It is not exactly glamorous work. Measuring sheep farts is smelly, time consuming and expensive.

But for Dr Suzanne Rowe, a scientist who is breeding strains of sheep that emit less methane than regular flocks, there is nothing more important she feels she could be doing.

“New Zealand has really become a global leader in this space and there’s a lot of buzz around at the moment – it’s hugely exciting,” she says.

The release of methane gas from New Zealand sheep and cattle accounts for one third of the country’s greenhouse gas emissions, the single largest contributor in the country.

Since 1990, methane gas from stock has increased by 10%, according to the ministry of the environment, along with a 70% increase in dairy cattle and a 44% drop in sheep numbers.

Accordingly, methane has found itself in the crosshairs of the government’s climate action policy, and scientists around the country are being given the green light to run free with their best and brightest ideas to lower emissions.

Sheep on a hill in Golden Bay, South Island. Photograph: Adam Foster/GuardianWitness

Agriculture ‘must be part of the solution’

In November, the prime minister, Jacinda Ardern, pushed the Zero Carbon Act through parliament with cross-party support, saying the world was “undeniably warming” and all greenhouse gases must be reduced to net zero by 2050 in order to honour agreements made under the Paris climate accords.

“We have to start moving beyond targets,” Ardern said. “We have to start moving beyond aspiration. We have to start moving beyond hope and deliver signs of action.”

Under the zero carbon legislation, the methane targets are separated out from other greenhouse gases, with the goal of reducing biogenic methane by 10% by 2030, and 24-47% by 2050.

“Agriculture is incredibly important to New Zealand,” she said. “But it also needs to be part of the solution. That is why we have listened to the science and also heard the industry and created a specific target for biogenic methane.”

In Nelson, at the top of the South Island, the Cawthron Institute has recently been awarded government funding to cultivate and research a red native seaweed known as Asparagopsis armata.

The agriculture minister, Damien O’Connor, has said if this seaweed is able to be mass produced, it could be a “game-changer for farmers here and around the world” as it has been proven to reduce stock methane emissions by as much as 80% when added as a feed supplement at quantities as low as 2%.

“The holy grail is going to be getting enough of the stuff,” Cawthron chief executive Prof Charles Eason told the Guardian. “It’s got a complicated life cycle. One of the barriers to getting this to market is growing enough of the stuff in ways that are cost effective to make it commercially viable.”

Asparagopsis armata at the Cawthron Institute. Photograph: The Cawthron Institute, supplied

O’Connor said the potential of the seaweed not only in New Zealand but around the globe was “huge”.

“Other products typically provide reductions of between 10% and 20%,” he said. “Australian research estimates that if just 10% of global ruminant producers adopted Asparagopsis as an additive to feed their livestock, it would have the same impact for our climate as removing 50 million cars from the world’s roads.”

Building cattle for a climate-altered future

Several hundred kilometres north in the Waikato city of Hamilton – the heart of dairy country – Dr Bjorn Oback from AgResearch has been given NZ$10m in government funding to design a “climate-smart cow”.

There are more cows than people in New Zealand and while they have become a mainstay of the economy they also draw the ire of environmentalists for their high emissions profile, intensive impact on the land and muddying and polluting waterwarys.

Oback says specialised breeding programmes can “take decades” to reach their desired outcome, but using genetic modification his team can design a climate-smart cow much more quickly and precisely – though the process remains controversial.

As well as working towards manipulating the genes that control methane admissions , Oback is also focused on designing cattle that will thrive in a climate-altered future – animals that are more heat tolerant, hardy and productive.

The five-year programme is only three months in, but is already targeting coat colour adapation – creating cows that are lighter in colour, making them more heat-tolerant.

An important feature of the programme was using “elite” cattle, Oback said, so not only would they emit less methane and be climate adaptive – they’d also be super performers.

“We’re taking a high-performing elite dairy background, and then we’re putting mutations on top of it.”

Oback’s work is intertwined with Rowe’s research into low emitting sheep in the south of the country. For Oback to study – and try to manipulate – the genes of low-emitting stock, he is invested in the survival of Rowe’s flocks, who are now in their third generation.

Rowe and her team’s work is creating a buzz in the agricultural community, because not only do her sheep have low methane emissions, they also produce more wool and are shown to be hardier and healthier than normal sheep. At this point no-one knowns why, but 20 major breeders have already signed on to produce flocks, and the low-emission sheep have the backing of industry body Beef and Lamb New Zealand.

Agresearch senior scientist Dr Suzanne Rowe with her portable sheep methane testing device Photograph: Agresearch, supplied

“We have demonstrated a 10% difference in methane produced between the average sheep in both the high and low methane breeding lines,” says Rowe.

“It is a very natural system, it’s been used for eons. Domestication and breeding animals is something everybody is familiar with and it’s cumulative. If you breed an animal tomorrow the affect is always there and the offspring that come after them always have that effect.”

Many of the methane reduction programmes in New Zealand are in their nascency, with climate smart cows at least five years away and the mass roll-out of Asparagopsis armata at least five to ten.

But agricultural scientists and farmers say after decades of indecision and uncertainty concrete action is finally underway in New Zealand – and it is drawing global attention.

Myles Allen is a climate change scientist at Oxford University and head of its Climate Dynamics group. He recently visited New Zealand and said he was impressed with how engaged industry leaders, government and the farming community were.

“I only wish New Zealand could convince others … to take such a sensible approach.” he said.







