The NZ system for GHG reporting will be crucial

Big decisions still lie ahead as to how New Zealand reports its GHGs to the United Nations. Keeping short and long-life gases separate in the reporting headlines is vital.

A key forthcoming decision for New Zealand is how it will report to the United Nations on its Paris Agreement milestones.  On the surface, this many seem something for the bureaucracy to deal with, but the reality is very different. The issue is of fundamental importance.

The big question is whether New Zealand highlights the so-called total carbon dioxide equivalent number (CO2e) or whether it highlights the separate targets and achievements for short and long-lived gases. Once determined, the reporting metrics are locked in.

This question has been raised by the Climate Change Commission (CCC) in its draft report. Unfortunately, the issue has subsequently been largely ignored by the media, by commentators and also by rural industry groups, all of which have failed to recognise its importance in shaping the issues.

The CCC lists many recommendations in multiple categories and asks 24 consultation questions. Recommendation One in the Nationally Determined Contributions (NDCs) category is that New Zealand should report internationally using a combined figure for short and long-lived gases. Question 22 is whether or not this is the best way to do it. I say that it is not.

To understand why this is so important, we need to backtrack about three years. At that time the dominant perspective within Government was that short and long-lived gases could all be bundled together. But then, Simon Upton in his role of Parliamentary Commissioner for the Environment presented arguments why they should be considered separately.

Neither the Greens nor the Labour Party were impressed with those arguments, but Winston Peters picked it up. Hence, separate targets have been listed in the Climate Change Response (Zero Carbon) Amendment Act 2019.

This Act says that New Zealand must reduce net emissions of all greenhouse gases except biogenic methane to zero by 2050. In contrast, biogenic methane has to be reduced by 24-47% below 2017 levels by 2050, including 10 per cent below 2017 levels by 2030.

Those emission reductions for methane are going to be challenging, but not impossible. The target is much more achievable if the 24% minimum figure is the one that is retained.

There are two very good reasons why agriculturally sourced (biogenic) methane needs to retain its strong separate focus. The first reason is very specific within Article 2 of the Paris Agreement.

Article 2 says that countries should “adapt to the adverse impacts of climate change and foster climate resilience and low greenhouse gas emissions development, in a manner that does not threaten food production”.

This statement is not hard to find. Article 1 of the Agreement is simply definitions. The statement about food production in Article 2 is in the first substantive paragraph of the Agreement.

So, let me say it very clearly: the Paris Agreement is not meant to threaten food production. Linked to this is something else I have said many times before: most of New Zealand’s pastoral soils and topography are not suited to crops.

Despite the prominence of the Paris Agreement statement about not threatening food production, it is almost never referred to either by mainstream New Zealand media, nor emphasised by rural industry groups.  Instead, the agricultural industries have allowed themselves to be side-tracked into fights that they can never win.

Too often we read about rural groups arguing that agriculturally-sourced methane is unimportant in relation to global warming. Yes, it is correct that the agriculturally-sourced methane in New Zealand is produced from carbon dioxide that is drawn from the atmosphere by photosynthesis, and this eventually ends up back in the atmosphere as carbon dioxide. However, in the meantime while it is in the form of methane for approximately 12 years on average, it does contribute to global warming.  Based on the science, we can never win an argument to the contrary.

People also get unduly distracted by issues of soil carbon. Yes, the carbon that is contained in the soil is very important, as is the carbon contained in the world’s rain forests. But greenhouse gas policies are measured by new sequestration and not by stores of carbon.  If agriculture wants to get credit for soil carbon, it will have to be new carbon that is sequestered net of any carbon that is being lost, for example by draining peat soils and by cultivation on all soils. Agricultural interests might win a few battles but they won’t win the war this way.

The second area that agriculture should be focusing on is the impact of bundling the methane into units of carbon-dioxide equivalence. This started almost by accident way back in the 1990s using the 100-year warming estimate of a tonne of carbon dioxide as the baseline. Most countries did not care greatly about the use of carbon dioxide equivalence for methane, given that for most countries biogenic methane is a minor component of total emissions. But for New Zealand and some other small agricultural exporting countries like Uruguay, it is a choice that totally screws the scrum.  If, for example, the effects of methane and carbon dioxide are compared based on 200-year effects then we would get a greatly reduced proportion of CO2e coming from methane.

The key issue with CO2e measures for methane is that it is like comparing apples and onions. There is no sensible way of bundling up the onions into apple equivalents. It could be on the basis of sugar, carbohydrate, fibre or even some unit of smell. Take your pick and get your answer!

Way back in 2006, I took up the issue of flaws in the CO2e concept when applied to methane. The article was published in the Journal of Primary Industry Management. Almost certainly, I was the first person to take up this issue in New Zealand. But no-one seemed particularly interested and at the time I had other fish to fry. I did not persist with the issue.

The key message in all of this is that the rural sector of New Zealand needs to fight to keep methane issues separate from carbon dioxide. Once they are bundled up into units of CO2e, there is no way that methane will receive the separate consideration that it needs. That includes the way that we report these issues to the United Nations, which will flow straight back into New Zealand reporting.

In contrast, the CCC report (p163) advocates bundling everything into one headline number. It suggests that there might be other ways of highlighting the special issues of methane but gives zero indication of how that might occur. I see that as a big cop-out. And it locks in that headline number as a mandatory requirement.

One of the problems for the rural sector has been insufficient expertise on greenhouse gas issues within industry bodies such as Federated Farmers. I have yet to find any professional staff in that organisation who can engage with the issues at the necessary level of depth. The industry has been fortunate that people like Parliamentary Commissioner Upton have rolled up their sleeves and generated useful debate from a position of insight. But that does not replace the needs for groups such as Federated Farmers to have their own professional specialists who can engage with these issues from a similarly informed position.


About Keith Woodford

Keith Woodford is an independent consultant, based in New Zealand, who works internationally on agri-food systems and rural development projects. He holds honorary positions as Professor of Agri-Food Systems at Lincoln University, New Zealand, and as Senior Research Fellow at the Contemporary China Research Centre at Victoria University, Wellington.
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16 Responses to The NZ system for GHG reporting will be crucial

  1. confoodnet says:

    Clear and cogent as always. Thanks Keith

  2. Tim Morris says:


    Where you say “most of New Zealand’s pastoral soils and topography are not suited to crops”, do you have somewhere we can read more. I come to a somewhat different conclusion. Clearly not all, but clearly not none. There is a big “size of the prize” here if we can up high intensity production. 1% of Canterbury is in horticulture. Canterbury is the size of the Netherlands. The Netherlands exports twenty times more food than Canterbury. Are you really sure Canterbury can’t produce more food?

    I’d argue there is a strong cultural bias here. If New Zealand had been colonised by China or Japan, a lot more would be cultivated. Look at the Kaipara. If that was colonised by China two hundred yers ago it would produce fifty times more food today than it does now.


    • Keith Woodford says:

      Focusing first on Canterbury, you are correct in saying the area is similar to the Netherlands. But only about one quarter of Canterbury is the plains, with the rest being the downs, the hills, the high-country, the lakes, the Mackenzie Country and the Southern Alps including Mt Cook (which lies east of the Divide and totally in Canterbury).
      The major soil types of the Canterbury Plains are the Lismores and Eyres which are stony, shallow and drought prone. In general these will not carry crops such as wheat, and even with irrigation this would be frowned on as depletive and non sustainable, and requiring big inputs of fertiliser – much more than required for dairying.
      The major Canterbury cropping soils lie along the south bank of the Rakaia with wind blown loess from the mountains and to a lesser extent on the south bank of the Waimakariri. There are also good cropping soils in parts of Ellesmere District together with small patches both north and south thereof such as Temuka where the soils tend to be deeper and less stony.
      Even on the cropping soils good husbandry requires animal phase interspersed with cropping. These soils have many constraints which large parts of Europe and America do not have.
      Given our distance from markets, the crops we do grow have to be high value and with long shelf life. Those market requirements tend to lead us towards particular animal products.
      Crops such as blackcurrants have been tried many times. We can grow the crops OK but making a profit is another matter. More people have lost money than made money out of blackcurrants.
      In Marlborough where the land is suitable for grapes then the flat and north-facing land is nearly all taken up by grape growing.
      The ideal crop growing regions tend to be places where there is reliable summer rainfall but not too much rainfall. It is very hard to make money growing crops in places like Taranaki. Some of the Waikato soils are suitable for cropping but many of the volcanic soils are not at all suitable.
      Kiwifruit growing continues to increase and varieties are being developed for particular regions – for example red kiwifruit in Northland. There is also increasing growing of sub tropical crops in Northland wherever the soils are suitable.
      I expect that new cropping opportunities will emerge, but it is real hard work not just to find the crops that will grow, but to link the products to markets. Also, leaching losses from crops such as potatoes can be very heavy.
      I would like to see us putting more effort into tree crops but I think that in the greater scheme of things these will be niche opportunities. Also, it is not as if people have not already been thinking about this for a long time.

      • Paul says:

        Not to mention the big elephant of International Ag Policies / subsidies that limit ability to grow such crops viably, even where feasible.

      • Keith Woodford says:

        In the greater scheme of things the effect of international subsidies on our ability to grow and market crops economically is a relatively minor consideration. There are other much bigger constraints.

  3. You are right on the money here Keith, excellent article.
    It is important to get NZ to understand the importance of food production and the difference between ST and LT gases.
    Keep up the good work and kia kaha sam

  4. trlahh says:

    Hi Keith,
    You might like to check out the submission prepared here (scathing of CCC math)

    BNNZ have also prepared a submission which we shall circulate after submission date.
    your comment: “If agriculture wants to get credit for soil carbon, it will have to be new carbon that is sequestered net of any carbon that is being lost,” …we have some thoughts on this!

    • Keith Woodford says:

      Hi Trlahh
      My overarching thought is that the submission of your society builds on the onions being converted into apples (i.e. the use of CO2e). In the NZ context, it is possible to have a legalistic discussion on that basis but it is not possible to have a logical science-led discussion on that basis.

  5. robin gardyne says:

    I am saddened that the lie that co2 is at the root cause of “climate change” has persisted so long. Co2 is essential for plant gowth and evidence of it’s benefit is shown in enhanced tree growth ,record harvests and reduction of desert areas. Why does co2 get the bad press when water vapour is much more abundant in the atmosphere ?CO2 produced by human civilization is said to be 3% , the rest is said to be naturally produced by vegetation,volcanoes  animals etc CO2 accounts for 4% of the atmosphere. To my calculation scientists are saying, that 3% 0f 4% has changed the climate in the last 120 years because of the actions of man. Further they would venture to include that by paying carbon taxes that magically the IPCC can make life better for everyone. Earth is 93miillion miles from the sun as we orbit around is ,surely any wobble or devience is more likely to change weather on earth the 0.001 rise in the co2 content of our atmosphere. Yours faithfully Robin Gardyne

    • Tim Morris says:

      Reading your comment I was confused as to whether this was your own theory (“The Robin Theory of Climate Change”) or you were quoting some science based source?

      I occasionally edit various Wikipedia pages on subjects I know something about. In “wikipedia-speak” can I say: Citation Required.

      • robin gardyne says:

        I read a Patrick Moore I agree with .There is no Climate Alarm. The earth is greening, desserts are smaller. Co2 is not poisoness. It is plant food

      • robin gardyne says:

        Some is my own experience as I farmed I southland for 45years+ I also read and Patrick Moore is one I think who has understood climate best. Airpressure changes climate not co2

  6. Paul says:

    Macaulay Jones is the person you need to speak to at Fed Farmers. And yes he understands this very well – 021 571 853

  7. David Porter says:

    I’m again coming late to this discussion but thanks Keith, well argued and keep up the good fight for science based decision making.
    It’s only a small part of your post but paying farmers for sequestering C into soils seems to be a fast growing market as a lazy way for some corporates to claim that they are C neutral.
    It’s a real minefield! Apart from the impossibility of measuring it in a precise way over time, what happens when, though one of the myriad ways of it occurring (a dry year, cultivation, change of crop etc.) your soil C reduces? Does the farmer pay back the corporate the money that they accepted to sequester the C. Also, what does the corporate then do?
    I listened to a Tim Hammerich Future of Ag podcast featuring Paige Stanley who had just finished her PhD at UC Berkley and she cast huge doubt about our ability to measure soil C sequestration. She spoke about how, with current understandings, it is impossible to predict how a certain farming practice will lead to a predictable amount of net C being sequestered.

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