Historical emissions data were obtained from latest government data, the New Zealand’s Greenhouse Gas Inventory 1990-2018 published in April 2020 (Ministry for the Environment, 2020b).
NDC and other targets
Target emissions levels were calculated from New Zealand’s Greenhouse Gas Inventory 1990-2018 published in April 2020 (Ministry for the Environment, 2020b).
The target for 2020 (5% below 1990) is based in the gross emissions in 1990 (i.e. LULUCF emissions are not included in the base year). The comparison calculations using the CP1 surplus and Kyoto Protocol forestry activities data is from the latest net position report (Ministry for the Environment, 2020a).
The target for 2030 (Paris Agreement Nationally Determined Contribution or NDC) is a 30% emissions reduction below 2005 levels. It is equivalent to a reduction of 11% from 1990 levels (New Zealand Government, 2016a). The same target is reiterated in New Zealand’s updated NDC (New Zealand Government, 2020). We have assumed full LULUCF accounting in the target year as New Zealand uses a gross-net approach. For the 2030 pledge, we have estimated levels of emissions excl. LULUCF resulting from the NDC by subtracting Kyoto Protocol forestry activity emissions in 2030 from the targeted level (2030 data from: (Ministry for the Environment, 2019a)). We compare the Kyoto Protocol forestry emissions with the government LULUCF projections range (Ministry for the Environment, 2019a). The Kyoto Protocol forestry emissions fall within the LULUCF range.
The 2050 Long-Term Target has been quantified using the latest government historical data (Ministry for the Environment, 2020b). The CAT estimates the target by subtracting LULUCF and including methane emissions.
The projected LULUCF emissions for 2050 are based on the latest government projections prepared for the Fourth Biennial Report (Ministry for the Environment, 2019a). The government LULUCF projections provide a range based on “lower removals” and “upper removals”. CH4 emissions for 2017 were also available in the government data prepared for the Fourth Biennial Report (Ministry for the Environment, 2019a). We include emissions from methane and exclude LULUCF to reach the target of 67 MtCO2e. We assume COVID-19 had no impact on government projections for the LULUCF sector.
Current policy projections
The current policy projections are based on the “with existing measures” scenario of the 4th Biennial Report of New Zealand. The full data file for this scenario was sourced from: (Ministry for the Environment, 2019a). The scenario details can be found in the Fourth Biennial Report (Ministry for the Environment, 2019b).
The government projections from the Fourth Biennial Report include the effects of key quantifiable policies and measures implemented prior to 2019. Specifically, it includes the New Zealand Emissions Trading Scheme; Efficient Products Programme, Insulation and heating grants programmes; Productive and Low Emissions Business Programme; Kigali Amendment to the Montreal Protocol; National Policy Statement for Freshwater Management; Indirect effects of combined forestry land-use policies on agricultural land use; Afforestation Grant Scheme; Permanent Forest Sink Initiative; Sustainable Land Management Hill Country Erosion Programme; Erosion Control Funding Programme; One Billion Trees Programme; Crown Forestry Joint Ventures; National Environmental Standard for Air Quality (landfill methane); Waste Disposal Levy; Indirect effects of combined agricultural (forestry and landuse) policies on waste; and the Tokelau Renewable Energy Project. (The current policy projections do not include the NZ ETS reforms of June 2020.)
Planned policy projections
New Zealand’s Fourth Biennial Report has a 'with additional measures' (WAM) scenario (Ministry for the Environment, 2019b). This scenario includes all policies in the “with existing measures” scenario described above plus pricing on agricultural emissions with 95% free allocation planned for 2025. The CAT applies interpolations for years not reported. The WAM scenario is harmonised to historical data.
We applied a novel method to estimate the COVID-19 related dip in greenhouse gas emissions based on GDP projection data from national and international sources. The CAT distilled the emission intensity (GHG emissions/GDP) from a pre-pandemic scenario based on the Fourth Biennial Report and applied the GDP projections to take into account the effect of the pandemic. The uncertainty surrounding the severity and length of the pandemic creates a new level of uncertainty for current and future greenhouse gas emissions. To capture a wide range, we used both international and government scenarios to develop a minimum and maximum range.
The CAT compared GDP projections from OECD, IMF and five scenarios from the New Zealand Treasury (IMF, 2020; New Zealand Treasury., 2020; OECD, 2020). The CAT uses the scenarios that show the largest range of emissions for 2030 to account for the uncertainty of the impact of COVID-19, in relation to assessing the NDC target. The scenarios that produced the largest range were the OECD double hit scenario and the Treasury Scenario 2. The OECD double hit scenario accounts for the possibility of a second wave of COVID-19 transmission in New Zealand, with GDP decreasing 10% in 2020 and increasing 3.6% in 2021. The Treasury Scenario 2 considers the impact of COVID-19 at an official ‘alert level’ 4 for three months and ‘alert level’ 1 or 2 for nine months. Scenario 2 GDP projections indicate a -19.5% drop in 2020, followed by 21.5% rebound growth in 2021, 7% in 2022, and 4% in 2023. (Note that the Treasury provides data for years up to March. We have not corrected the data but applied, for example, year “2021 to March” to our calendar year data of 2020). The Treasury scenario includes the current level of fiscal response of NZ$20 billion, and explains the economic rebound.
The COVID-19 scenarios from OECD and the Treasury are used to estimate emissions from 2020 to 2021 (OECD) and 2023 (Treasury). The emissions intensity for 2020 to 2021/3 are derived from the COVID-19 scenarios. The CAT applies the growth rates of the pre-pandemic emissions intensity from 2021/2 to 2030. The CAT calculates the emissions from the emissions intensity inclusive of COVID-19 impacts to 2030, and then applies the growth rates from the pre-pandemic current policy emissions scenario to extend the emissions data to 2050.
For the planned policy projections, CAT calculated COVID-19 emissions into the WAM scenario with the same method as described above.
Global Warming Potentials
The CAT uses Global Warming Potential (GWP) values from the IPCC’s Fourth Assessment Report (AR4) for all figures and time series. Assessments completed prior to December 2018 (COP24) used GWP values from the IPCC’s Second Assessment Report (SAR).