New Zealand shows climate gains, but urgent action needed
The Climate Change Commission’s 2025 emissions reduction monitoring report reveals steady progress on the reduction of New Zealand’s climate pollution.
But science is never settled as commonly claimed.
For example, the three estimates of the warming effect of methane are:
The Greenhouse Effect is 75% water vapour, 25% CO2 and trivial effects for methane and nitrous oxide. Methane is 7-8 times more effective re warming than CO2 = 1. The IPCC in its 2021 report states “expressing methane emissions as CO2 equivalent of 28, overstates the effect on global surface temperature by a factor of 3-4”.
This error is corrected by using Global Warming Potential (GWP) of 7-8x more effective than CO2. This is the basis for the GWP* metric, which is being considered by industry.
The cost of ignoring this IPCC conclusion to NZ is about $2 billion/ annum, which is apparently of no interest to bureaucrats and politicians.
Farming leaders (as well as the politicians, bureaucrats and government paid scientists) have no interest in even discussing the research behind the new US conclusions (zero or trivial effect of methane as a GHG). This is in spite of the fact that:
- This is the actual situation, the most complete "validated model" science,
- There would be or should be no cost to farmers, or the country for methane emissions,
- The zero-effect assessed for methane would reduce NZ's total emissions by 30+%; huge cost savings for NZ, and the rest of the world.
The contention that climate policy is “science based” is simply not true.
With about $200 million already spent on R & D with little to show for it, the chances a further $350 million for new research will produce solutions don’t appear too hopeful.
The new metric GWP* is based on very dubious science, but it is not suitable for “on farm” measurement of methane required under HWEN. It could be used for an industry-based approach, which would not require individual on-farm measurement. I would get rid of the immense and expensive bureaucracy and consulting overview required, a huge burden for industry.
Much is made of the split gas approach now enshrined in legislation, which treats methane separately from CO2. With no effect for methane, this is logical.
CO2 is touted as a long-lived gas, much of which is hyped to stay in the atmosphere for centuries to thousands of years. It is not a long-lived gas at all.
The half-life of CO2 is 10 years only. Just how we got to industry commentators saying human CO2 virtually stays in the atmosphere for ever is anyone’s guess.
As John Maynard Keynes said: “If the facts change, I change my mind, what do you do sir”?
Wouldn’t it be a good idea if all the parties could talk to each other for the industry and NZ’s benefit?
Dr Jock Allison. ONZM, FNZIPIM is a former head of AgResearch Invermay.
