The government will shrink its 2050 methane emissions targets to a lower range of reduction than what’s currently legislated, and it will not pursue a tax on agricultural methane emissions.
New Zealand’s current domestic target is a 24 – 47% reduction in biogenic methane below 2017 levels by 2050. Today’s announcement now sets that range to 14 – 24%.
The Government says it’s changing this aspect of its climate change targets because achieving the upper end of the current range (47%) was “unrealistic”, and would create “economic uncertainty, risks exacerbating land use change, and could increase food production costs.” Targets set for 2030 will not change.
The Science Media Centre asked experts to comment.
Dr Jocelyn Turnbull, Principal Scientist, Earth Sciences New Zealand, comments:
“New Zealand is unusual across developed countries in that around half of our greenhouse gas emissions come from agriculture. Most of those agricultural emissions are methane, a potent but relatively short-lived greenhouse gas. New Zealand’s Zero Carbon Act already has a split target – with a net zero 2050 aim for long-lived greenhouse gases (mostly carbon dioxide with a few others as well), and a 24-47% target for biogenic methane. The key difference is that to stabilise long-lived CO2 in the atmosphere, emissions must go to zero. Whereas for short-lived methane, emissions have to stabilise to keep methane from increasing in the atmosphere, or ideally methane emissions will reduce to gradually bring down methane levels in the atmosphere.
“Today’s government announcement to reduce the biogenic methane goal puts New Zealand in the ‘stabilise methane in the atmosphere’ camp, rather than the more ambitious ‘reduce methane in the atmosphere’ camp. On the international stage this move could impact on our ‘clean and green’ image that helps us command a premium on our products.
“It is good to see the continued investment in agricultural methane ‘vaccines’ and other mitigation methods.
“But methane is not the only greenhouse gas from agriculture, carbon dioxide is produced by farm equipment, transportation of goods to and from, and a big source from milk factories. These are all things that we already know how to mitigate – with renewable energy and electric vehicles. This is an opportunity for farmers and agricultural companies to make a difference right now.”
No conflicts of interest.
Professor James Renwick, Victoria University of Wellington, comments:
“The Government’s announcement on methane emissions reductions represents a major step backwards in ambition and in climate action. The methane reductions mandated under the Zero Carbon act called for 24-47% reductions by 2050, in line with the science of the IPCC report on 1.5°C of warming. The revised emissions reductions are 14-24% by 2050, so the top of the new range is below the bottom of the old range.
“The idea of ‘no additional warming’ seems to have won the day, in terms of scientific advice to Government. This approach goes easy on the agriculture sector and in no way does it represent our ‘highest possible ambition’ as laid out in Article 4 of the Paris Agreement, to which New Zealand is a signatory. Our trading partners are unlikely to smile on this reduction in ambition.
“The climate is currently changing rapidly and we need to be doing all we can to slow the warming and avoid catastrophic impacts from extremes and from tipping points crossed. Yes, carbon dioxide emission reductions are the number one target, and we must get to zero as soon as possible. But methane emissions are the next most important, and emissions reductions there would quickly translate into reductions in atmospheric concentrations (because of the short lifetime of methane in the atmosphere), providing a cooling effect in the short-medium term. To pull our weight internationally under the Paris Agreement, New Zealand should still be aiming for the reductions set as law in the Zero Carbon Act, not these watered-down targets.
“This week, a major international conference on climate change adaptation is taking place in Christchurch. We can currently adapt to climate change pressures, in most places, most of the time. Every tenth of a degree of warming makes that adaptation harder, and at some point we will no longer be able to adapt. There is real urgency around reducing emissions of all greenhouse gases, in every sector and every country. This can be achieved by working as hard as we can across the board. The new methane targets increase the risk of unmanageable consequences from climate change.”
Conflict of interest statement: “I receive funding from MBIE through their Endeavour Fund. I was a Climate Change Commissioner 2019-2024 but no longer have any affiliation there. I was a Lead Author with the IPCC 2001-2021 but am not involved with the 7th Assessment Report.”
Laura Revell, Associate Professor of Atmospheric Chemistry, University of Canterbury, comments:
“Biogenic methane emissions in New Zealand increased substantially during the 20th century and have largely stabilised so far this century.
“As part of the independent methane science review, we modelled methane cuts needed to ensure no additional warming relative to 2017 levels. Our results show that the level of cuts needed depends on global methane emissions.
“How methane heats the atmosphere is a bit like pouring water on a sponge. If the sponge is dry, even a small amount of water makes it damp. If the sponge is already saturated, adding more water has little effect.
“Similarly, methane’s warming impact decreases at higher concentrations (and is influenced by nitrous oxide, another greenhouse gas) because the relevant infrared absorption bands become saturated.
“Because atmospheric methane concentrations are continuing to increase – driven largely by emissions from other countries – steeper cuts to New Zealand’s emissions alone would have little impact on total atmospheric heating.”
“If the rest of the world makes steep cuts to methane emissions, then New Zealand would need to make steeper cuts too to ensure the no additional warming target is met. Periodic reviews of the target seem sensible.”
Conflict of interest statement: “Laura Revell served on the independent Methane Science and Target Review panel. She is a lead author on the forthcoming Intergovernmental Panel on Climate Change assessment (AR7).”
Dr Christina Hood, Independent climate change and energy policy expert at Compass Climate, comments:
“New Zealand’s recent Paris Agreement target update was shockingly unambitious, but today’s decision goes even further: we are now backtracking. I am not aware of any government that has weakened an existing legislated domestic climate target – this may be a dubious first for New Zealand.
“Because methane is such a potent greenhouse gas, the extra warming caused by weakening the target is massive: it is roughly equivalent to tripling all of our other emissions out to 2050. New Zealand’s current emissions cause around $20 billion of global climate damages each year – we should be doing whatever we can to reduce that.
“The independent Climate Change Commission has found that rapid emissions reductions – in methane and in other gases – are feasible and affordable, and set New Zealand up to be competitive in a future low-carbon world. We should be aligning our economy for the 21st century, not the 19th.”
No conflicts of interest.
Dave Frame, Professor of Physics, University of Canterbury, comments:
“The Government signalled a while ago they would alter the methane targets. This seems reasonable under the circumstances. The circumstances are that the Ardern Government made a somewhat heroic set of assumptions in the Zero Carbon Act (2019) about the world’s progress towards the lower end of the Paris Agreement’s temperature goal; heroic assumptions that seem to have constrained the Climate Change Commission’s thinking and which have, unfortunately, been shown to be a very long way from reality.
“The sad and unavoidable fact is that the world will soon go zooming past 1.5C. Global agricultural methane emissions have risen by 4.1% since 2015, while to stay under 1.5% they ought to have dropped by at least several percent by now. Consequently, there is a question that New Zealanders need to think about: ‘what is it reasonable for us to do, given the observed lack of action elsewhere?’ The revision is this government’s answer to that question.
“Other countries that made ambitious commitments in the first few years after Paris will also face pressure as the gap between domestic policy, international policy, and stated ambition grows further. My guess is they will come to similar conclusions and scale their commitments more closely to what’s going on in other countries. This is probably electorally prudent, and superior to the alternative. If the more ambitious players find their commitments proving unsustainable, and see inaction elsewhere, they will experience political reaction. The practical alternative to scaling back or matching commitments may be ditching them entirely, and this would be much worse.
“I’m disappointed the government seem to be ruling out a price on methane emissions. Centre-right governments understand in their bones that if you want less of something, one of the very best tools is to make it more expensive. This decision will almost certainly be revisited by a future Labour government who will want to create a price to drive further emissions reductions. The current government’s failure to do this actually undermines their attempt to ensure two-basket policy. A price on methane emissions outside the ETS would likely be increased by Labour; its absence is regrettably another opportunity to go back to the discredited idea of putting agricultural methane in the ETS.”
Conflict of interest statement: “I was on the Methane Review Ministerial Advisory Panel tasked with finding a range consistent with No Additional Warming.”
Ralph E H Sims, Professor Emeritus, Sustainable Energy and Climate Mitigation, Massey University, comments:
“A molecule of methane in the atmosphere adds to global warming for the few years it is present – then continues to warm for years after it is converted to CO2.
“The IPCC argues that methane emissions produce around 30% of total warming and need to be reduced urgently as well as CO2 in order to keep warming below the Paris target of 1.5 degrees.
“There is no guarantee that scientific research will provide solutions to biogenic methane in the near future as hoped for by NZ government.
“The farming industry is likely to be highly impacted by future extreme weather events as a result of climate change. One would think they would support every initiative possible to reduce emissions urgently.”
No conflicts of interest.
Distinguished Professor Robert McLachlan, School of Mathematical and Computational Sciences, Massey University, comments:
“The decision to weaken emissions targets and to defer important decisions on emissions budgets by two years is a significant assault on the environment, on the integrity of the Climate Change Response Act and on New Zealand’s contribution to global climate goals. It makes a mockery of the Act’s purpose to ‘contribute to the global effort under the Paris Agreement to limit the global average temperature increase to 1.5° Celsius above pre-industrial levels’.
“The EU-NZ Free Trade Agreement includes the obligation to ‘refrain from any action or omission that materially defeats the object and purpose of the Paris Agreement’ and includes the provision that Parties may take ‘appropriate measures’ in the event of such acts or omissions. I’d like to see the Government’s legal advice on this and which measures from the EU they anticipate. This was a flagship environmental FTA provision led by the EU.
“The Act is already under threat as the Government and the independent Climate Change Commission have reached very different conclusions on its interpretation and, increasingly, on the impact of government policies. For example, the second carbon budget (2026-2030) is 305 Mt CO2e while the Government’s forecast is 301 Mt. The Commission’s forecast is 314 Mt and they have advised that, in accordance with the Act, the budget should be reduced to 290 Mt. The Commission also found that virtually all of the government’s planned climate actions were at risk of non-delivery. The disparity is even more extreme for 2031-2035. Yet today a two-year delay in responding to this advice has been announced.”
No conflict of interest.
Dr Nathanael Melia, Director, Climate Prescience Ltd; and Senior Research Fellow, Victoria University of Wellington, comments:
“The Government got the science right but hedged on ambition—24 percent by 2050 is the number consistent with Paris 1.5 °C, and that’s where New Zealand should land.
“The rubber is hitting the road—and this Government has chosen to keep its route options open. Let me start by reminding everyone that every unit of carbon dioxide (CO₂) emitted causes additional warming, while every molecule of methane emitted sustains previous warming. The science of how greenhouse gases warm the planet isn’t the most complex part of climate science; the brain power in this field is asking the right questions and interpreting the answers correctly. On that front, the Government has got the science bit right.
“The Government has been indecisive is in the policy translation of that science. The upper end of the range 24 percent methane cuts by 2050 is the number consistent with the Paris Agreement’s goal of keeping global temperature rise well below 2 °C and pursuing 1.5 °C. That’s the number they should have gone all-in on. By leaving the target as a range, they’ve invited both criticism and potential legal challenge over whether the lower bound meets New Zealand’s international obligations.
“I’ve long championed treating methane differently from carbon dioxide in domestic policy, an approach developed through work with Professor Dave Frame and the Parliamentary Commissioner for the Environment. This scientific separation now underpins New Zealand’s climate architecture.
“To me, the next steps are clear:
- “Apply appropriate pressure to ensure methane cuts reach above 20 percent, and settle the target’s adequacy through the courts if necessary.
- End the distraction of debating methane targets and redirect full attention toward cutting CO₂, which locks in warming for millennia with every molecule emitted.
“Lowering New Zealand’s methane emissions as laid out in this plan will directly reduce global temperatures. I don’t mean stop warming. I don’t mean reduce New Zealand’s contribution to the temperature increase. It will literally cool the planet.”
Conflict of interest statement: “No financial interests in methane-mitigation technologies or agri-sector programmes. My first job when I was 16 was on a dairy farm. I have been mentored by and studied under those IPCC scientists who invited much of this climate science. I am friends with scientists on the government’s Methane Science and Target Review Panel. My boys and I consume A LOT of milk and have nice strong bones.”
Dr Luke Harrington, Senior Lecturer in Climate Change, University of Waikato, comments:
“For the warming associated with long-lived greenhouse gases to stabilise at any level (i.e. ‘no added warming’), annual emissions from those long-lived greenhouse gases need to reduce to net zero. This is true for both carbon dioxide and nitrous oxide emissions (most of the latter being linked to agriculture in New Zealand). Annual emissions of short-lived greenhouse gases, like methane*, do not need to reduce to zero for the warming associated with those emissions to stabilise – rather, for the case of New Zealand, biogenic methane emissions only need to reduce by between 10 and 25% for that to occur (depending on assumptions about the reference year and what happens to global methane emissions in the future).
“If biogenic methane emissions were to reduce by much more than 25% by 2050, this would effectively ‘reverse’ some of New Zealand’s past methane-induced contributions to global warming. In the same way, if we were to pull more carbon dioxide out of the atmosphere than we emitted at some point in the future (i.e. net negative emissions), this would also have the effect of “reversing” past CO2-induced warming contributions.
“That’s largely where the science stops. Determining whether our 2050 targets should be based on a policy of maximum ambition or consistency with temperature stabilisation is a value judgement. Likewise, whether historical warming linked to agriculture in New Zealand is larger than our ‘fair share’ is another value judgement. Both can be informed by a range of equity considerations but there is no one ‘correct’ answer. My personal view is that the biogenic methane target should narrow to a 25-35% reduction by 2050.
“There are three other points to note.
“First, the original 24-47% 2050 target for biogenic methane was found by making inferences from integrated assessment model scenarios used in the IPCC’s 2018 Special Report on 1.5°C. This scenario ensemble was never designed to be used to set targets at the national scale – rather, they were highly aggregated global storylines, intended to explore a multitude of different pathways to a low-emissions future.
“Second, it’s worth noting that if the warming associated with agriculture in NZ were to be considered as a whole, then hard-to-abate nitrous oxide emissions should be taken into account, too.
“Third, if we are willing to adjust methane emission reduction targets to be consistent with prescribed temperature outcomes, the same argument should also result in the target year for when we reach net-zero CO2 emissions being brought forward.
“*Not all methane sources are comparable. Unlike biogenic methane, fossil methane (i.e. natural gas) introduces a new carbon atom into the atmosphere after it breaks down into carbon dioxide – this is why it should be viewed as equivalent to a long-lived greenhouse gas and why it also needs to reduce to net-zero by 2050 in the Zero Carbon Act.”
Conflict of interest statement: “I lead projects funded by MBIE (Smart Idea), the Royal Society (Marsden Fund) and the Natural Hazards Commission (University Research Programme). I also have funding for climate extremes work linked to the Resilient Pastures project – this is funded by both industry and MPI via their Primary Sector Growth Fund”.