emissions was 1.5 per cent per year.

New Zealand’s total emissions trend is different to many other countries. Instead of a predictable increase or decline in emissions, the trend for New Zealand consists of year to year fluctuations (Figure 2.1.1). These fluctuations are largely due to the change in proportion of non-renewable energy used in electricity and heat production affecting CO₂ emissions (Figure 3.2.2). This is further explained in section 3.2.1.1.

2.2 Emission trends by gas

Inventory reporting under the Climate Change Convention covers six direct greenhouse gases, carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), sulphur hexafluoride (SF₆), perfluorocarbons (PFCs) and hydrofluorocarbons (HFCs). Figure 2.2.1 shows the change in each direct greenhouse gas between 1990 and 2006. Trends in CO₂, CH₄ and N₂O emissions over the period 1990–2006 are shown in Figure 2.2.2. In accordance with the Climate Change Convention reporting guidelines (UNFCCC, 2006), indirect greenhouse gases are included in inventory reporting but not in the national emission total. These indirect gases include carbon monoxide (CO), sulphur dioxide (SO₂), oxides of nitrogen (NO_X), and non-methane volatile organic compounds (NMVOCs).

Removals of carbon dioxide from the atmosphere are reported in the LULUCF sector.

• Carbon dioxide contributed the largest share of all 2006 emissions at 36,388.0 Gg CO₂-e (46.7 per cent). Carbon dioxide emissions increased by 11,005.8 Gg CO₂-e (43.3 per cent) from the 1990 level of 25,382.2 Gg CO₂-e.

• Methane contributed 27,499.3 Gg CO₂-e (35.3 per cent) of total emissions in 2006. Methane emissions have grown by 2,013.7 Gg CO₂-e (7.9 per cent) from the 1990 level of 25,485.6 Gg CO₂-e.

• Nitrous oxide contributed 13,283.7 Gg CO₂-e (17.1 per cent) of emissions in 2006. Emissions have increased by 2,857.7 Gg CO₂-e (27.4 per cent) from the 1990 level of 10,426.0 Gg CO₂-e.

• Perfluorocarbons, SF₆ and HFCs contributed the remaining 697.1 Gg CO₂-e (0.9 per cent) of emissions in 2006.

• Emissions of PFCs have decreased by 550.8 Gg CO₂-e (85.8 per cent) from the 641.7 Gg CO₂-e in 1990, to 90.9 Gg CO₂-e in 2006.

• Emissions of SF₆ have grown by 0.9 Gg CO₂-e (7.4 per cent), from the 1990 level of 12.3 Gg CO₂-e to the 2006 level of 13.2 Gg CO₂-e.

• In 1990, no HFCs were used in New Zealand. In 2006, 592.9 Gg CO₂-e of HFC emissions were produced.

The growth in CO₂ represents the increased emissions from the energy sector particularly in road transport and energy generation. The growth in N₂O is from increased emissions from animal excreta and the increased use of nitrogenous fertilisers in the agriculture sector. The amount of nitrogenous fertilisers used in New Zealand has increased six-fold since 1990.

Although the contribution of the other gases (HFCs, PFCs and SF₆) in the inventory is around 1 per cent of the total emissions, these gases have also undergone large relative changes between 1990 and 2006. Emissions of PFCs have decreased due to improvements in the aluminium smelting process. HFC emissions have increased because of the use of HFCs as a substitute for chlorofluorocarbons (CFCs) phased out under the Montreal Protocol. No emissions of HFCs occurred in 1990 therefore no percentage has been shown in Figure 2.2.1 and Table 2.2.1.

Table 2.2.1 Emissions of greenhouse gases in 1990 and 2006

Greenhouse gas emissions	Gg CO2-equivalent19902006		Change from 1990 (Gg CO2 -equivalent)	Change from 1990 (%)
CO2 (excluding LULUCF)	25,382.2	36,388.0	11,005.7	43.3
CH4 (excluding LULUCF)	25,485.6	27,499.3	2,013.7	7.9
N2O (excluding LULUCF)	10,426.0	13,283.7	2,857.7	27.4
HFCs	0.0	593.0	593.0	NA
PFCs	641.7	90.9	–550.8	–85.8
SF6	12.3	13.2	0.9	7.4
Total	61,947.9	77,868.1	15,920.2	25.7

2.3 Emission trends by source

• The agriculture sector is the largest source of emissions, contributing 37,667.6 Gg CO₂-e (48.4 per cent) of total emissions in 2006 (Figure 2.3.1 and Table 2.3.1). Consequently, New Zealand has a unique emissions profile. In other developed countries, agricultural emissions typically are around 12 per cent of national emissions. In 2006, agricultural emissions have increased 5,168.8 Gg CO₂-e (15.9 per cent) from the 1990 level of 32,498.9 Gg CO₂-e. The agriculture sector contributed 12,801.9 Gg CO₂-e (96.3 per cent) of New Zealand’s total nitrous oxide emissions and 24,865.7Gg CO₂-e (90.3 per cent) of total methane emissions in 2006.

• The energy sector was the source of 34,069.3 Gg CO₂-e (43.8 per cent) of all emissions in 2006. In 2006, energy emissions have increased 10,570.2 Gg CO₂-e (45.0 per cent) from the 1990 level of 23,499.1 Gg CO₂-e. This growth in emissions is primarily from electricity generation and heat production and transport.

• The industrial processes sector accounts for 4,233.1 Gg CO₂-e (5.4 per cent) of total emissions in 2006. Emissions from the industrial processes sector have increased 830.4 Gg CO₂-e (24.4 per cent) from the 1990 level of 3,402.7 Gg CO₂-e. The increase is mainly growth in emissions from metal production and consumption of hydrofluorocarbons.

• The solvents and other products sector is a minor contributor to New Zealand’s total direct greenhouse gas emissions, being responsible for 40.3 Gg CO₂-e (0.05 per cent) of total emissions.

• The waste sector accounts for 1,857.8 Gg CO₂-e (2.4 per cent) of total emissions in 2006. Emissions from the waste sector have decreased 647.8 Gg CO₂-e (25.9 per cent) from a 1990 level of 2,505.7 Gg CO₂-e. This decrease is due to initiatives to improve solid waste management practices in New Zealand.

• Under the LULUCF sector, removals are estimated to be 22,749.3 Gg CO₂-e (29.2 per cent) of national emissions in 2006. LULUCF removals have increased 2,241.6 Gg CO₂-e (10.9 per cent) from the 1990 level of 20,507.7 Gg CO₂-e. LULUCF removals fluctuate with the planting and harvesting of New Zealand’s planted forest.

Table 2.3.1 Sectoral emissions of greenhouse gases in 1990 and 2006

Sector	Gg CO2-equivalent19902006		Change from 1990 (Gg CO2-equivalent)	Change from 1990 (%)
Energy	23,499.1	34,069.3	10,570.2	45.0
Industrial processes	3,402.7	4,233.1	830.4	24.4
Solvent and other product	41.5	40.3	–1.2	–3.0
Agriculture	32,498.9	37,667.6	5,168.8	15.9
Waste	2,505.7	1,857.8	–647.8	–25.9
Total (excluding LULUCF)	61,947.9	77,868.1	15,920.2	25.7
Land-use change and forestry (including CH4 & N2O)	–20,507.7	-22,749.3	–2,241.6	10.9
Net Total (including LULUCF)	41,440.2	55,118.8	13,678.7	33.0

2.4 Emission trends for indirect greenhouse gases and SO₂

The indirect greenhouse gases SO₂, CO, NO_x and NMVOC are also reported in the inventory. Emissions of these gases in 1990 and 2006 are shown in Table 2.4.1. There have been increases in the emissions of all gases. Indirect greenhouse gases are not included in New Zealand’s total greenhouse gas emissions.

Table 2.4.1 Emissions of indirect greenhouse gases and SO₂ in 1990 and 2006

Gas	Gg of gas(es)		Change from 1990 (Gg)	Change from 1990 (%)
	1990	2006
NOx	107.3	167.5	60.2	56.1
CO	526.1	650.8	124.7	23.7
NMVOC	133.7	168.5	34.8	26.0
SO2	54.3	81.3	27	49.7
Total	821.4	1,068.1	246.7	30.0

Emissions of CO and NO_x are largely from the energy sector. The energy sector produced 87.6 per cent of total CO emissions in 2006. The largest single source of CO emissions was “road transportation”. Similarly, the energy sector was the largest source of NO_x emissions (98 per cent), with “road transportation” dominating. Other large sources of NO_x emissions are from “manufacturing industries and construction” and “energy industries”.

The energy sector was also the largest producer of NMVOCs and SO₂, producing 71.2 per cent of NMVOC emissions in 2006. Emissions from “road transportation” comprised 63.1 per cent of total NMVOC emissions. Other major sources of NMVOC are in the solvent and other product use sector (20.3 per cent) and the industrial processes sector (8.5 per cent).

Emissions of SO₂ from the energy sector comprised 86.2 per cent of total SO₂ emissions. The “energy industries” category contributed 28.8 per cent, “manufacturing industries and construction” 25.8 per cent and “transport” 15.2 per cent of total SO₂ emissions. The other source of SO₂ was from the industrial processes sector.

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