A major report on climate change yesterday suggests there may be no need for panic about greenhouse gases caused by cows belching.

Though Greenpeace reacted to the report by calling for an immediate reduction in cow numbers, there are a number of other options available to respond to the report.

Those options could also provoke substantial modifications to the Emissions Trading Scheme.

The report is the first on climate change from the new Parliamentary Commissioner for the Environment, Simon Upton.

It reports on modelling by Dr Andy Reisinger of the New Zealand Agricultural Greenhouse Gas Research Centre of the impact of various reductions in methane emissions on temperature and New Zealand’s target of net zero emissions by 2050.

It will have surprised many in the agriculture sector with its advice that though methane is a short-lived gas, its impact on temperature lasts longer than thought.

The report says that if emissions from New Zealand’s livestock were held at current levels, warming caused by those emissions would increase for centuries (although at a gradually declining rate).

“While methane emissions from New Zealand’s livestock may be short-lived in the atmosphere, they are by no means benign,” it says.

If New Zealand wished to ensure that methane from livestock contributes no additional warming beyond the current level, emissions would need to be reduced by at least 10-22 per cent below 2016 levels by 2050 and 20-27 per cent by 2100.

“These ranges reflect uncertainty in future global emission trends.”


But the report does not say how to achieve that goal, and it is Upton’s policy that his office not engage in that part of the debate.

“Modelling alone cannot determine how methane should be treated when setting the country’s climate change targets,” the report says.

“That is a policy matter.

“The objective of no additional contribution to warming beyond current levels is only one possibility.”

That last sentence suggests that the debate on how to handle methane could be wide-ranging and that means it must inevitably include debate on land use strategies.

Greenpeace fastened on to this yesterday with a statement calling for a reduction in cow numbers.

“Fewer cows means fewer emissions,” said Greenpeace campaigner Gen Toop.

“The only future for farming is to diversify away from industrial livestock and take up regenerative farming methods that are good for our climate, good for our soil, and good for our rivers.”

But Upton’s reference to there being more than one possibility to reduce emissions is likely to refer to the possibility that we will end up with more than the Emissions Trading Scheme to bring about emissions reductions.

It is possible that methane may not to be brought into the ETS and that some other regime may be implemented to bring about the reduction proposed in the Upton report.

National’s climate change spokesperson, Todd Muller, said he thought the report challenged the idea that the ETS would be the sole instrument to bring about emission reduction.

“But I don’t think it necessarily challenges the ETS as having a place within the suite of tools that might be available to any government in terms of responding to climate change,” he said.

However Federated Farmers, in a statement that was much less negative than some had feared, said the scenario outlined in Upton’s report would have a significant impact on New Zealand’s primary export earnings if pursued.

“The paper acknowledges that through breeding more efficient animals and improvements in farm management, the emissions intensity of New Zealand agricultural production has improved by about one per cent per year over the last few decades,” said Climate Change spokesperson Andrew Hoggard.

“This highlights the importance of the ongoing work by researchers, and by farmers relentlessly pursuing efficiency gains.”

But Hoggard’s point remains; stabilising methane emissions is likely to have profound economic consequences inflamed by the fact that to stabilise methane emissions where they are now would require almost immediate steep reductions because of the time lag between reduction of emissions and the impact of that reduction.

However, Upton says that an objective of no additional contribution to warming from livestock methane is just one possibility.

“Different objectives could lead to quite different emphasis being placed on reducing methane emissions.

“One objective, for instance, might be to consider minimising future total warming from all greenhouse gas emissions.”

This will be the kind of decision that the proposed Climate Change Commission might deal with.

But it would also be highly political because of the likelihood that it would pitch farmers, the transport industry, industry and even, possibly, forestry, all against each other competing to preserve the least possible reduction in emissions for their industry or activity.

That is why consideration of the role of the Emissions Trading Scheme will also have to be part of the debate.