environment

A curious anomaly in the Mackenzie Basin

The conversion of part of the South Island’s Mackenzie Basin to industrial scale dairying and beef farming is contentious for more than its location and scale. It raises issues that lie at the heart of the Government’s discussion paper Our Climate Your Say: consultation on the Zero Carbon Bill.

There’s a curious anomaly in the set up at Simons Pass station. When it begins operation this spring it will be one of the most modern farms in the country – energy efficient, hi-tech. The tractors will be driverless electric ones, the cows will come in to the robotic milkers whenever they feel like it. The fences will be virtual - GPS-controlled collars the animals wear will ensure they stay within allocated boundaries.

“It’s a large property if you have to drive someone 10km to the end of the farm,” owner Murray Valentine is reported as saying in Dairy News. “Better to send a drone down, have a look, then come back.”

But efficiency can do nothing about the methane issuing from 5000 dairy cows, up to 8000 beef cattle and more than 3000 sheep. Efficiency can manage but not avoid nitrous oxide. Yet these two are among the worst greenhouse gases on the planet. They are also the ones which will cause the worst headaches for the Government as it plots the details of the Zero Carbon Bill because, as we’ve heard many times, agriculture accounts for 49 percent of our global warming emissions.

Not only does the agricultural sector provide the majority of our export earnings, it produces much of what most of us eat. But, if this Bill is to mean anything and if New Zealand as the world’s largest milk exporter is to have any credibility, now is the time to begin to put things right.

We need to understand the urgency of this.

Nitrous oxide is the most dangerous gas. Called familiarly nox, it is released naturally from soils and water. It’s also the stuff that comes from cows' pee and nitrogenous fertilisers (generically known as urea). It’s not as big a problem as methane in terms of volume – it accounts for 11 percent of our gross emissions whereas methane is a huge 43 percent but as a GHG it is 310 times more powerful than carbon dioxide. Worse, it hangs around for 114 years and as it breaks down it destroys the ozone layer that protects us from sun damage.

Methane is also a much more powerful greenhouse gas than carbon dioxide. The initial warming from a pulse of methane is 120 times stronger than for the equivalent CO2. World-wide, cattle are the major source of methane with each beast producing more than six times the methane of a sheep. The gas’s only redeeming factor is its shorter lifespan of about 12 years.

A report from the NZ Institute of Economic Research suggests, or maybe recommends, that we reduce methane to 55% of current levels by 2050 – the crucial date for reaching zero carbon according to the Bill. How to do this is the big question. Until there are practical cost effective methods of limiting the flatulence of cattle, the answer inevitably involves reducing stocking rates and stricter management of fertilisers.

Simon Upton, Parliamentary Commissioner for the Environment, has this comment: “There is no easy way to answer how much warming from a short-lived gas like methane we can afford to live with, whereas it is clear that we cannot live with the ongoing accumulation of long-lived gases such as carbon dioxide and nitrous oxide if we are to have any chance of putting a ceiling on temperature increases.”

Would we feel differently about the changes in land use in the Mackenzie Basin if the conversion was to horticulture or cropping? Maybe. Growing plants would still require irrigation and drastically change the landscape. But we would at least be providing food for an increasing population without contributing to global warming.

New Zealand has a profile on some platforms of the world stage out of proportion to our minute size. This is not only thanks to the All Blacks. We are efficient producers of animal-derived food which we export to many countries. But acceptance of the need to change the way much of the world eats is insidiously infiltrating the mainstream and must therefore ultimately have economic effects.

The health benefits of reducing meat in our diets have been emphasised ad nauseam. The next stage is to answer the question of how we can continue to feed eight billion people on diminishing arable land. Environmentalists and deep ecologists have known the answer for decades and it has now been comprehensively laid out in an article in the magazine Science, published in February. Scientists have undertaken what they describe as the first global-scale analysis of national food systems involving 156 countries.

Briefly, it shows that animal farming uses more than 80 percent of the world’s available agricultural land but provides less than 20 percent of the calories people need. There is something fundamentally inconsistent about growing food to feed animals in order to feed people – such as soya beans in Argentina when these are a good protein source and form the basis of many diets in the East.

Irreplaceable environments and their biodiversity are often destroyed in this way.

The Simons Pass station claims with pride that it will be self-contained, producing all its own stock, including 1000 to 1500 replacement dairy and 4000 beef animals a year. It will also produce all its own feed on the irrigated land.

How much better does that make this operation? Where will it, and other equivalent enterprises, be in 2050?

We will await with interest the recommendations of the Climate Change Commission, the independent advisory panel the Government is yet to appoint.

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