New Zealand risks joining the "camp of climate denialists" with a massive bill for emissions at an international level, Green Party co-leader Chloe Swarbrick says.
Farmers have been given more time before they have to start paying for emissions, and the coalition has replaced He Waka Eke Noa with another working group.
Farming needed to be de-intensified to meet climate change commitments, Swarbrick told Morning Report.
The farming sector needed to "focus on quality over quantity".
"The science does tell us that we do need to de-intensify."
New Zealand had the the second highest levels of emissions to a GDP unit, Swarbrick said citing a 2017 report on the OECD,
"and we also have massive issues when it comes to the strain on our freshwater".
"The further that we kick this can down the road, the more that we delay action, we basically end up in the camp of climate denialists and we end up on the hook internationally for a massive bill."
Swarbrick said the government was also conflating information around targets, which the Climate Change Commission has already charged with.
"But the government has decided to do its own ministerial inquiry or kind of working group to effectively either duplicate or set up a smokescreen for them to move into that pseudo-scientific target of no additional warming," Swarbrick said.
Biogenic methane emissions will be priced by 2030, Agriculture Minister Todd McClay said, despite its removal from the Emissions Trading Scheme.
"The previous government set a target of a 24 to 47 percent reduction in methane from agriculture, which is a very wide band. It's not a target," McClay told Morning Report.
"So we campaigned on an independent review of the science and targets of methane against additional warming - that's under way, that will inform that target."
But the science of methane was already settled, the Parliamentary Commissioner for the Environment said in April.
It said the real debate was not the science, but what was fair for farmers to do - and that was a question for politicians to solve.
McClay said an on-farm measurement system would be in place by 2025.
It throws out years of work but McClay said it was the last government's fault for failing to make progress and losing consensus with the working group.
A new working group would focus on pastoral sector leaders, he said.
It was not a duplication of efforts, McClay said, but if it were, "by the end of the year we'll have ended right in the same place".
He said farmers accepted their climate obligations to reduce emissions and meet the net zero target by 2050.
But that could mean consumers would have to pick up higher costs for energy, electricity, transport, because those sectors would have to bear a bigger burden of the emissions reductions required to meet the Paris targets.
"It's not that farmers have been given more time, they will pay for their contribution to warming.
"Everybody should pay their fair share and farmers will be asked to do the same."
Farmers welcome $400m investment
"Farmers are going to meet their emissions targets without the need for pricing," Federated Farmers president Wayne Langford.
He told Morning Report He Waka Eke Noa focused too much on pricing, and the issue was about finding ways to reduce emissions.
"We're already on good track [to meet targets]," Langford said.
"We're actually doing it because that's what our markets are asking for, not because we need regulation to push us there and that's probably exactly where we want to be."
The coalition will also invest $400 million over the next four years to "accelerate the commercialisation" of tools and technology to reduce on-farm emissions.
"We're paying our fair share with all the products and services that come on to farm and then with everything that leaves our farm as well. We're paying our fair share of the ETS," Langford said.
He said farmers deserved tax relief considering how much the agriculture sector contributed to the economy.
Hipkins unsure how 'exactly' to reduce emissions
Labour leader Chis Hipkins wouldn't commit to restoring the climate change policies the coalition government is backtracking on.
He told Morning Report he wouldn't determine Labour's policy for next election yet, saying more could change in the next two years.
But he said on-farm emissions must be reduced.
"It's not just because of the imperative around reducing emissions for meeting our climate change targets, it's also because international consumers are demanding that of us now.
"I think we do need to make sure we're reducing emissions, I'm not going to specify exactly how we would do that in government at this point because as I said, a lot can change in two years."