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This document provides an overview of "New Zealand's Greenhouse Gas Inventory 1990 - 2006". The overview provides key information in an accessible form. The full inventory report is required under the United Nations Framework Convention on Climate Change and the Kyoto Protocol.
Greenhouse gases in the Earth’s atmosphere trap warmth from the sun and make life as we know it possible. However, since the industrial revolution (about 1750) there has been a global increase in the atmospheric concentration of greenhouse gases such as carbon dioxide, methane and nitrous oxide1. This increase is attributed to human activities, particularly the burning of fossil fuels and land-use change.
In 2007, the Intergovernmental Panel on Climate Change (IPCC) concluded that most of the increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations(see footnote 1). The IPCC has predicted that continued greenhouse gas emissions at, or above, current rates would cause further warming and induce many changes in the global climate system during the 21st century.
This overview presents a summary of the latest information on New Zealand’s greenhouse gas emissions and removals. The information is from the most recent national inventory report under the United Nations Framework Convention on Climate Change (New Zealand’s Greenhouse Gas Inventory 1990–2006). This latest inventory contains information from 1990 through to the current inventory year of 2006. Each inventory report is 15 months in arrears allowing time for data to be collected and analysed.
Greenhouse gas estimates are based on international guidance established by the IPCC and follow an internationally agreed reporting format that groups emissions and removals into six sectors:
Energy (including transport)
Solvent and other product use
Land use, land-use change and forestry.
The greenhouse gases estimated in the inventory include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulphur hexafluoride (SF6), perfluorocarbons (PFCs), and hydrofluorocarbons (HFCs). To compare the warming effect of different gases, all emissions are converted to carbon dioxide equivalents (CO2-e). This is achieved by multiplying emissions by the appropriate global warming potential.
Table 1: Units and common global warming potentials
Standard metric prefixes used in this overview are:
kilo (k) = 103 (one thousand)
mega (M) = 106 (one million)
giga (G )= 109 (one thousand million)
Emissions are expressed in megatonnes (Mt) in this overview. Numbers are generally rounded to one decimal place (this can lead to rounding errors in some figures)
1 megatonne (Mt) = 1,000,000 tonnes = 1,000 Gg
Common global warming potentials
The global warming potential is an index, representing the combined effect of the differing times greenhouse gases remain in the atmosphere and their relative effectiveness in absorbing thermal infrared radiation (see footnote 1).
CO2 = 1
CH4 = 21
N2O = 310
SF6 = 23,900
The United Nations Framework Convention on Climate Change (the Climate Change Convention) is an international agreement which addresses climate change. All countries that ratify the Climate Change Convention are required to tackle climate change through national or regional programmes. The long-term objective of the Climate Change Convention is to “stabilise greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system”. Developed countries agreed to non-binding commitments to reduce greenhouse gas emissions to 1990 levels by the year 2000.
Developed countries that are signatories to the Climate Change Convention, including New Zealand, are required to submit an annual greenhouse gas inventory. Inventory reporting covers all human-induced emissions and removals of greenhouse gases not controlled by the Kyoto Protocol.
Only a few countries made appreciable progress towards achieving their commitment to reduce emissions under the Climate Change Convention. The international community recognised that the provisions of the Climate Change Convention alone were not enough to ensure greenhouse gases would be reduced to safe levels and that more urgent action was required. After two and a half years of negotiations the Kyoto Protocol was adopted in December 1997. New Zealand ratified the Protocol on 19 December 2002. The Kyoto Protocol came into force on 16 February 2005.
The goal of the Kyoto Protocol is to reduce aggregate emissions of six greenhouse gases from Annex 1 Parties (developed countries) by at least 5 per cent below 1990 levels in the first commitment period (2008–2012). New Zealand’s commitment is to ensure that the average emissions over the first commitment period of the Kyoto Protocol (2008–2012) are less than or equal to emissions in 1990 as reported in New Zealand’s Initial Report under the Kyoto Protocol2. Parties can use the Kyoto Protocol flexibility mechanisms, for example carbon trading, to help meet this commitment.
Under Article 7.1 of the Kyoto Protocol, New Zealand is required to include supplementary information with the inventory. The supplementary information becomes mandatory for the 1990–2008 inventory submitted in 2010. However, in order to fully participate in Kyoto mechanisms, for example carbon trading, a Party must submit a complete inventory under the Climate Change Convention for 2007 and continue to do so for all years of the commitment period.
In the 2008 inventory submissions, New Zealand has reported supplementary information under the Kyoto Protocol in Annex 8. Information on transactions of transferred and/or acquired units under Kyoto mechanisms during the 2008 calendar year will be included in the 2009 inventory submission.
1 IPCC 2007. Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt K, Tignor MB, and Miller HL (Eds). Climate Change 2007: The physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press: UK.