OPINION: Farmers are being herded into a very dangerous crush.
The other reason proponents, such as the Climate Change Commission, argue that we have to take actions is that methane is NZ’s big problem – because our livestock numbers are high relative to other GHG-producing activities – so we need to pull our weight and “do something”.
Answer: We are already doing something.
Our farmers are way ahead of the play. They are already offsetting all the methane they produce by sequestering huge amounts of CO₂. Their grass, soil and other farm vegetation absorbs as much GHG as their cows and sheep produce. All vegetation takes in CO₂ for photosynthesis.
This balanced situation using the age-old natural carbon cycle separates farming from other GHG emitters who have no natural offset. That is why farming should never be in the ETS or face any restrictions.
But wait there is more.
Of the one degree Celsius of warming we have recorded over the last 150 years, methane is allegedly responsible for a mere 10% -20% of this increase. Some 40%, at least, of methane emissions are natural. So, the effect of 10% reduction proposed by the Climate Change Commission makes no sense at all. It is pitiful.
Hang about – it gets even worse still. And it is going to get all complicated and ‘sciencey’.
GHGs operate in the electromagnetic spectrum. Figure 1 (shows the radiation transmitted by the atmosphere as UV, visible light and Infrared radiation (see the yellow band in the figure). The left-hand side of the figure (left of the red dotted line) shows the region of incoming solar radiation (0.2 to 3 micrometres wavelength span). The right-hand side denotes the re-radiation from earth as long-wavelength infrared energy covering the 3 to 70 micrometre span.
Each greenhouse gas is analysed separately in the lower part of the graph. The width and height of each absorption peak for each gas is clearly shown. The height of the peak denotes the maximum amount of radiant energy that each gas can possibly absorb over that range of wavelengths. The width of each absorption band shows the precise wavelengths to which that the particular greenhouse gas responds.
It you examine each gas, you will see that methane, nitrous oxide, and ozone, only have a few narrow absorption bands with none absorbing 100% of any wavelength. Even CO₂ has only four peaks where absorption is over 50% and these occur in narrow bands, meaning CO₂ absorbs little energy.
Water vapour, in stark contrast, absorbs over a far wider range of wavelengths with three broad peaks of maximum 100% absorption and multiple small peaks. Above about 18 micrometres water vapour absorbs 100% of outgoing infrared energy.
The published evidence shows that by far the dominant GHG absorbing solar radiation is water vapour. The absorption potential of solar radiation by the other GHGs is minuscule or absent.
From a farmer’s point of view, methane and nitrous oxide can clearly be ignored as having no appreciable effect on warming.
At a total only 0.012% of all the GHGs, or 0.00018% of the total atmosphere methane (and nitrous oxide) is physically incapable of impacting temperature.
And we are going to beat our chests over a 0.13% reduction per year of something already unbelievably trivial and inconsequential.
Time for a brain check, surely!
Even decimating our entire cow herd and all our sheep will not make any impact on temperature at all – so infinitesimal it could never be measured by the most effective measuring tool.
Meanwhile, the Climate Change Commission and the Government put their collective heads in the sand over Article 2 of the Paris Accord. Pretending we can cut the national herd by 15% plus other constraints, and not have a disastrous reduction in production and exports simply shows alarming ignorance.
One can only further conclude that something else is going on that isn’t science – virtue signalling by NZ leaders and dubious politics at international level.