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Executive Summary

Climate change & greenhouse gas inventory

Greenhouse gases trap warmth from the sun and make life on Earth possible. However, over the previous 50 to 100 years, the concentration of the greenhouse gases carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in the atmosphere has been increasing. The increased concentration produces an 'enhanced greenhouse effect' that causes the atmosphere to trap more heat and the climate to change. The climate changes ahead of us are expected to be much larger and happen more quickly than any recent natural changes.

The long-term objective of the United Nations Framework Convention on Climate Change (UNFCCC ) is to stabilise greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. All countries that ratify the UNFCCC are required to address climate change through national or regional programmes, prepare for adaptation to the impacts of climate change and monitor emissions trends via greenhouse gas inventories. In May 1992, developed countries agreed to non-binding targets to reduce greenhouse gas emissions to 1990 levels by 2000.

Only a few countries made appreciable progress towards achieving their targets. The international community recognised that the UNFCCC alone was not enough to ensure greenhouse gas levels would be reduced to safe levels, and that more urgent action was needed. After two and a half years of negotiations, the Kyoto Protocol was adopted in 1997. The Kyoto Protocol commits Annex I Parties that ratify the Protocol to individual, legally-binding targets to limit or reduce their greenhouse gas emissions. New Zealand ratified the Kyoto Protocol on 19 December 2002 with a target of reducing its emissions to the level they were in 1990. The Protocol came into force on 16 February 2005.

The development and publication of an annual inventory of all human-induced emissions and removals of greenhouse gases not controlled by the Montreal Protocol is part of New Zealand's obligations under the UNFCCC and the Kyoto Protocol. The inventory is the tool for measuring New Zealand's progress against these obligations. The inventory totals emissions and removals of the gases CO2, CH4, N2O, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6) from six sectors: energy, industrial processes, solvents, agriculture, 'land-use, land-use change and forestry' (LULUCF) and waste.

National trends in New Zealand's emissions and removals

In 1990, New Zealand's total greenhouse gas emissions were equivalent to 61,525.43Gg of CO2. In 2003, total greenhouse gas emissions were 75,345.29Gg CO2 equivalent equating to a 22.5% rise since 1990 (Figure 1.1). Net removals of CO2 through forest sinks increased from 21,366.19Gg CO2 in 1990 to 22,861.60Gg CO2 in 2003.

Figure 1.1 New Zealand's total greenhouse gas emissions 1990-2003

Year Gg CO2 equivalent
1990 61,525.43
1991 62,033.02
1992 63,552.73
1993 63,457.24
1994 63,768.75
1995 64,277.82
1996 65,665.38
1997 67,876.39
1998 66,732.62
1999 68,535.28
2000 69,695.65
2001 72,623.27
2002 73,233.20
2003 75,345.29

There have also been changes in the relative amounts of the different greenhouse gases emitted. Whereas CH4 and CO2 contributed equally to New Zealand's emissions in 1990, CO2 is now the major greenhouse gas in New Zealand's emissions profile (Table 1.1). This is attributed to increased growth in the energy sector compared to the agriculture sector.

Table 1.1 Emissions of greenhouse gases in 1990 and 2003

Greenhouse gas emissions

Gg CO2 equivalent

Change from 1990 (%)

1990

2003

Net CO2 emissions / removals

3,944.36

11,833.84

200.02

CO2 emissions (without LULUCF)

25,314.81

34,699.55

37.07

CH4

25,283.98

26,644.97

5.38

N2O

10,398.71

13,499.53

29.82

HFCs

0.00

403.96

NA

PFCs

515.60

84.90

-83.53

SF6

12.33

12.38

0.39

Total emissions without CO2 from LULUCF

61,525.43

75,345.29

22.5

Source and sink category emission estimates and trends

New Zealand is unusual amongst developed nations in that 49.4% of total emissions in 2003 were produced by the agriculture sector (Figure 1.2). The agricultural emissions are predominantly CH4 emissions from ruminant farm animals and N2O emissions from animal excreta and nitrogenous fertiliser use. The current level of emissions from the agriculture sector is 15.6% above the 1990 level (Table 1.2).

The energy sector is the other large component of New Zealand's emissions profile comprising 42.9% of total emissions in 2003. Emissions from the energy sector are now 37.0% above the 1990 level (Table 1.2). The growth in energy emissions is primarily from road transport (an increase of 58.4%) and electricity generation (an increase of 83.3%). The large increase in electricity generation is because 2003 was a dryer year than usual, resulting in less hydro-electric generation and a greater reliance on coal.

In contrast to most other developed nations, emissions from the industrial processes and waste sectors are a much smaller component of New Zealand's emissions, comprising only 5.3% and 2.3% respectively of all greenhouse gas emissions in 2003. Emissions from the waste sector are now 29.3% below the 1990 baseline with the majority of the reduction occurring from improvements in solid waste disposal. New Zealand's relatively small manufacturing base means that solvent use is lower than in many other countries.

The LULUCF sector represents the major sink for New Zealand, removing 30.3% of all greenhouse gas emissions in 2003. Net removals in 2003 are 7.0% above net removals in 1990. Variations in planting rates and the impact of harvest regimes affect the size of this sink from year to year.

Figure 1.2 New Zealand's sectoral emissions in 2003 (all figures Gg CO2 equivalent)

 

Sector Gg CO2 equivalent Percent of total
Energy 32,320.92 42.9
Industrial processes 4,014.19 5.3
Solvents and other products 48.36 0.1
Agriculture 37,203.24 49.4
Waste 1,754.48 2.3

Table 1.2 Sectoral emissions of greenhouse gases in 1990 and 2003

Sector

Gg CO2 equivalent

Change from 1990 (%)

1990

2003

Energy

23,594.11

32,320.92

35.7

Industrial processes

3,211.70

4,014.19

25.0

Solvent and other products

41.54

48.36

16.4

Agriculture

32,193.76

37,203.24

15.6

Land-use change and forestry

-21,366.19

-22,861.60

7.0

Waste

2,480.06

1,754.48

-29.3