Parliamentary Commissioner for the Environment Simon Upton's report on methane emissions — which is in the form of a 'note' by Dr Andy Reisinger of the New Zealand Agricultural Greenhouse Gas Research Centre — confirms how confused scientists are about methane and its impact on global warming, says Pastural Farming Climate Research Inc chairman Robin Grieve, of Poroti.
While environmental groups reject Grieve's argument outright, he is adamant the Government has no option but to pull methane emissions out of the Carbon Zero Bill.
"Report after report has debunked the validity of the system our politicians use to quantify methane and the latest 'note' is just one more," he says. "It is a modelling exercise rather than scientific research and it is consistent with most recent reports in finding livestock emissions of methane do not need to be eliminated in the same way CO2 emissions do.
"This means the politicians have to rethink how methane emissions are treated and dump the current system of carbon accounting which does not differentiate between short lived and long lived emissions and is simply without credibility."
'Report after report has debunked the validity of the system our politicians use to quantify methane and the latest 'note' is just one more. It is a modelling exercise rather than scientific research ...'
Dr Reisinger's note shed little light on defining a correct treatment of livestock emissions, Grieve says.
"He confirms atmospheric methane will not increase once methane emissions are stable, but suggests indirect effects of methane will cause further warming.
"This is highly contentious and Simon Upton has indicated he has released this modelling report to contribute to the scientific debate. This invites a rethink and an analysis of what is known and not known about methane."
Methane 'not benign'
However, Forest & Bird climate advocate Adelia Hallett says methane is not the benign gas some are trying to paint it as. and research from the Parliamentary Commissioner for the Environment shows cutting methane emissions is essential to keeping global warming under control.
'Methane is a powerful greenhouse gas — 33 times more powerful than carbon dioxide ... New Zealand's native species are already feeling the impacts of climate change, and face extinction if we don't act fast.'
Simon Upton's report found that if New Zealand wanted to ensure that methane from livestock caused no additional warming beyond the current (2016) level, emissions would need to reduce by at least 10-22 per cent by 2050, and at least 20-27 per cent by 2100.
Methane makes up 43 per cent (33.36 million tonnes) of New Zealand's annual greenhouse gas emissions, with 86 per cent of that methane coming from agriculture, mainly from livestock.
"Methane is a powerful greenhouse gas — 33 times more powerful than carbon dioxide [over a century]. The fact that it stays in the atmosphere for less time than carbon dioxide does has prompted some to claim that merely 'stabilising' emissions at current rates is good enough." Hallett says.
"New Zealand's native species are already feeling the impacts of climate change, and face extinction if we don't act fast.
"We need to keep global warming to no more than 1.5 degrees, and that means making big cuts in greenhouse gas emissions within the next decade. Cutting methane is a major part of that."
Greenpeace sustainable agriculture campaigner Gen Toop also says the science is clear that New Zealand must urgently and substantially reduce methane emissions from livestock.
"The explosion in cow numbers in recent decades has always been New Zealand's elephant in the room when it comes to taking action on climate change," she says.
"The simple truth is there are already too many cows for our climate to cope with, yet the Government is still allowing dairy conversions to continue — even in fragile and unique places like the MacKenzie country."