Paris climate talks: NZ agricultural greenhouse gas emissions a tough nut to crack
It is a sign of the times that cabinet ministers are getting animated about the contents of cows' intestines.
It's early evening at the Beehive, and Climate Change Minister Tim Groser is still getting over a bug he picked up a plane. But that doesn't stop him getting excited about a paper he has delivered to Cabinet.
"Listen to this – what we have learned is that rumen microbial populations are essentially the same worldwide and a technology developed in one country is highly like to work elsewhere."
He is talking about the potential for a vaccine to reduce methane emissions from cattle, which as he rightly points out is "a big issue".
Agriculture is responsible for producing 48 per cent of New Zealand's carbon emissions, according to the Environment Ministry.
Landcare Research estimates almost two thirds of that is methane produced by belching and farting cattle and sheep.
The Crown Research Institute estimates those methane emissions have increased 10 per cent since 1990 as more farms have converted to dairy.
It is the biggest blot on New Zealand's checkered climate change record.
On a per-capita basis, the New Zealand economy has the ignominy of the highest methane emissions in the world at 600 kilograms per person – six times the global average.
Such statistics raise the question of whether New Zealand can slash its emissions without crippling its biggest export industries, and if it couldn't would that still be a good idea?
Does science have the answer?
The New Zealand Agricultural Greenhouse Gas Centre in Palmerston North estimates the level of emissions needed to produce each kilo of meat or litre of milk has fallen 1 per cent a year for at least the past 20 years.
That's largely a spin-off from the genetic efficiencies farmers have been relentlessly pursuing to maximise production from their herds.
Groser says the Government has got "insufficient political credit" for establishing the centre, which since 2009 has been conducting experiments on the small steps farmers can take to reduce emissions without completely changing their livelihoods.
One simple idea that may have some potential is to breed animals to select for those that produce less methane, in the same way cattle are now bred for their milk yields or the quality of their meat.
Kiwi scientists have found young sheep on the same pasture can emit an average of anywhere between nine grams and 35g of methane per day, while daily emissions from cows can vary between 284g and 427g.
"Such large differences between animals … could potentially be exploited as an emissions mitigation strategy," Landcare says.
Other measures that the Agricultural Greenhouse Gas Research Centre is looking into range from improved feeding regimes through to the anti-methane vaccine that is exciting Groser.
But Federated Farmers climate change spokesman Anders Crofoot is not expecting imminent breakthroughs.
It may not be possible to breed low-emission sheep and cattle. Although methane emissions from individual animals vary, Crofoot says those variations are not highly hereditary. He also suggests a vaccine, if it can be developed, might only prove "one of the many tools in the toolkit".
"It is the sort of thing that has potential but it is still years away".
Rather us than them
But Crofoot argues that if New Zealand cut back on dairy and red meat production, those products would just be produced less efficiently overseas, resulting in more greenhouse gas emissions, not less.
"From all the studies that have been done, New Zealand is a very efficient producer," he says. "Even if you take into account shipping food halfway across the world using fossil fuels, we still come out better."
Nor does he believe a shift to vegetarianism within New Zealand would necessarily help in the battle against climate change.
About half of our meat is produced on hill country, he says.
Replacing that with horticulture, potentially on deforested flat land, could increase emissions, especially if that involved the use of commercial fertilisers which are the source of another potent greenhouse gas – nitrous oxide.
"We are basically taking a resource that can't be consumed any other way and producing something humans can eat," he says of the meat industry.
Sweating over palm kernels
But Greenpeace executive director Russel Norman argues Crofoot's claim that the dairy industry is an "efficient producer" is a myth.
That is once farmers' reliance on foreign-grown palm kernel expeller (PKE) as a supplementary food source for cattle is taken into account, he says.
Last year, New Zealand imported 2.2 million tonnes of PKE – about 30 per cent of world exports – up from next to none in 2000, according to the United States Agriculture Department. To put that in some perspective, New Zealand exported 1.5 million tonnes of milk powder the same year.
The bulk of PKE comes from palm plantations in Malaysia and Indonesia, some of which have been created by the draining and burning of peatland which would otherwise be much more efficient at taking carbon out of the atmosphere.
Given that only 18 per cent of palm plantations were certified as sustainable by the Roundtable on Sustainable Palm Oil (RSPO) last year when New Zealand imported 20 per cent of global PKE production, it seems clear a sizeable volume of PKE imported into New Zealand is coming from non-certified sources.
Greenpeace commissioned a study from British-born consultant Rob Carlton, a former regulatory manager at Bayer Cropscience and Aventis, in 2011.
He estimated the impact of using PKE as supplementary food source in New Zealand was equivalent to releasing 38 to 70 grams of carbon dioxide for every litre of fresh milk produced here.
"Once you account for palm kernel everything changes and New Zealand's dairy industry has very high emissions," Norman says. "We have got to kill a lot of Indonesian forest and set it on fire in order to grow those dairy cows on palm kernel."
So where does this leave consumers?
Palm plantations produce more oil on less land than other sources of food oil.
But the demand for palm oil and byproduct PKE is increasing land pressures in some of the most valuable and vulnerable ecosystems on the planet.
Foodstuffs' own-brand Pams and "Budget" groceries contain only palm oil that is certified by the RSPO as sustainably sourced. Countdown says the same will be true of its own-brand products by the end of the year.
While that may provide some comfort to eco-shoppers, Greenpeace says certification is not proof that palm oil hasn't been produced on drained peatland or cleared forests.
People concerned by the use of PKE in the dairy industry can avoid it by buying milk from a producer that doesn't use it as a feed, such as Lewis Road Creamery, at a price.
If climate change is a factor in making you grow your own food, avoid synthetic, nitrogen-based fertilisers.
Little of that will help bring down New Zealand's stubbornly high methane emissions, but it may be good for the planet.