New Zealand's Greenhouse Gas Inventory

This page outlines what this annual inventory covers. It includes key findings and explanatory information for the latest inventory.  

Links to inventory publications (released May 2017) and emissions tracker

Key findings

2014 to 2015

  • New Zealand’s gross greenhouse gas emissions in 2015 were 80.2 million tonnes of carbon dioxide equivalent (Mt CO2-e). This comprises emissions from the Energy (including transport), Agriculture, Industrial Processes and Product Use (IPPU), and Waste sectors.
  • Gross emissions in 2015 were 0.1 per cent lower than emissions in 2014.
  • The Agriculture and Energy sectors were the two largest contributors to New Zealand’s gross emissions, at 47.9 per cent and 40.5 per cent respectively in 2015.
  • New Zealand’s net emissions under the UNFCCC were 56.4 Mt CO2-e in 2015. Net emissions consist of gross emissions combined with emissions and removals from the Land Use, Land-Use Change and Forestry (LULUCF) sector.

1990 to 2015

  • New Zealand’s gross emissions have increased 24.1 per cent from the year 1990.
  • The key drivers of the increase in gross emissions are:
    • carbon dioxide emissions from road transport
    • carbon dioxide emissions from chemical industry and food processing
    • methane emissions from livestock digestive systems
    • nitrous oxide emissions from fertiliser used on agricultural soils
    • fluorinated gases released from industrial, and household refrigeration and air-conditioning systems. 
  • Net emissions have increased by 63.6 per cent since 1990. This is due to the increase in gross emissions and the higher harvesting rates in planted forests in 2015 compared with 1990.

About the inventory

New Zealand's Greenhouse Gas Inventory (the inventory) is an annual report of all human-induced emissions and removals of greenhouse gases in New Zealand. It 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.

Responsibility for the inventory

The Ministry for the Environment is responsible for producing and submitting the inventory under the UNFCCC every year by 15 April. The publication of New Zealand’s Greenhouse Gas Inventory 1990-2015 was delayed until 26 May 2017 due to impacts of the Hurunui/Kaikōura earthquakes.

The Ministry is New Zealand’s designated single national entity for New Zealand's Greenhouse Gas Inventory under the Kyoto Protocol.

We work 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 supplementary information under Article 7.1 of the Kyoto Protocol.

Sectors covered in the inventory

The 1990-2015 inventory reports greenhouse gas emissions and removals from five sectors:

  • Agriculture
  • Energy
  • Industrial Processes and Product Use (IPPU)
  • Land Use, Land-Use Change and Forestry (LULUCF)
  • Waste

Under the UNFCCC, the inventory reports emissions and removals from the entire LULUCF sector. Under the Kyoto Protocol New Zealand reports only emissions and removals from forests planted or deforested since 1990 (in accordance with Article 3.3 of the Kyoto Protocol), and emissions and removals by forests not already covered under Article 3.3. This is reported under Article 3.4 (forest management). Emissions and removals from the non-forest land uses and land-use changes are not reported by New Zealand under the Kyoto Protocol.

Greenhouse gases covered in the inventory

The most recent inventory report published in May 2017 covers greenhouse gases which have direct warming effects: 

  • carbon dioxide (CO2)
  • methane (CH4)
  • nitrous oxide (N2O)
  • hydrofluorocarbons (HFCs)
  • perfluorocarbons (PFCs)
  • sulphur hexafluoride (SF6)
  • nitrogen trifluoride (NF3).

Only emissions and removals of these 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 direct greenhouse gases.

The indirect gases are:

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

The difference between net emissions and gross emissions under the UNFCCC

Gross emissions include emissions from agriculture, energy, IPPU and waste. Net emissions are made up of emissions from those four sectors and also include emissions and removals from the LULUCF sector.

Why data is only reported to the end of 2015 when it is 2017

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 and process the inventory data and prepare the submission. The latest inventory, published in May 2017 contains data from 1990 to 2015 inclusively. All Annex I countries report using the same international guidelines.

For methodological guidelines for greenhouse gas inventories see Methodology reports [Intergovernmental Panel on Climate Change website].

Changes to historic emissions data since the last inventory

The continuous improvement of inventory development and reporting is a requirement under the Kyoto Protocol and the UNFCCC. When inventory improvements are made, it is mandatory to recalculate the entire time series to ensure the consistency of emission trends. Recalculated estimates can result from any one improvement or a combination of improvements in activity data, emission factors, methodology, and emission re-allocations or when additional emission sources are identified.

Why the figures differ for net removals under the UNFCCC and the Kyoto Protocol

In any given year, New Zealand’s net removal estimate under the Kyoto Protocol accounting rules differs from the net removal estimate under UNFCCC reporting. New Zealand accounts for emissions and removals from afforestation, reforestation and deforestation, and forest management under the Kyoto Protocol. This is a subset of the land included in UNFCCC reporting, and special accounting rules are applied to this land. For instance, emissions and removals for pre-1990 forests (referred to as forest management) are only accounted for where they vary from business-as-usual levels.

How harvesting is distinguished from deforestation

Harvesting implies that the area where trees have been cut down will be (or is being) replanted while deforestation is associated with a land-use change.

Areas where forests have been cut down are identified and mapped using satellite imagery. Higher resolution aerial photography and New Zealand Emissions Trading Scheme (NZ ETS) returns are then used to distinguish whether these areas have been harvested and are being replanted, or whether the land-use has changed (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

The New Zealand inventory is compiled using internationally agreed guidelines produced by the Intergovernmental Panel on Climate Change (IPCC).

It is reviewed annually against the criteria of being:

  • 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 emissions or removals, and uncertainties should be reduced as far as practical.
  • Complete – the inventory covers all emission sources and sinks and 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 annual inventory should be internally consistent for all reported years (ie, the same methodologies are used and consistent data sets are used to estimate emissions or removals from sources or sinks).
  • Comparable – estimates of emissions and removals reported in inventories should be comparable among countries.

The inventory is a Tier 1 statistic under the New Zealand Official Statistics System. This means it is one of the most important publicly available statistics for understanding how well New Zealand is performing. Tier 1 statistics are also subject to certain principles and protocols. More on these can be found on the StatsNZ website.

International inventory review

The New Zealand inventory is reviewed annually by a team of international experts certified by the UNFCCC. Review reports are published up to 15 months after submission of the inventory, the latest review report on New Zealand’s inventory can be found on the UNFCCC website.

Net position reporting

New Zealand's inventory data are used to monitor progress towards our emissions reduction targets. Progress towards New Zealand's 2020 UNFCCC target to reduce greenhouse gas emissions to 5 per cent below 1990 levels is published in the 2020 net position report and in New Zealand’s second biennial report under the UNFCCC.

In previous years, New Zealand reported a ‘net position’ to track progress towards our 2008 - 2012 emissions reduction target taken under the Kyoto Protocol. New Zealand submitted a true-up report to the UNFCCC detailing how the 2008-2012 target has been met.  This true-up report was reviewed by an international team of experts in February 2016. The review report confirmed that New Zealand fully complied with its commitments for the first commitment period of the Kyoto Protocol.