The Government has taken livestock emissions out of the ETS review for later this year. The ETS is an absolute joke so there will be plenty to review including the dodgy forestry credits NZ foresters sell, without the contentious issue of livestock emissions; but there does appear to be a changing in the language around enteric methane in particular.
Dr Adrian Macey from Victoria who is NZ’s first Climate Change ambassador and Professor Dave Frame, also from Victoria University, have come out against the current treatment of enteric methane.
We have been saying for years that the impact of enteric methane on global warming is overstated and now we are seeing a change in attitude developing among scientists.
It is not time to pop the champagne, where we agree is that the impact of enteric methane is overstated, we argue the impact of enteric methane is overstated because it is zero, Frame and Macey argue that it is overstated because the wrong metric to quantify it is used.
Our argument is that because the definition of an anthropogenic activity (one that causes global warming), as defined by the UNFCC, is an activity which alters the composition of the atmosphere, enteric methane emissions could only be regarded as an anthropogenic activity if it causes an increase in the atmospheric concentration of methane. It doesn’t, its effect is zero.
Frame argues two things. Firstly he argues that while it was previously thought that reducing methane emissions would help buy time in the fight against CO2, Frame now says that “action on these other pollutants (eg methane) does not ‘buy time’ to delay action on carbon dioxide. When commenting on a report of research from Victoria and Oxford Universities released in 2013 he said;
“The reality is that today’s methane emissions matter little for peak warming unless carbon dioxide emissions drop rapidly in the coming decades. As long as carbon dioxide emissions are not falling, methane emissions can have little impact on the overall magnitude of warming.”
This is good news because it means that if your goal is to reduce peak warming then you should not be wasting your time trying to reduce livestock emissions of methane. The UN agrees and does not want countries diverting energy and resources in to reducing emissions of methane because it will invariably be diverted away from action on CO2 which is the only problem, according to them. Our Government understands this so why do they continue to waste tens of millions of dollars on futile research on livestock rumens?
Macey and Frame also argue that as well as methane not being the problem, the GWP (global warming potential) metric they use to quantify these methane emissions in terms of ‘carbon’ is the wrong metric and overstates the methane by a factor of seven.
Firstly let me say there is no right metric. The politicians ask the scientists to come up with a metric that can be used to quantify lots of different gases. This is like trying to come up with a description that suits both chalk and cheese in every situation. It can’t be done but our scientists prostitute themselves to the politicians who pay them and so produce these metrics which are never accurate in all situations. Better to stay true to your science and tell the politicians it can’t be done, but that is not how climate scientists work.
GWP is the metric we use now in our national inventory and what it does is it compare the radiative forcing effect of each gas over a certain time horizon. The GWP of methane is 28 which quantifies 1 tonne of methane as 28 tonnes of CO2 equivalent or ‘carbon’
GTP (global temperature potential) contrasts the temperature effects of a pulse emission of one kg of a greenhouse gas relative to CO2. The GTP of methane is 4 which puts 1 tonne of methane at only 4 tonne of CO2 equivalent and significantly changes everything. Our emissions of carbon would dramatically reduce at the stroke of a pen should we use this metric.
The reason Frame and Macey say that GTP is the right metric is because now that the world has a temperature target and its policies are focused on it, the metric chosen should reflect that focus. It is the global temperature potential of a gas that is important now, and not the global warming potential.
Frame also went so far in a recent interview as to say there is scientific merit in not including methane in our national inventory at all.
So we are making progress. Macey is a doctor of French and Frame physics, so neither are climate scientists but they have the ear of the media who treat them as climate scientists, and they are raising questions over the current treatment of enteric methane, just as we have been for years now. So we welcome them to our side of the debate on this and all power to them.