"Prime Minister Jacinda Adern must realise that a government cannot just make stuff up and scaremonger like this. There must be some regard for the truth by her and her ministers, and on this occasion there is none."
Mr Grieve said the Ministry for the Environment report New Zealand's Environmental Reporting Series: Our atmosphere and climate 2017 reported data collected all over New Zealand between 1960 and 2016 which showed a significant reduction in extreme wind events and a small decrease in extreme flooding events over that period.
"The statistics and data do not back up the desperate claims that we are experiencing more extreme weather events. We are experiencing less in fact despite one degree of warming.
"Claims also that the one degree of warming has been caused by increasing greenhouse gas emissions are also inaccurate with the Intergovernmental Panel on Climate Change (IPCC) itself attributing only 0.2 degrees of that increase to greenhouse gas emissions.
"The Government is off to a poor start if it has to exploit people and scaremonger on an issue that deserves some integrity."
Responding to Mr Grieve's comments, Mr Shaw says in a statement as Green Party co-leader — his role as author of the fundraising email — that the science around climate change is settled, and has been for some time.
"Evidence is clear that climate change will lead to more frequent and more severe extreme weather events," he says.
"Last year I released the Climate Change Adaptation Technical Working Group's Stocktake report, which summarises how our climate is already changing, and the Coastal Hazards and Climate Change guidance, to assist councils and communities to plan for the effects of climate change.
"I welcome discussion and debate about how New Zealand can best play its part in the global effort to reduce climate pollution, help ensure a stable climate for generations to come, and create new jobs in clean industries.
"The creation of an independent Climate Commission and the Zero Carbon Act, both of which were announced at the end of 2017, are critical parts to that goal."
Mostly harmless claim rebutted
In June last year, the Advocate reported that Pastural Farming Climate Research Inc (PFCR) had produced a report claiming to confirm livestock emissions of methane were not causing global warming.
Its chairman Robin Grieve used two 2016 papers: Parliamentary Commissioner for the Environment Dr Jan Wright's Climate change and Agriculture: Understanding the biological greenhouse gases; and Motu Economic and Public Policy Research's Cows, sheep and science: A scientific perspective on biological emissions from agriculture to support the PCRF claim.
However, when a similar opinion piece was published in the New Zealand Herald in August, the deputy director of the New Zealand Agricultural Greenhouse Gas Research Centre and a co-author of the Motu paper, Dr Andy Reisinger, strongly rebutted the PCRF claim and said in a letter to the Herald there was no scientific basis for Mr Grieve's assertion that somehow New Zealand's methane emissions were "mostly harmless".
Mr Grieve rejects Dr Reisinger's comments, saying the scientific basis for the assertion that New Zealand's emissions are mostly harmless is what led Motu to state in the report Dr Reisinger co-authored that emissions of CH4 and other short lived climate forcers do not have to decline to zero for the climate to stabilise; they only have to stop increasing.
