Dr Jacqueline Rowarth: Lessons learned from Cyclone Gabrielle

Foresty slash and debris from the apple industry at the mouth of the Esk River in Hawke's Bay. Photo / Warren Buckland

Opinion: The devastation caused by Cyclone Gabrielle has highlighted the unintended consequences of several policies that affect rural New Zealand.

Unintended consequences are a fact of life.

Parents try to think through what might happen to their children trying something new, based on their own experience, that of other parents, and perhaps some reading around the subject.

Medical professionals consider drug interactions before prescribing, and scientists and engineers calculate the domino effects of a change.

Policy analysts work similarly.

In all cases, the aim is to improve an outcome without creating a worse problem elsewhere. But nobody can foresee every eventuality that might occur. This is particularly the case if they aren’t experts in the discipline being considered.

In the aftermath of the recent cyclones, we can see the unintended effects of several policies.

Areas have been devastated by floods and slash because the ETS and carbon credit settings for fast-growing trees globally appear to be more lucrative than farming sheep and beef.

Regulations around forestry harvesting have been less stringent than those that now exist in other countries.

The cost of transport of logs as well as of slash (waste material) out of the forest and to areas where it can be used remains a major hurdle in New Zealand.

Now we see that the cost of not removing the slash can have a very high price in terms of human suffering and, indeed, life.

Leaving the forests standing has apparently been the plan of some overseas companies (another policy has meant that they have been allowed to invest without going through the Overseas Investment Office) but as they mature and fall down, or if knocked down by the wind, they could cause the same sort of problem as seen recently.

Yet another signal to farmers to consider afforestation has been the greenhouse gas and He Waka Eke Noa initiative – a levy on ruminant greenhouse gases (GHG).

The levy will encourage farmers to reduce GHG through efficiency and the adoption of new technologies (when they become available).

Theories that we no longer need animals and should, instead, be concentrating on plant-based and cultured protein, need testing with more rigour than so-far applied.

The science around human nutrition and the complete life-cycle analysis does not support the theories.

The first problem is considering protein not essential amino acids (EAA), the components of protein, which must be supplied from what we eat because the human body lacks the metabolic pathways required to synthesize them.

Complete proteins contain all the EAA and are usually derived from animal-based sources of nutrition. EAA are also available from incomplete proteins, which are usually plant-based foods.

Dr Jacqueline Rowarth. Photo / Supplied

In obtaining the EAA ratios required for the body, amino acids in the diet not required are broken down for energy and the nitrogen in the amino acids is excreted.

The result is nitrous oxides generated in the sewerage system – and nitrous oxide is a long-lived GHG.

Researchers have calculated that “removing animals from US agriculture would reduce agricultural GHG emissions, but would also create a food supply incapable of supporting the US population’s nutritional requirements”.

The modelled plants-only agriculture produced 23 per cent more food, but compared with systems with animals, diets in the plants-only systems had greater excess of dietary energy (people had to eat more calories than they needed and so would gain weight) and resulting in a greater number of deficiencies in essential nutrients.

Investigation into cultured protein is similarly fraught with complications. In particular, confusion around where to start the calculations is apparent.

Perfect Day, which cultures cow-free whey protein, examines the fermentation process from the vat onwards but includes none of the growing processes for the ingredients needed for the vats.

This includes the energy source for the fermentation, the sugar (from cane, corn or beet), which requires land and agrichemicals and harvesting.

In considerable contrast, the starting point for the comparison with a pasture-based dairy was the grass being fertilised and the cow being milked and then the milk being taken to the processor.

Moving on from these arguments, the cyclone havoc has shown the importance of treating New Zealand’s soils, all of which are recent in geological timeframes, carefully.

Permanent cover is important, and the protection of native forests was removed by various waves of newcomers to the land.

Listen to Jamie Mackay interview Dr Jacqueline Rowarth on The Country below:

Agricultural scientists and farmers have reduced the area of erosion-prone land since the 1940s by overcoming nutrient limitations and establishing improved pasture species with deeper rooting systems.

Permanent pasture offers protection. Poplars and willows have also played a part. But in torrential downpours, nothing can hold fragile slopes.

The nature of our soils and the ongoing tectonic uplift means that they have underlying instability.

Plant-based agriculture is not suitable for most of New Zealand for reasons of the basic soils, topography and climate.

Plant-only diets are not suitable for human health.

Cultured protein requires sugar crops that New Zealand can’t produce.

But New Zealand does produce the animal protein important for human health with least environmental impact.

The key for the future will be preventing the implementation of more policies to fix the old ones before their own set of potential unintended consequences has been investigated by experts in the underlying disciplines involved.

The forestry slash inquiry is just the start of what is required for New Zealand’s recovery.

- Dr Jacqueline Rowarth, Adjunct Professor Lincoln University, is a director of DairyNZ, Deer Industry New Zealand and Ravensdown. The analysis and conclusions above are her own. jsrowarth@gmail.com