8 things you need to know about the PCE’s new report on agricultural greenhouse gases

Paul YoungEnvironment8 Comments

Today Parliamentary Commissioner for the Environment Jan Wright launched her latest report, Climate change and agriculture: Understanding the biological greenhouse gases. The report aims to provide a fresh starting point for this important debate, which has up until now either been ignored or veered into unproductive mud-slinging. It’s a fairly hefty tome, at 84 pages, but as always Commissioner Wright and her team have put a lot of effort into making it readable. Here are our eight takeaways.

 1. Farmers deserve credit

Let’s start with the good news: since 1990, farmers have managed to reduce the greenhouse gas emissions per unit of product by about 20% on average. Of course, New Zealand is producing more meat and milk, so total biological emissions (methane and nitrous oxide) have still risen by 15% in that time. But without those gains in productivity the increase would have been about 40%. So let’s thank the farmers for that.

However, being one of the most efficient at producing high emissions-intensity food products doesn’t let us off the hook.

2. There are no silver bullets on the horizon

The report scans the state of affairs in the quest for technological solutions to reduce emissions from agriculture, and concludes there are no silver bullets. The research is promising, and Dr Wright highlights in particular the value of a methane vaccine if one could be found (because of the ease of administering it, this could be rolled out quickly and globally across all kinds of farming systems). However, even this may only reduce methane emissions from sheep and cattle by around 20%. We can’t sit back and hope technology will fix everything.

3. We need to diversify

The climate challenge is not going away – it will only get more acute, and the scrutiny on greenhouse gas emissions will only increase from here. To feed 9 billion or so people by 2050 within environmental limits, there will need to be a shift to lower carbon, lower impact diets. Rather than only looking at ways to do what we are currently doing more efficiently, we should be thinking hard about and experimenting with more planet-friendly alternatives. As the report says, “There is a clear need for research not just on management practices, but also on alternative lower emission uses of land.”

It’s promising to see Landcorp beginning to lead on this. However, a lot more of our agricultural research budget needs to be invested in looking at diversification rather than putting all our eggs in the basket of meat and milk.

4. There are things we can do now

The report debunks the claim that there are no ready emissions reductions to be made from agriculture. As we’ve seen, the sector overall has made impressive reductions in emissions intensity due to productivity improvements. But today’s performance across farms varies widely, by 2-3 times the emissions per hectare (although only in part due to management practices – there are other factors like climate and farm type). Bringing more farms up to best practice will help reduce emissions further.

One barrier the report identifies is some poor advice being given to farmers:

“Farmers are besieged with advice from different sources, including some with vested interests. Advice to farmers on management practices and diversification options that would really help reduce biological emissions should be provided by independent experts”

Similar points about the need for independent farm advice are being made in the water quality space.

5. There are win-wins to be had

While talk about reducing stocking rates is still sacrilege in some circles, the report states “there is a growing body of research and practice showing that farm profit can sometimes be maintained, or even increased, with fewer animals.” Lake View Farm near Hamilton provides a compelling case study:

“…The number of cows was reduced from 530 to 350 over a five-year period. A range of improvements to farm management led to lower input costs. Each cow became more productive, the milk produced by the farm remained the same. The outcome was increased profitability, a small reduction in methane, a reduction in nitrous oxide of 20-30%, and a reduction of nitrate leaching of 50%.”

That last statistic touches on the major synergies between climate change and water quality policies. While not all measures to reduce water pollution will impact on nitrous oxide emissions (e.g. riparian planting), there are many that tick both boxes (e.g. the use of feed pads in winter).

6. More trees, please

As Climate Change Minister Paula Bennett has recently discovered, trees are great. Not only do they remove carbon from the atmosphere, they can deliver a whole host of other benefits such as improving biodiversity and reducing soil erosion. Under rational climate change policy, we would be putting a lot of marginal farm land into regenerating native shrub or plantation forestry.

The report has a very helpful explanation of the different characteristics of (permanent) native forests vs (crop) pine plantations, and does some number-crunching on the potential for new forests to offset agricultural emissions. It finds:

  • A million hectares of regenerating native forest could capture the equivalent of about 17% of NZ’s current annual biological emissions for 50 years or more;
  • A million hectares of pine plantations could capture the equivalent of about 81% of those emissions – BUT this is a shorter-term hit if the forests are harvested. The benefit might last around 20 years – the age the land reaches its long-term average carbon stock assuming it is continually replanted on harvest.

These numbers need a disclaimer: they depend on how we are weighting the different greenhouse gases…

7. Methane is different, but we can’t ignore it

Which brings us to the metrics debate. As we’ve discussed before, the conventional ‘Global Warming Potential’ metric probably puts too much weight on methane given its short-lived nature. As the report states, “all metrics are problematic in some way”, and Dr Wright has refrained from making any judgements or recommendations on this.

The report doesn’t discuss the ‘two baskets’ approach, which does away with the idea of one universal metric and instead separates the long-lived gases (e.g. CO2 and nitrous oxide) from the short-lived ones (e.g. methane). For long-lived gases, it’s the cumulative emissions over time that determines the temperature impact; for short-lived gases, it’s mostly the annual rate of emissions – although there is some persistent effect due to warming of the oceans. OECD Environment Director (and former NZ Environment Minister) Simon Upton gave this approach a plug in his recent speech in Nelson, and it certainly warrants consideration.

The debate on how to treat and compare the different greenhouse gases will carry on, but we’d certainly agree with Dr Wright’s conclusion: “Carbon dioxide is the main problem, but methane is doing damage and cannot be ignored.”

8. Change is inevitable and the time to act is now

If there’s one key message from the report, it’s probably this. Farming in New Zealand has undergone major changes in the past, and with climate change and other environmental pressures it’s very likely it will need to adapt in the future. On top of that, there is the potential for technological disruption from the likes of synthetic milk and meat. It’s happened before with the advent of synthetic fibre (nylon) crashing the price of wool in the 1960s, and it could well happen again.

So it’s time for policymakers to get moving. In particular, we need to get the economic signals for future land-use change right, by pricing in externalities rather than continuing to ignore them. In Dr Wright’s words, “Making a smooth transition to producing lower emission food is very important. Continuing delay just makes an abrupt transition more likely.” To back that up we need to be investing some of our science budget in thinking what else we could do with our land if synthetic milk and meat catch on. Otherwise we face the risk of painful transition after being caught with all our eggs in one basket as we did in the 1960s.

8 things you need to know about the PCE’s new report on agricultural greenhouse gases was last modified: October 20th, 2016 by Paul Young
About the Author

Paul Young

Paul Young joined the Morgan Foundation in 2015. Paul has an academic background in physics and maths, and graduated with a Master's degree from University of Otago where he researched ocean wave power. He is one of the founders of Generation Zero - a Kiwi youth organisation that advocates for action on climate change. He is passionate about the role New Zealand can play in leading the way to a thriving zero carbon future. Paul conducts research for the Morgan Foundation on climate change and other issues, and writes the occasional blog post.

8 Comments on “8 things you need to know about the PCE’s new report on agricultural greenhouse gases”

  1. The sooner we start, the easier the transition will be. I suspect the public are ahead of the farming sector and the Govt on this.

  2. wow with 9 billion people… things will be…

    Actually perhaps we just don’t need 9 billion people- perhaps the people are the problem? chart the charts against human population increase. Oh look extremely strong correlation, probably even causation. If the humans can’t reduce , then the results are merely consequences…. or when do you think they’ll actually start dealing with the root cause? 5 billion? 9 billion? 90 billion? 900billion? When are you going to call “enough”

    1. If you break it down, things aren’t so bad. If you look at super developed places like Japan, the population there is actually falling, so we aren’t going to keep growing forever. And like it states in this article, we really just need to adopt a lower carbon diet to give the world some breathing space!

  3. I can’t help thinking that in agriculture there are two different kinds of CO2 emissions, the emissions that come from burning carbon dug out if the ground (coal and oil) and the kind that comes from animals eating vegetation, and converting this back to carbon dioxide by breathing, farting, burping etc, (including us). The first kind will raise the amount of CO2 in the atmosphere for ever – there isn’t a system to rebury it. The second kind is in an eternal cycle, the same carbon is absorbed from the atmosphere by plants, which either rot or are eaten by animals, even if they eat each other, and gets breathed back into the atmosphere. Planting corn, and feeding it to cows speeds up this process, but CO2 is both absorbed from the atmosphere faster by the more productive crop, and put back faster by the more productive animal systems. Slowing this down will make us feel better (we are reducing CO2 emmissions) but will it actually do anything if this also reduces the rate of absorbtion (by replacing corn with trees which absorb less per hectare)? What we really need is some way to stop digging carbon out of the ground and burning it, or getting it back underground in some way. Surely these biological emissions are a side show. We really need to wean our agriculture sector off oil. To my mind catching the methane and using it to run tractors would be much more useful than a methane vaccine that stopped cows producing the stuff.

  4. What is the position of non-animal agriculture – horticulture, grains, fruit etc. How do they compare in emissions and what is the prospect of agriculture moving in that direction?

    1. That’s a really good question, which deserves an answer. May I suggest that the lack of an answer so far is due to the tangled and confused way we handle agricultural emissions (see my previous post). For example, if we include the burps, farts and breathing of ruminant animals, carbon obtained from their feed, with the emissions from burning fossil carbon dug out of the ground to run tractors and make fertilisers in the pastoral farming total, but exclude the burps, farts and breathing of human animals, and compost heaps, that are emitted by the consumers of horticultural products, you get a very distorted view. (For those who don’t know much about ruminant digestion, the first stomach of a cow is basically a small, portable, compost heap, being kept nice and warm so it works faster, and allowing the cow to digest grass and get its nutrition from it). If you look at just the amount of fossil carbon burnt to produce the food in both cases, the picture is very different. So, if anyone has the figures to compare these, please include the basis for the calculation – it’s the only way you can get any credibility.

  5. Re ‘No Silver bullets on the horizon’, have writers of the report not taken into account current Australian research on a variety of seaweed growing off Queensland found to reduce methane emissions in livestock by 99% when small amounts are added to livestock feed? At first they thought their equipment must be faulty but not so. This would reduce our national emissions massively, if warming waters in Northland allow cultivation / harvesting of this variety.

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