A principal analyst for the Climate Change Commission told a public webinar that more needs to be done to reduce agricultural emissions or the country will miss its methane targets, Marc Daalder reports

New Zealand is on track to miss its targets for reducing methane emissions, according to the Climate Change Commission.

Sally Garden, a principal analyst for the Commission, told a public Zoom webinar that we would fail to meet our goal – of reducing methane emissions by 10 percent by 2030 and by 24 to 47 percent by 2050 – if we continued on our current trajectory.

“There’s been about a 20 percent improvement in emissions efficiency since 1990. Based on analysis, we do expect those improvements to continue, but they will slow down. Our analysis shows that that improvement does need to be accelerated. If more is not done to reduce emissions from agriculture, then we won’t be able to meet our methane targets,” she said.

Garden also said emissions of nitrous oxide from agriculture were a concern.

“Agriculture accounts for about 88 percent of New Zealand’s methane emissions and [with nitrous oxide] it accounts for 18 percent of long-lived gas emission.”

Garden said there were two approaches to reducing agricultural emissions.

“The first one is around adjusting farm management and the second one is around the use of specific technologies to reduce emissions,” she said.

Farm management practices like reducing livestock numbers, reducing the amount of feed used or abandoning the use of synthetic nitrogen-based fertilisers could all make a difference.

“You can’t look at each one in isolation. Farms are very complex systems where all these things interact. Changing one thing can have an impact on another part of the farm system so we need to look at these as a whole farm management package.”

Garden cited the Biological Emissions Reference Group (BERG) established under the previous National-led government, which found existing farm management practices could reduce agricultural emissions by around 10 percent.

“However, the ability of farmers to implement such practices varies widely, and while some farmers might achieve such reductions without significant negative impacts on profitability, for others the impact could be large,” the group’s final report warned.

Further emissions reductions would likely require land use change, the BERG report found. Additional changes to farm management and land use aimed at protecting freshwater quality could reduce emissions another 4 percent – a finding validated by the Government’s estimate that freshwater reforms could reduce emissions by as much as 90 million tonnes by 2050.

Garden said there was “a lot of uncertainty” around technological solutions to enteric methane emissions. She cited the methane vaccine and methane inhibitors – such as Asparagopsis seaweed – as examples of new technologies with potential.

“As I mentioned, there’s a lot of uncertainty around when and if these sort of technologies might come to fruition and also, you won’t be able to just add them all up to get more and more gains, because some of these technologies will work through the same mechanisms,” she said.

When fed to cattle, Asparagopsis can reduce methane emissions by more than 90 percent, researchers say. Photo: Marc Daalder

“Collectively, if these technologies are developed, we estimate they could reduce [methane] emissions by around 30 percent.”

Garden warned that “if new technologies don’t come to fruition, then we’d likely need to see more land use change into other, lower emissions uses like horticulture or forestry”.

Analysts working on reducing emissions in other sectors of the economy also spoke at the webinar. Alexandra Aimer-Seton outlined the situation in transport and said most of the solutions to transport emissions were already known.

“There are many opportunities – and most of those exist now – to reduce emissions in transport,” she said.

“By switching to electric vehicles, road transport – including heavy vehicles – can be almost decarbonised by 2050. This requires a rapid increase in EV sales so that nearly all vehicles entering our fleet are electric by 2035. I also need to emphasise that electric vehicles are an important piece of the puzzle but that does not take away from how important it is to reduce emissions from other areas of transport and to give New Zealanders choice in how they reduce their emissions.”

Aimer-Seton said reducing the number of the cars on the road would be key, both by providing alternatives in mass transit and active transport (walking and cycling) but also by “designing compact communities where the necessary infrastructure makes it easy and safe to get around”.

Marc Daalder is a senior political reporter based in Wellington who covers climate change, health, energy and violent extremism. Twitter/Bluesky: @marcdaalder

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