Quite a lot to report on with Dr Wilson Flood throwing a spanner in the works. He is a Doctor of Chemistry from the UK. I will report more on this later. A quick précis is that the premise that methane is a greenhouse gas 21 times more effective than CO2 is not right. Fonterra and Dairy NZ and MAF and all the other defenders of the crooked science of livestock emissions tell us that livestock convert CO2 to CH4 (methane) “a gas which is 21 times more effective than CO2 as a greenhouse gas.” (they say)
They are wrong; the gas is not 21 times more effective at all. Their confusion stems from the fact that it is 1 tonne of CH4 which is 21 times more effective than 1 tonne of CO2, but as Dr Flood points out there are a lot more CH4 molecules in a tonne than there are CO2 molecules in a tonne.
(This is because CO2 has a molecular weight of 44 while CH4 is only 16. There are 2.75 times more CH4 molecules in a tonne than there are CO 2 molecules in a tonne.)
If livestock take 1 tonne of CO2 and convert it to CH4 they will only produce 363kg of CH4
363kg CH4 is 21 times more effective as a GHG than 363kg CO2 (over 100 years) so;
363kg CH4 multiplied by 21 equals 7623 kg which would be the CO2 equivalent value of this methane. So while a tonne of methane might be 21 times more effective than a tonne of CO2 the gas itself when a molecule of CH4 is compared to a molecule of CO2 is only 7.6 times more effective than CO2 as a GHG.
The implications of this are huge, notwithstanding that livestock in a steady state converting CO2 to CH4 does not alter the concentration of either gas because it is part of a cycle and therefore does not cause global warming; all the calculations and all the arguments put forward by the Govt work on the basis that for every tonne of CO2 removed from the atmosphere and converted to methane, 21 tonnes of CO2equivalents are returned adding an extra 20 tonnes of these mythical CO2e’s to the mythical atmosphere.
But now it turns out for every tonne of CO2 removed only 7.6 of these mythical CO2equivalents are returned adding 6.6 tonnes of mythical CO2e. A long way short of 20, which throws everything they say and have calculated out the window.
The world seems to be crumbling a bit for the likes of Fonterra and the politicians who argue that methane needs mitigating. It needs to crumble a lot faster and I am working on the implications of this information to see what we can use to help this process.
Watch this space.
Also the Executive of Pastural Farming met on the 30th May to pass the annual accounts. You will receive these shortly and a review of things discussed. I have had a set back in that the website has had some issues, a number of newsletters have not gone out so it is being repaired and some new features put in. This is an expense we did not need but we now have a new look website, check it out.
A member sent me this, apparently there is confusion about livestock emissions which is causing lack of buy-in by the public and primary industries to the intentions of an emission trading scheme (ETS). I don’t know whether we are to blame for any of the confusion and lack of ‘buy in’ I certainly hope so.
I am not sure what the motivation of Massey University in putting this on, they talk about carbon which in scientific terms is an atom but by the way they talk about it maybe they are not talking about the scientific carbon but the political one. If anyone goes to this I would appreciate knowing how it went.
Carbon – the science and the sense
Tuesday, 28th June, Palmerston North
AgHort Lecture Block, Riddet Road, Turitea Campus, Massey University
A one-day Forum aimed at clarifying some issues regarding ‘carbon’, carbon cycling, stocks and flows, and carbon equivalence (for example in greenhouse gas, soil organic matter or trees) that have led to confusion and lack of buy-in by the public and primary industries to the intentions of an emission trading scheme (ETS).
The goal of the carbon day will be to build on the basis of better public understanding of the carbon cycle (and carbon equivalence) to identify how New Zealand can advocate a strategy to manage ‘carbon’, to assist in sectors’ decision-making around the effective management of carbon and all its implications to encourage NZ industry and public to ensure that resources
are used more efficiently.
Neil Henderson says
I first saw this paper by Dr. Flood some time ago. It is such basic science I am surprised it has not been put out in the public domain sooner. One can only wonder why it has not.
However MAF DOES know this basic science. When I discovered Flood’s paper I immediately did a check of MAF’s CO2 equivalents for livestock. They do take it into account. Here are their figures from a power point slide shown in the ‘Train the Trainer’ seminars last year. It gives an example of ‘Net Dairy Farm Emissions’.
In: 20 tonnes C as CO2
73.3 tonnes CO2 equivalent
Out: 19.84 tonnes C as CO2
0.16 tonnes C as CH4
77.23 tonnes CO2 equivalent.
This has the 7.6 conversion factor.
So this begs the question as to why we ALWAYS, including in the above seminar, hear that methane is 21 times more powerful than CO2 when it is not, in the context of livestock emissions, because livestock can only make a methane molecule by destroying a CO2 molecule.
The seminar quoted above was run by DairyNZ on behalf of MAF. I wrote to both MAF and DairyNZ about my concerns. Only MAF replied. They said they stand by the carbon cycle showing methane with a GWP of 21 and that stand by the way DairyNZ presents the carbon cycle.
I also took the issue up with Nick Smith. He however tried to challenge me on the need to make the conversion based on molecular weight. It would appear he is not as science literate as he would like to think he is.
The main conclusion I draw out of all this is that the only weapon the AGW brigade have is fear. If they went around saying methane was only 7.6 times more powerful, not enough people will get a big enough fright to be galvanised to action.
John Riddell says
A basic principle in “Climate Science” seems to be it doesn’t matter if the calculations are wrong, so long as you get the right answer.
When raising the subject of Global Warming Potential (GWP), make sure you ask what is the GWP of water vapour.
( http://www.geocraft.com/WVFossils/greenhouse_data.html ) They always leave it out as it makes even CO2 seem insignificant.
I was looking up information on GWP recently and found this statement “Over the past 20 years the government has transformed New Zealand from an agrarian economy dependent on concessionary British market access to a more industrialized, free market economy that can compete globally.” at a place called tradingeconomics.com ( http://www.tradingeconomics.com/new-zealand/methane-emissions-kt-of-co2-equivalent-wb-data.html )
I thought it was an interesting statement given that NZ still is very reliant on agriculture with a bit of help from tourism. I don’t feel we are much more industrialised than we were 20 years ago. A statement like this above a table on NZ methane emmissions seems to be trying to minimise the relative importance of agricultural contribution to the economy. They are in effect saying that NZ agriculture is no longer so important and therefore taxing it will not have as much negative effect.
Katherine Durand-Donaghue says
You idiots. A tonne of CH4 molecules is still 21 times more potent a greenhouse factor than a tonne of CO2, no matter how many molecules there are in each tonne! This is the answer to your question about why we always hear that methane is 21 times more powerful than CO2 – because it is measuresd in tonnes, not molecules! A tonne is a tonne is a tonne!!!
Also, cattle don’t destroy CO2 molecules to make CH4, they eat cellulose molecules in carbon based plants, which are C6H10O5, and release some of the carbon and hydrogen as CH4. The plants remove CO2 from the air to make the cellulose, in case you missed that.
And everyone knows that H2O is a more potent greenhouse gas than either of these – that is one reason we don’t have hydrogen cars pumping out more water vapour. Being amazed about it isn’t going to change it!! Goodness, guys, catch up!
Robin Grieve says
Not sure you understand the issue fully Katherine, the officilal explanation given to farmers by MAF is that the process of ruminant farming converts CO2 to CH4 and the CH4 is 21 times more potent as a greenhouse gas. So for every tonne of CO2 (which is one tonne CO2 equivalent removed from the atmosphere) 21 tonnes of CO2equivalent is returned as CH4. Therefore the CH4 emission is having the effect of returning a greenhouse gas 21 times nore potent than the one that was removed.
But MAF are wrong because the CH4 returned is not 21 times more potent than the gas removed because it is one molecule of CO2 that becomes one molecule of CH4. On a gas molecular basis, which is the one that is important here, CH4 is only 7.6 times more potent than CO2,
The relevant GWP of a tomne of each is irrelevant.
Yes the cow does not eat the CO2 but the farmer is the one who owns the land which grows the grass so the farm removes the CO2 from the atmosphere and must receive credit for it.
It is quite complicated and thanks for reading it, I hope it is clearer to you now.
Katherine Durand-Donaghue says
Cattle do not convert CO2 to CH4.
Katherine Durand-Donaghue says
I quote: “The function of the rumen as a fermentation vat and the presence of certain bacteria promote the development of gases. These gases are found in the upper part of the rumen with CO2 and CH4 making up the largest portion, Table 1. The proportion of these gases is dependent on rumen ecology and fermentation balance. Typically, the proportion of carbon dioxide is two to three times that of CH4, although a large quantity
of CO2 is reduced to CH4.”
This last phrase is being misunderstood: ALL of the CO2 and CH4 gases in the rumen come from the grass (cellulose, C6H10O5). The conversion of a portion of this CO2 – originating from the cellulose – to CH4 in the rumen does not mean that cattle are converting CO2 from the air into methane: it is part of a chain of reactions from plant carbon (cellulose) to CO2 to methane before it is released, but all originates from the grass, not the air.
In essence cattle convert plant carbon into CO2 and CH4, and the proportions vary.
Katherine Durand-Donaghue says
Should have written “Cattle do not convert CO2 from the air into CH4” in the 2:20pm post, sorry.
Robin Grieve says
You are quite right in the science Katherine but you have to remeber it is the farm that we are dealing with not the animal. If the C in the grass was once an atom of C in a CO2 molecule then the process of ruminant farming has resulted in a molecule of CO2 becoming a molecule of CH4 which ultimately becomes a molecule of CO2 again. Of course we have other molecules involved in this process but I am just following the C atom.
MAF and Govt’s failure is they say CO2 becomes CH4 and leave it at that and ping farmers for the difference in GWP (global warming potential) of each. MAF and Govt should look at the whole cycle by where the CH4 becomes CO2 again.
By just looking at one part of a cycle one didstorts the truth, it is like watching people walikng in and out opf a room but only counting those that walk in, ignoring those which walk out. At the end of the day then declaring that the room is full when in fact it is empty.
That is the rubbish you get when you only look at part of a cycle. I suggest starting with the C in the grass as you are doing and finishing with the production of CH4 is even more limiting than MAF’s position. And if it is posible even more wrong.
Lindsay Brown says
I would like to congratulate Robim Grieve on his persistance with this issue.It is the sheer stupidity and waste of resources involved that keeps me writing on the subject of taxing livestock emissions.I have recently been to the U.K.where they use fossil fuels even for home heating which makes taxing our cows seem even more rediculous.What really riles me is the attitude of the scientific community. Robins assertions on enteric methane emissions are absolutely scientifically correct yet not one scientist has said so.I have qualifications myself but this issue is actually simple enough for a third form pupil to grasp. I challenge anyone employed in this field to show us in a clear and concise argument that enteric methane should be treated in exactly the same way as fossil fuel emissions in spite of the fact that the caron atoms in the methane end up back where they began in atmospheric CO2.The methane concentration in the atmosphere is unchanged by our activities unless we increase or decrease our livestock numbers.The present position of government is perpetuating a myth and wasting precious research resources and could lead to a reduction in both food production and viability of our major export industries.
Meyer says
OK, what about this then?
http://www.global-warming-forecasts.com/methane-carbon-dioxide.php
Meyer