Why we want fairer methane targets
COMMENT: Use the latest science when calculating greenhouse gases, say Jim van der Poel and Andrew Morrison.
Dairynz and Beef + Lamb NZ call on the Government to give farmers a fairer deal by using the latest, best science when setting methane targets. While Kiwi farmers overall are reducing emissions, agriculture is being blamed for a far bigger share of NZ'S warming than it actually causes.
It's important all sectors play their part, including agriculture, transport, energy, towns and cities.
The method the Government uses to calculate emissions data, GWP100, is accurate for carbon dioxide but hugely overstates the warming impact of methane.
Although agriculture accounts for around 50 per cent of New Zealand's emissions, it does not account for 50 per cent of the warming. That's because methane has a half-life of around 12 years so disappears from the atmosphere much faster than CO which can last up to 1000 years.
So, alongside other primary sector groups, we've written to the Government asking for all its agencies and independent bodies, such as the Climate Change Commission, to take a split-gas approach when reporting and delivering emissions budgets.
This would clearly demonstrate that short-lived gases like methane and long-lived gases like CO2 have different impacts. Perspective and sound science matter for the Government's response to climate change.
It's so important we get this right because key climate change decisions are made using that data – including methane targets that impact what farmers can do on-farm. This doesn't just affect a farm's bottom line, but also has a flow-on effect on mental health and wellbeing.
If farmers aren't able to run successful and sustainable businesses, their contribution to their families, the economy and local communities reduces — affecting the wellbeing of all New Zealand.
Also, because Kiwi dairy farmers have the lowest carbon footprint for on-farm milk and sheep and beef production for meat, there's no silver bullet to further reduce emissions. We need new technologies — and the sector is investing millions in R&D to achieve this.
The whole point of reducing emissions for international agreements is to reduce warming — so, take the right actions, it's important we have a more accurate picture of what's going on.
The Intergovernmental Panel on Climate Change confirms the way emissions are currently calculated, using GWP100, overstates the warming impact of methane by 3-4 times, when methane emissions are stable (as they are in New Zealand).
Since New Zealand's agricultural methane emissions have been stable for almost two decades, since 2005, they're not contributing additional warming each year.
A 2022 paper published in the prestigious Nature Journal by 33 scientists also highlights the need for countries to accurately consider the warming impacts of different greenhouse gases when putting forward their targets for reductions.
To address this, we want the Government to adopt a more advanced method (such as GWP*) for calculating and reporting agricultural methane emissions, in line with the recommendations of leading scientists. We want an appropriate metric that more accurately reflects the different warming impacts of short-lived and long-lived gases.
In 2019, our sector won a hardfought science-based decision with Government for a split-gas approach in the Climate Change Response Amendment Act 2019, recognising biogenic methane only needs to reduce and stabilise, not go to net-zero like long-lived gases.
We believe both the 2030 and 2050 methane targets need to be reviewed. We're listening to farmers and will ensure the latest science findings are taken into account when targets are next reviewed in 2024.
We'll advocate for targets that work for farmers in line with public and customer expectations, technology availability, the competitive market and farmers' own environmental goals. ■