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

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.