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Agreed, let’s follow the science . . .


Our columnist today is right to note that there are opportunities to reduce greenhouse gas emissions from cows and sheep, some of which are obstructed by New Zealand's 2003 genetic engineering laws. However, he rather ruins his case by first ascribing the term “speculative theory” to issues around livestock emissions. He is also dangerously wrong to suggest climate action should be deprioritised due to Covid-19 and the need to rebuild our economy.

The greatest threat to existing life on Earth and to humanity's future economic wellbeing remains the risk that we do not collectively and rapidly reduce anthropogenic greenhouse gas emissions.

The science that shows our agriculture industry causes just under 50 percent of the warming attributable to New Zealand emissions (if de-forestation is excluded) is solid; the best information on this comes from the work of Andy Reisinger and Sinead Leahy and can be found here.

It also shows that the 100-year GWP (global warming potential) metric used to compare the climate impacts of different greenhouse gases does a decent job in estimating past and future warming; where this metric falls down, and is the subject of vigorous scientific debate, is under ambitious mitigation scenarios where it can give misleading results with respect to the treatment of methane and carbon dioxide. (That is why it is best to use individual gases when estimating contribution to warming.)

In addition to this science discussion, there is an even more complicated discussion around the link between metrics and emissions reduction targets. It is possible that the outcome of this could in future see New Zealand's target range of a 24 to 47 percent reduction in biogenic methane emissions by 2050 revised downwards.

Regarding opportunities to lower emissions on farms, a year ago the Government's Interim Climate Change Committee raised prohibitive regulations around genetics as a potential obstruction; noting a GM ryegrass developed by AgResearch that could reduce both methane and nitrous oxide emissions from grazing animals, but was having to be tested in the US. In August last year our top scientific body, the Royal Society Te Aparangi, joined calls for an overhaul of our genetic engineering laws after finding an “urgent need” to consider how we might use this contentious and evolving technology in the areas of pest control, primary industries and medicine.

• See also August 12, 2019 editorial here.

  1. Clive Bibby says:

    Let’s look at some facts.
    The greenhouse gas emissions identified as by-products of individual nation’s economic development histories are, as yet, unproven causes of any global warming process*. Until they are, they remain, in that context – just part of speculative theories (my words).
    The editor’s rush to use hyperbolic language to describe my description of modern governments’ reactions to these facts is pathetic.
    Why is it dangerous to simply acknowledge the dilemma faced by many of the signatories to the Paris Accord who have been forced to re-prioritise the components of their individual economic development strategies to include a greater use of fossil fuels (coal-fired energy plants) and continued use of animals in the food chain? They have no choice!
    Hardly “dangerous!” – more like “responsible!”

    * Footnote from Ed: For someone who has campaigned for a local political response to climate change, it is fascinating that you clearly have little idea about the science of climate change or are somehow in denial of the fact that human activity is warming the planet dangerously. This is a false, denialist statement that would not normally be published in The Gisborne Herald.

  2. Craig Bauld says:

    Dear Ed, thank you for the reference. I read it carefully and learned two things. First, that methane is not the problem, carbon dioxide is the problem. This is very strange because you have spent some time previously lecturing me that methane is the problem.
    Secondly, that you are hooked into a narrative promulgated not by scientists but by something called “emissions experts”. No scientist would dream of counting emissions without wondering about the source of those emissions.
    So indeed, let us follow the science. Science says that matter can neither be created nor destroyed. Science says that for every action there is an equal and opposite reaction. Science says cows do not create carbon, they ingest carbon and re-release most of it to the atmosphere. Not all, some builds beef, that doesn’t get released until we eat it. And where do cows find carbon to ingest? Well, duh, from the grass that farmers grow for them. And where does the grass get the carbon? Well, duh, from the atmosphere through the magic of photosynthesis.
    Studying outputs without considering inputs is kind of like studying mc squared. Doesn’t make a lot of sense without the other half of the equation.

    Footnote from Ed: Carbon neutral is not the same as greenhouse gas neutral. Some of the carbon taken out of the atmosphere by photosynthesis is returned to the atmosphere as CH4, which has very different properties to carbon dioxide with respect to absorbing infra-red radiation. Ruminant animals also produce N2O which is an even more powerful greenhouse gas.
    I haven’t lectured you Craig, I have just been responding to your mistaken views around livestock emissions. Please do read further on the topic.

  3. Clive Bibby says:

    I don’t give a rat’s arse whether you want to call me a denialist or a perpetrator of falsehoods (liar). I didn’t say that human activity wasn’t partially responsible for global warming. I just think it is far less of the ogre in the process that you are portraying – maybe inconsequential compared to other possible contributors such as solar flares etc. I certainly admit to being skeptical about much of this so-called science. But I am in good company on that score with eminent scholars who are far more qualified than either you or me to make an objective call on the results of the credible investigations so far.
    Want me to name a few.
    I thought not.