Sir Peter Gluckman issued a flurry of reports in his last few months as Prime Minister’s science adviser. His final report to Jacinda Ardern made some striking points about the future of farming. Eloise Gibson digested the five main issues.

Methane matters

Don’t be fooled by anyone implying that methane doesn’t matter much in the scheme of things – cutting methane is crucial to New Zealand’s efforts to slow climate change. That, in essence, was one of the key messages from Gluckman’s final report to Jacinda Ardern.

Whether to ignore, eliminate or “stabilise” methane, the single biggest climate impact from cattle farming, has been major feature of debate about New Zealand’s proposed Zero Carbon Bill.

As Gluckman points out, our proposed bill is modelled on a British law that mostly only had to deal with fossil fuels. Here in New Zealand, our emissions are skewed to harder-to-cut sources like animal burps and urine. We can reduce cows, plant forests, or hope for technical break-throughs, but we can’t, as the UK can, make major gains merely by replacing our dirty power stations.

The Government mooted three paths to 2050: reducing all gases to net zero, reducing CO2 to net zero and “stabilising” methane, or setting no goal at all for methane. The discussion document did not say at what level methane might be stabilised, leaving something of a void.

Into that void came a report last month commissioned by the Parliamentary Commissioner for the Environment, Simon Upton. Calculations by greenhouse expert Andy Reisinger found that if New Zealand shaved 10-22 percent off its methane emissions by 2050, and shrunk them by 20-27 percent by 2100, our livestock burps would no longer be adding new heat to the climate.

People debated whether those figures counted as good or bad news, and, more fundamentally, whether ‘not further worsening’ climate change with methane was ambitious enough.

Methane has contributed 40 percent of total global warming since 1750, and it is the gas that has contributed most to farming’s increasing emissions since 1990.

In his final report, Gluckman’s message seemed to be to avoid get sidetracked by technical arguments, and get on with curbing methane.

There’s been a long (some would say interminable) debate about the importance of “stock” (long-lived) gases (like CO2) versus “flow” pollutants (like methane), to which he added this: “Describing methane as a ‘flow pollutant’ does not imply that it moves through the atmosphere without causing permanent climate effects, though the effects are different from those of CO2. Methane is a very potent warming agent in the short-term, so it is contributing significantly to current warming trends … Although methane does not accumulate in the atmosphere like CO2 does, it has potent effects on near-term warming, and this potency increases with increasing rates of methane emissions over time.”

His big point was that cutting methane quickly buys the planet time: “While noting that methane emissions from agriculture cannot, and need not be, reduced to zero, reducing global methane emissions quickly will [reduce] the peak warming temperature and the rate at which CO2 emissions need to be reduced …The delay will allow more time to bring direct CO2 emissions to net zero.”

He sees another bonus, too: giving our products a marketing edge: “There are many reasons to act aggressively to reduce [livestock] emissions. This goes beyond arguments of short-lived versus long-lived gases; there are also strong market and reputational reasons for driving down agricultural emissions while making farms more efficient and sustainable,” he said.

“There is a growing market for products that can be verified as having a low-emissions footprint, upon which New Zealand’s agricultural exports can capitalise.”

We don’t have a good way to measure farmers’ efforts

This is the stark reality for anyone trying to claim credit for cutting greenhouse gases: if you can’t measure it, it didn’t happen.

Even nations’ governments must stick to a complex set of mutually-agreed measuring techniques when they report their yearly emissions to other countries.

But neither the modelling tool Overseer, which many farmers are already using, nor any other tool we currently have is up to the job of telling us accurately how well farmers are cutting emissions, Gluckman says.

New Zealand farmers need something better and more comprehensive – ideally a single reporting system that incorporates water quality, animal welfare and other measures in the same tool, he says.

“Unfortunately, there is no reliable way to directly and accurately measure emissions from an individual farm, although proxy estimates can be generated by modelling inputs and outputs on the farm,” he says. “A key decision that will need to be made is whether to try and manage GHG production from farms with a direct priced-based system based on some estimate of GHG emissions at an individual farm basis or at the level of a consolidator (e.g. a milk company … or to use some other approach such as a farm-plan.”

His pick is individual farm plans, albeit a considerably beefed-up version from the ones dairy groups are already working on implementing.

Overseer, which many regional councils rely on for estimating fertiliser run-off from farms, varies in its application between councils and has been controversial. Although the tool has been changed to include modelling of greenhouse gases, Gluckman says it may not work on complex farms and might not accurately estimate real gas outputs.

The comprehensive farm plans he has in mind would be devised by specially-trained advisers, and could incorporate bits that work from Overseer, lifecycle analyses of carbon footprints and other tools. They’d show farmers the first priorities to cut emissions on their farm, track trends as well as total emissions, and bring in as many as possible optional ways of cutting gases.

Gluckman notes we’d need an army of trained advisers, and they’d need to be regulated. It could be expensive.

“Many farm advisors at present will not have, and cannot be expected to have, the knowledge base to be effective in this regard,” he says. “A consideration here is recognition of the cost of training a suitable number of specialist farm advisors who can propose effective … mitigation strategies…There will also be a need for Government to audit/regulate these advisors.”

We need to talk about changing land use … and GMOs

The report doesn’t address the vexed question of how many cows the county can sustain, long-term, at least not to the extent of trying to estimate a number. But it does raise bigger questions about the future of New Zealand farming.

The Government’s Biological Emissions Reference Group (BERG) is working on a major report on animal emissions, due soon, but the early modelling supplied to Gluckman’s office suggests that farm management practices that could be employed right now might reduce animal emissions somewhere between 2 and 10 per cent. That might include better breeding, precision fertiliser-use, and other measures largely aimed at raising efficiency so farms can produce more meat and milk for their gas output.

Long-term, those kinds of measures won’t be enough, meaning game-changing new technologies or big changes to our land use, or both, will likely be needed, Gluckman’s report says “BERG’s modelling suggests that the gains that are possible using existing strategies are likely to make only small (less than 10 percent) reductions in our total agricultural emission equation without significant afforestation, a reduction in stock numbers, or other changes in land use,” says the report.

Farmers could consider diversifying into forestry or making money from other crops, says Gluckman. “Pastoral agriculture competes for land use with forestry, which serves as a carbon sink …. Arable farming and horticulture are much less GHG intensive than pastoral farming, and therefore represent an emissions-reducing alternative land use within the primary sector, including as a diversification strategy within a livestock farm enterprise.”

But: “For larger reductions from the primary sector, technological innovations will be needed,” he says.

This leads him to prod the Government to revisit our national feelings about genetic technologies such as transgenic, low-methane grasses for cows to eat, trees with enhanced carbon sequestration, and other potentially controversial crops that could turn a profit on what is now livestock-farming land.

“The increasing global interest in plant- based milks and meats may offer opportunities for diversification, but the challenge will be to achieve economic returns to the farmer. This is less likely unless new plant breeding techniques – for which social license remains highly uncertain and controversial – are used,” he says.

“New Zealand scientists have developed promising forages using genetic technologies that could be used to make major progress through higher energy, lipid rich ryegrasses which are now in field trials in the United States. However, these have not been and effectively cannot be subjected to field testing in New Zealand … The inability to assess these technologies in New Zealand conditions may be to our long-term disadvantage.”

The New Zealand-developed, US-tested grass might cut methane by up to 20 percent per farm, Gluckman notes, although perhaps the gain would not be that high across all farms.

He urged Ardern to weigh up these genetic technologies alongside other big possible changes – namely significant cuts in cow numbers and investing in carbon offsets – to decide how to get the reductions we need.

Technology is still a wild card

Genetic technology aside, work is underway on other hopeful gas-shrinking technologies, like conventional breeding of low-methane and low-nitrogen animals, nitrogen-cutting pasture species, such as plantain, and greenhouse gas-reducing feed additives for animals.

New Zealand, more than almost any other country, has invested significant government money in funding scientists to explore technical solutions to emissions from animals’ bodies.

So far, nothing has made it to market – apart from a nitrous-oxide reducer called DCD, which was withdrawn almost as quickly as it entered our paddocks after traces showed up in milk.

Globally, the methane-cutting product that is closest to reaching the market is not from around here: it’s a Dutch methane inhibitor called 3-nitrooxypropanol (3NOP), which has shown considerable promise in feedlot farms overseas, where it cuts methane burped by about a third, on average. Before it could be used here, scientists need to find a way to get it into New Zealand’s grazing animals, such as a long-acting or slow-release formulation (perhaps a tasty pill a cow could munch on her way to each milking). “New Zealand has the skills to develop such a formulation, but there is also a need to be able to manufacture large amounts of the compound, which would require significant capital investment and would itself have a carbon footprint,” says Gluckman’s report.

The holy grail – still being sought by AgResearch scientists at Palmerston North – remains a methane-inhibiting vaccine, which could theoretically work on all ruminant livestock (dairy, beef, lamb, goats) to shrink emissions after a single injection. It’s yet to be proven to work on live animals, though, with Gluckman calling progress on the vaccine “somewhat disappointing”.

Leaving methane aside, a number of fertiliser-type products and plant species are being tried that could stop nitrous oxide – the next most prevalent greenhouse gas that farms make, after methane – from leaking to the atmosphere. DCD failed, but others look likely to take its place.

Gluckman’s report says these technologies are worth pursuing in the medium-term, but doesn’t pin hopes on them to solve the problem alone.

This is New Zealand’s best chance to make a difference to global emissions

A zero-emissions car is possible, but not, at this stage, a zero-emissions cow. The report says farming is going to make greenhouse gases – but by showing other countries we can seriously reduce them, we can be a world leader.

“The reality is that there are no ‘zero emissions’ technologies available for pastoral agriculture, so eliminating these emissions completely is not feasible, but reductions are both possible and consequential,” says Gluckman’s parting report.

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