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Farming: Future proofing the farm – greenhouse gas emissions

26 Oct 2018

Blake Holgate, a sustainability analyst with Rabobank based in Dunedin, gave us an overview of the issues farmers are dealing with on the environmental front. They fell into two categories:

  1. Greenhouse gas emissions
  2. Contaminant loss

I’ll look at his comments on greenhouse gas emissions in this letter and cover contaminant loss next time.

Blake referred to the New Zealand Productivity Commission report Low-Emissions Economy – Opportunities and Challenges for New Zealand, which came out in August this year.

They identify three shifts that must happen for New Zealand to shift to a low-emissions economy:

  1. We stop burning fossil fuels and switch to using electricity and other low-emission energy sources. This means a rapid switch of the New Zealand light vehicle fleet to electric vehicles and other very low-emissions vehicles (bikes), and a switch away from fossil fuels in providing heat for industry;
  2. We undertake substantial levels of afforestation to offset New Zealand’s remaining emissions. This will require massive rates of planting over the next 30 years, potentially approaching the highest annual rate ever recorded in New Zealand. (The prediction is that this will come from existing marginally profitable sheep and beef land); and
  3. We make changes to the structure and methods of agricultural production. This will include diversification of land use towards more horticulture and cropping, and greater adoption of low-emissions practices on farms.

Greenhouse gasses – can’t live with them; can’t live without them. They keep the planet warm enough to live on. Without them the earth’s average temperature would be about 0 degree Centigrade rather than the current 14 degrees Centigrade. Too much greenhouse gas and parts of the world become uninhabitable from over-heating. It’s the Goldilocks solution; not too hot, not too cold. At this point in the history of the planet we are fast leaving the Goldilocks solution behind.

We are, on average, 1 degree C hotter than pre-Industrial Revolution levels. It doesn’t seem much, but it is getting too hot on planet earth.

Our greenhouse gas emissions are amongst the highest per person in the world, despite having an electricity system that is overwhelmingly powered by renewable sources. This is primarily due to the high concentration of agriculture in New Zealand.

Yet the growth in greenhouse gas emissions in New Zealand since 1990 has come not from agriculture, but primarily from the increased use of fossil fuels, particularly from trucks and industrial heating. Let’s keep that in mind as we look at the cost of change and where it sits in the New Zealand economy.

Interestingly, while per person emissions are high, we produce less than 0.2% of global emissions, about the same contribution that our share market makes to the total world share market value.

Agriculture will have to play its part in reducing greenhouse gas emissions in New Zealand as it contributes nearly half of all greenhouse gas emissions we produce. We have the highest percentage of emissions coming from agriculture of any country in the OECD –

Graph 1: Agricultural emissions as a percentage of total country emissions - OECD countries

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Source:  OECD (2018a)

The main culprits within agriculture are the emission of (remember your 4th form science classes) methane (CH4), which is emitted by animals and is a short-lived problem (less than 20 years) and nitrous oxide (N20), which is emitted by fertilized crops. One of these gasses has a sweet odor, is known as ‘laughing gas’ and is emitted by the ocean as well. Do you know which one?

Graph 2: Where does the agricultural contribution come from?

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How adaptive are farmers going to be in moving to lower emissions? Good farmers are already taking these environmental challenges into account. Blake Holgate believes that environmental management of all kinds will become a core function of good farming practice in the future, if it isn’t already.

Changing land use

One of the answers to reducing greenhouse gas emissions from agriculture is to change the mix of land use. The Productivity Commission estimates that the required rate of land use change is comparable to the rate at which beef and sheep farms have converted to forestry and dairying over the past 30 years. That seems to put it into perspective and with the right incentives should be achievable.

Graph 3: Transition from livestock towards forestry and horticulture in New Zealand

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Source: Concept Consulting et al (2018a)

Greenhouse gas emissions are a hard problem to solve. The Governor of the Bank of England, Mark Carney (2015), puts the problem this way -

“Climate change … imposes a cost on future generations that the current generation has no direct incentive to fix”.

If you are interested, you can read the full Low Emissions Economy report here

Keep asking great questions …

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