New Zealand has set a target under the Paris Agreement for 2035 net emissions to be 51 to 55% below 2005 gross levels in 2005. This target can and should be strengthened: it is significantly below what the government’s independent expert Climate Change Commission found is possible and affordable. A stronger target supports transition to the 21st century low-emissions economy that will be a competitive advantage, and supports success of the global response that will reduce the damaging consequences of climate change.

This article unpacks the published 2035 NDC against criteria of the Paris Agreement, and finds that it:

1. Is not "highest possible ambition": The government’s independent expert Climate Change Commission advice showed that significantly stronger targets are feasible and affordable.

2. Does not reflect equity considerations: Ministry for the Environment analysis showed that a target of over 80% reduction would be required for strong alignment with equity principles.

3. Does not reflect “progression”: The level of effort to meet NDC2 is significantly less than for NDC1. 

In addition, the methodology change from a budget to a point-year target allows for extra emissions that were not adjusted for.

4. Is not consistent with Article 6 guidance: Use of Article 6 in NDC1 allows cumulative emissions to be higher than if the NDCs had been met domestically.

5. Has slower emissions reduction than the global average in 1.5C scenarios: The government’s claim that a 51% reduction is “above average” relies on inconsistent scaling.

Background 

New Zealand’s 2035 Paris Agreement target (its second Nationally Determined Contribution, NDC2) is to reduce net emissions to 51-55% below 2005 gross levels in the single year 2035. This follows its first Paris Agreement target (NDC1) which is for net emissions to reach 50% below 2005 gross levels in 2030. NDC1 is managed as an emissions budget across the years 2021-30 so all emissions in the period count, whereas NDC2 is only for the year 2035.

The minimal increase from 50% to 51% headline target was slated as “shockingly unambitious” when NDC2 was announced, particularly given Parties to the Paris Agreement’s recognition at COP28 that 

“limiting global warming to 1.5 °C with no or limited overshoot requires deep, rapid and sustained reductions in global greenhouse gas emissions of 43 per cent by 2030 and 60 per cent by 2035 relative to the 2019 level and reaching net zero carbon dioxide emissions by 2050”.

The New Zealand government however maintains that the NDC is a fair and ambitious contribution, and claims that it is an above-average reduction given New Zealand’s unique emissions mix. This note unpacks five reasons why those claims don’t stack up.

1. It is not "highest possible ambition" 

The government’s independent expert Climate Change Commission advice showed that significantly stronger targets are feasible and affordable.

Article 4.3 of the Paris Agreement requires Parties’ NDCs to reflect their “highest possible ambition”. Advice from New Zealand’s official Climate Change Commission showed scenarios with up to 66% reduction in the year 2035 are feasible and affordable domestically (green line in Figure 1), much deeper than the 51-55% range chosen. The Commission was only tasked with assessing domestic feasibility, not a global fair share or whether international cooperation should play a supplemental role, so their advice could be viewed as a floor not a ceiling for ambition.

Figure 1: New Zealand’s first and second NDC targets

2. The target does not reflect equity considerations

Ministry for the Environment analysis showed that a target of over 80% reduction would be required for strong alignment with equity principles.

Parties have agreed to implement the Paris Agreement on the basis of equity (Article 2.2). The Ministry for the Environment conducted an analysis of equity criteria, which found that a reduction of >80% in 2035 would be needed to strongly align with equity (purple on Figure 1). 

The Minister dismissed this as unrealistic domestically, but equity considerations could still have had influence: government officials noted that a target of 65% reduction would be ‘more’ aligned than a weaker one. International cooperation could also have played a role to increase feasibility. However given the eventual decision to adopt a 51-55% target, equity seems to have been ignored. 

Throughout the NDC2 decisions papers there is reference to New Zealand’s “national circumstances” (mostly in respect of having a high share of agricultural methane), but no meaningful reflection on how to apply the Article 4.3 requirement for NDCs to reflect “common but differentiated responsibilities and respective capabilities”.  In the information for clarity, transparency and understanding accompanying New Zealand’s NDC communication equity is not addressed, with claims to “fairness” of the NDC hinging on comparison to global-average reductions (see point 5 below).

3. While 51% is greater than 50%, that does not necessarily reflect “progression”

The level of effort to meet NDC2 is significantly less than for NDC1. In addition, the methodology change from a budget to a point-year target allows for extra emissions that were not adjusted for.

Article 4.3 requires that each NDC is a “progression” on the previous. The New Zealand government has interpreted this in a numerical sense: a 51% reduction is more than a 50% reduction. 

However the International Court of Justice’s advisory opinion on states’ obligations in respect of climate change said progression in the Paris Agreement means “that a party’s NDCs must become more demanding over time”.  That is, the measure is of increased effort.  If emissions are on a downward track under business as usual, a greater reduction number doesn't necessarily mean any increase in effort at all.

Figure 2 shows the deviation required from BAU (WEM scenarios) for New Zealand's 2030 NDC (left) and 2035 NDC (right). The 2021-30 NDC requires significant action and is only achievable through a combination of domestic reductions and international cooperation. The 2035 NDC requires very little beyond existing policies until after 2030, when a small deviation is needed. What's more, around half of that post-2030 deviation is only needed because of a gap created by cancellation of policies since 2023: bridging that gap can hardly be counted as additional effort.

The New Zealand government did not attempt to assess progression of effort in NDC2 - but this quick comparison suggests  that NDC2 is backtracking, not progression.

Figure 2: Effort to achieve NDC1 and NDC2, illustrated by the required deviation from business as usual path (“With Existing Measures” scenario). Effort reduces, not increases, from NDC1 to NDC2.

A second lens can be taken on progression. Given that given New Zealand's 2030 target is to reduce net emissions to 50% below 2005 gross levels, the bare minimum next step for 2035 would logically be to hold emissions at that level and make a slight reduction. That's shown on the left of Figure 3.

However, the intended NDC path actually looks like the picture on the right of Figure 3 (for a 51% NDC2): the government’s  intention is for emissions to track from 2030 domestic emissions (blue) down to the target level in 2035. That means that allowed emissions go up  in 2031 from the 2030 target level, and be higher than that 2030 target level in every year during the implementation period until just squeaking in with a slight reduction compared to 2030 in the 2035 target year. That allows around 24Mt of extra emissions than if emissions were held at the 2030 target level.

There are Paris Agreement accounting principles that can be drawn on to show why this is a problem, particularly environmental integrity (which would argue that accounting choices should not be made that allow emissions to be higher) and consistency (which would argue that the emissions impact of methodology changes must be corrected for, to ensure like-for-like comparisons over time).

New Zealand is entitled to shift its accounting from budgets to a single-year target in moving from NDC1 to NDC2, but in doing so it can't ignore the emissions impact. To avoid extra emissions (vs holding at the 2030 target), the single-year 2035 target would need to be deeper: around a 60% or more reduction.

Figure 3: The methodology change from a budget in NDC1 to a single-year target in NDC2 allows emissions to be higher than if a budget approach had consistently been applied.

4. The approach used is not consistent with Article 6 guidance

Use of Article 6 in NDC1 allows cumulative emissions to be higher than if the NDCs had been met domestically.

Article 6 guidance includes a requirement that "Each participating Party shall ensure that the use of cooperative approaches does not lead to a net increase in emissions of participating Parties within and between NDC implementation periods or across participating Parties". That is, Parties should not cause more emissions than if their same targets had been met domestically, without international cooperation.

The graph on the left of Figure 4 is broadly the path domestic emissions would have to follow to meet the 2030 and 2035 targets without Article 6 (domestic emissions would not in reality follow exactly a straight line - there would be small ups and downs). The grey area is cumulative emissions across the two NDCs.

The graph on the right of Figure 4 reflects the NZ government's proposed approach to NDC2. Domestic emissions in 2030 are only allowed to be higher than the target level in 2030 (while meeting the 2030 NDC) if Article 6 is used to close the NDC1 gap. If the path to reach NDC2 then sets off from the 2030 domestic emissions level rather than the 2030 target level, cumulative emissions across the two NDCs are higher than if the targets had been met domestically. This does not follow the Article 6 guidance.

Again, New Zealand is free to move from an emissions budget approach to a single-year target, but needs to think through the emissions consequences and adjust the ambition of the NDC2 to avoid any increase in cumulative emissions.

Figure 4: As shown on the right, use of Article 6 in NDC1 only allows 2030 emissions to be higher than the target level, causing cumulative emissions to be higher across the two NDC periods.

5. The emissions reduction is less than the global average in 1.5C scenarios

The government’s claim that a 51% reduction is “above average” relies on inconsistent scaling.

How can the New Zealand government claim that a 51% reduction is above average global reduction for 1.5oC scenarios, when the global average in those scenarios is a 60% reduction vs 2019 in 2035?*

The left graph in Figure 5 shows in green what a New Zealand net emissions range would be if it followed the average global rate of reduction for C1 scenarios for the IPCC AR6 database (median and interquartile range). Compared with this range, NDC1 looks about average, while NDC2 is much less ambitious than the global average reduction.

However the New Zealand government does not consider this a fair comparison, given New Zealand’s high share of livestock methane emissions. They instead calculated a rescaled global-equivalent pathway, scaling a percentage reduction in New Zealand’s AFOLU, waste, and fossil methane emissions at the corresponding global sectoral decline rates, while scaling New Zealand’s other emissions by gas at the global rate for those gases. The output is shown in orange in the left graph in Figure 5. Compared to the orange range, NDC2 looks reasonably ambitious.

There are two major problems with this rescaled pathway.

• First, there's an error in the calculation (note that the upper and lower rescaled interquartile ranges cross in 2025), because New Zealand emissions were scaled to the rate of change of global median and interquartile pathways, not to the average of underlying reductions rates by scenario.

• Second and more significantly, the disaggregation method by gas and sector is inconsistent. The choice was made to disaggregate by gas and sector where that most advantages New Zealand, and only by gas for other sectors. To illustrate how much this matters, the graph on the right of Figure 5 shows in purple what the rescaled global range would look like if New Zealand emissions scaled by gas and sector for both CH4 and CO2...* which results in a similar outcome to the all-gases  global range shown in green. Compared to the purple range, NDC2 is clearly well short of global average reductions.

Figure 5: New Zealand’s NDC1 and NDC2 compared to global average reductions, and global reductions rescaled for New Zealand’s mix of gases and sectors

New Zealand's longstanding position is that its emissions are unusual for a developed country because of high livestock methane emissions. That's true. However they are also unusual because of high forestry CO2 removals - and this has a compensating effect. If you only consider the methane, you get a false impression that a weaker path is justified. 

This article does not calculate a full alternative scaling here, but the simple comparison of Figure 5 illustrates that there is a significant problem with only disaggregating methane. If New Zealand  uses an approach of doing separate scaling by gas, it needs to be done consistently (e.g. by gas only, or by gas and sector for all significant sectors).

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*1. "Equal rate of reduction" is not an equity approach and is not a suitable basis for deciding targets on its own. But it's a comparison many countries make, and is the main rationale New Zealand used to justify its NDC.
 *2. BAU forestry projections were assumed, in the absence of a clear method to scale LULUCF on a percentage-change basis compared to global pathways. Alternatives based on percentage improvement would likely give an even deeper required reduction.

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Christina Hood is head of climate change and energy policy consultancy Compass Climate. Her current focus is on supporting climate NGO capability, and providing independent expert input to policymaking.

With thanks to Rebecca Peer, University of Canterbury, for her assistance.