Climate Change Minister James Shaw has rejected a claim in a new report that the way methane is calculated disproportionately burdens the livestock industry, countering that the sector actually needs to do more to reduce emissions.
“Agricultural emissions are not priced at all, whereas every other sector of the economy faces a price of approximately $70/tonne for their carbon dioxide emissions,” Shaw said.
Changes to the Emissions Trading Scheme and other policies mean emissions in the energy and transport sectors have started falling.
“If anything, other sectors of the economy have been asked to do the heavy lifting to compensate for the lack of action on agricultural emissions,” he said.
A report released last week by scientists at the universities of Oxford and Cranfield said that to meet the Paris Agreement’s goal of limiting warming to below 2degC, using a metric that measures the contribution of each gas to warming relative to that threshold more accurately represents progress towards meeting the target.
Shaw said every tonne of methane emitted contributes to global warming.
“In the short term, methane has a far more powerful effect on global warming than carbon dioxide, so it is incorrect to draw the conclusion that methane doesn’t matter – particularly as the world is already very near the 1.5degC threshold and the warming effect of the different greenhouse gases will matter enormously in the next few years.”
He said input from Oxford University’s Myles Allen, one of the authors of the report, was why the government adopted a split-gas approach to emissions targets in the Zero Carbon Act.
However, under the United Nations’ Framework Convention on Climate Change and the Paris Agreement, New Zealand is required to use the 100-year time-horizon global warming potential (GWP-100) metric, which aggregates all gases together to obtain total emission estimates.
Agriculture Minister Damien O’Connor said the debate is actually about whether to reduce the warming effect that’s accumulated or to stay where we are.
“I believe our sector will be able to meet its targets through the investments being made into new tools,” he said.
“The pricing system we are establishing will ensure the levy from farmers is invested for farmers to get those tools as soon as possible.”
The methane study was commissioned by Beef + Lamb New Zealand (BLNZ), DairyNZ and Federated Farmers.
It found a 10% reduction in methane in NZ by 2030 and 47% by 2050 combined with linear reductions to net zero in carbon dioxide and nitrous oxide emissions by 2050, would essentially offset all future additional warming in NZ from CO2 and nitrous oxide.
This would bring NZ’s cumulative warming back to 2022 levels by 2050, effectively causing net zero warming over that period.
Under the same scenario, a 24% reduction in methane by 2050 would mean NZ achieved net zero additional warming between 2027 and 2050, assuming the rest of the world pursued current climate change policies.
In both cases, the authors noted that NZ’s total contribution to global warming would peak in the mid-to late-2030s due to the combination of CO2, nitrous oxide and methane reductions.