New Zealand's Greenhouse Gas Inventory

This page contains information about New Zealand's Greenhouse Gas Inventory. It includes information about the data, the sectors and gases covered, quality and best practice reviews, and how the inventory differs from the New Zealand Emissions Trading Scheme and the net position estimate.

Publication link 

New Zealand's greenhouse gas inventory (includes links to supporting tables, files and the Snapshot)

What the inventory contains

New Zealand's Greenhouse Gas inventory is an annual report of all human-induced emissions and removals of greenhouse gases in New Zealand. The inventory is produced each year as part of New Zealand’s obligations under the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol. The next publication of New Zealand’s Greenhouse Gas Inventory is planned for 10th of April 2015.

See inventories produced by all Annex I Parties from 2003 at National inventory submissions 2014  [UNFCCC website]

Responsibility for the inventory

The Ministry for the Environment (the Ministry) as the ‘Inventory Agency’ is responsible for submitting the greenhouse gas inventory under the UNFCCC every year by 15 April. The Ministry is also New Zealand’s designated single national entity for the greenhouse gas inventory under the Kyoto Protocol.

The Ministry works closely with the Ministry of Business, Innovation and Employment, the Ministry for Primary Industries and the Environmental Protection Authority to compile the data. Many of the values used in the inventory are also derived from data collated by Statistics New Zealand. The Ministry of Foreign Affairs and Trade provides the information on the minimisation of adverse impacts, which is also included in the inventory (currently in chapter 15).

Sectors covered in the inventory

The 1990-2012 inventories reports greenhouse gas emissions and removals from six sectors:

  • agriculture
  • energy
  • industrial processes
  • land use, land-use change and forestry (LULUCF)
  • waste
  • solvent and other product use.

Under the UNFCCC, the inventory reports emissions and removals from the entire LULUCF sector. Under the Kyoto Protocol, reporting covers only the forests planted after 1989 and is limited to the activities of afforestation, reforestation and deforestation since 1 January 2008 (commonly referred to as Article 3.3 activities).

Gases covered in the inventory

The most recent inventory report published in April 2014 covered the following direct greenhouse gases: 

  • carbon dioxide (CO2)
  • methane (CH4)
  • nitrous oxide (N2O)
  • hydrofluorocarbons (HFCs)
  • perfluorocarbons (PFCs)
  • sulphur hexafluoride (SF6).

Only emissions and removals of these six direct greenhouse gases are included in the national greenhouse gas total.

The inventory also reports indirect greenhouse gases but they are not included in New Zealand’s greenhouse gas total. These gases do not have a direct warming effect, but react with other gases in the atmosphere and increase the concentration of greenhouse gases. The indirect gases are:

  • oxides of nitrogen (NOx)
  • sulphur dioxide (SO2)
  • carbon monoxide (CO)
  • non-methane volatile organic compounds (NMVOCs).

Why data is only reported to the end of 2012 when it is 2014

The international reporting guidelines govern what the inventory covers and when it is submitted. The inventory year is 15 months behind the current calendar year to give time for countries to collect data and prepare the inventory. The latest inventory, published in April 2014, contains data from 1990 to 2012 inclusive. All developed countries report using the same international guidelines.

For international guidelines see Methodology reports [Intergovernmental Panel on Climate Change website]

Changes to historic emissions data since the last inventory

Why the 1990 year gets recalculated each year

In contrast, emissions and removals for all years of the inventory are subject to change due to continuous improvement of the data and methods used to estimate emissions. Consequently, the level of total emissions in 1990 reported in the latest inventory submission is less than the 1990 level used in the initial assigned amount calculation (approximately 2.0 per cent less).

All countries face this issue and accept that although the 1990 assigned amounts are fixed for the first commitment period, inventories are required to continue to improve and this may lead to the 1990 estimate increasing or decreasing.

The Latest upate on New Zealand’s net position web page provides further detail on New Zealand’s commitment under the Kyoto Protocol.

The difference between net emissions and gross emissions

About the uncertainity in net emissions

What sinks refer to

Emission sinks refer to sectors that remove greenhouse gases from the atmosphere eg, forestry. 

Planted forests in the LULUCF sector are not Kyoto sinks

The LULUCF sector of the inventory is not the same as forest sinks or afforestation under the Kyoto Protocol. Under the UNFCCC, emissions and removals from all forests (planted and natural) for all years and all land-use (including non-forestry land-uses) are reported in the LULUCF sector. Under the Kyoto Protocol, only new forest (land that became forest after 31 December 1989) and any deforestation over the first commitment period is accounted for.

The Kyoto Protocol accounting rules for Article 3.3 activities (afforestation, reforestation and deforestation) were intended to treat emissions and removals from forestry equitably with emissions from other sectors (agriculture, energy, etc) and to incentivise change. To achieve this, countries agreed to a base year for the calculation of targets as a reference against which to estimate emissions and removals. For most countries, this base year is 1990.

Deforestation refers to a conversion of forest land to another land-use (ie, cutting down forest and not replanting in forest on a piece of land). Harvesting refers to the cutting down and replanting of forests on a piece of land. 

How harvesting is distinguished from deforestation

Areas where forests have been cut down are identified and mapped using satellite imagery. Higher resolution aerial photography and field visits are then used to distinguish whether these areas have been harvested and are being replanted, or whether the land-use has changed away from forestry (ie, the land has been deforested). The higher resolution aerial photography can detect farmed animals, new structures or newly planted trees which indicate whether or not the land is still being used for forestry.

Criteria for quality review

  • transparent – assumptions and methodologies used for an inventory should be clearly explained.
  • accurate – estimates should be accurate in that they neither over- nor under-estimate true emissions or removals and that uncertainties are reduced as far as practical.
  • complete – the inventory covers all sources and sinks as well as all gases included in the IPCC guidelines, as well as other existing relevant source/sink categories which are specific to individual countries and therefore may not be included in the IPCC guidelines.
  • consistent – the inventory should be consistent with inventories of other years (eg, the same methodologies are used and consistent data sets are used to estimate emissions or removals from sources or sinks). Sometimes an inventory using different methodologies for different years can be considered to be consistent if it has been recalculated in a transparent manner in accordance with the IPCC guidelines.
  • comparable – estimates of emissions and removals reported in inventories should be comparable among countries. For this purpose, countries should use the methodologies and formats agreed by the Conference of the Parties [Climate Change Information website] for estimating and reporting inventories.

The inventory is also a Tier 1 statistic [Statisphere website] under the New Zealand Official Statistics System, which means it is one of the most important publically available statistics for understanding how well New Zealand is performing.

See Inventory review reports 2013 [UNFCCC website]. 

If the expert review team found that New Zealand’s inventory did not meet the international criteria (transparency, accuracy etc), New Zealand would be encouraged to make improvements to the inventory to meet each criteria.

Under the Kyoto Protocol, the expert review team has the mandate to recommend that improvements are made during the review period. New Zealand would be provided with opportunities to correct any problems.

If New Zealand was not able to make the corrections, the expert review team would recommend an adjustment to the emissions or removals estimate. An adjustment would result in a more conservative estimate to ensure New Zealand is not under-estimating emissions or over-estimating removals. The compliance committee of the Kyoto Protocol would decide whether to apply the adjustment. New Zealand would then either accept or reject the adjustment recommendation. In a worst case scenario New Zealand may be prohibited from international emissions trading until compliance is restored.

Disagreements are forwarded to the Kyoto Protocol Compliance Committee who would resolve the issue. This process is the same for all Parties listed in Annex B of the Kyoto Protocol (ie, those with Kyoto Protocol targets).

The New Zealand Emissions Trading Scheme (NZ ETS) is a domestic policy instrument, used to incentivise emission reductions across the New Zealand economy. It is the Government’s primary policy instrument for reducing New Zealand’s greenhouse gas emissions and meeting international emission reduction commitments. For further detail on the scheme see The New Zealand Emissions Trading Scheme [Climate Change Information website].

The difference between the net position estimate and the inventory 

The greenhouse gas inventory report is the official annual report of human-caused emissions and removals of greenhouse gases in New Zealand. The 2014 inventory submission covers emissions and removals from 1990 through to 2012.

The net position estimates the balance between New Zealand’s emissions over the first commitment period, and the Kyoto units held by the Government to account for them.

Find out more

Glossary of terms and acronyms [Climate Change Information website]