Real science puts agricultural methane in its proper place as a contributor to greenhouse gas emmissions, a 'flow' pollutant and less concerning than 'stock' pollutants like carbon dioxide

Farmers have been quietly nervous about the Governments aspirations of zero net Greenhouse Gas (GHG) emissions by 2050. With agriculture's GHG emissions making up approximately 48% of the total nations emissions, most farmers recognised that they would be dragged into the program at some time.

So, it should have come with considerable relief to hear the report expressed by Professor David Frame from Victoria University. In research he has been involved in along with Oxford and Reading Universities and Norway’s Centre for International Climatic and Environmental Research, he stated there was clear evidence in the way methane, which makes up the bulk of agricultures emissions, needs to be reviewed.

Methane makes up around 42% (under current measuring) of New Zealand’s GHG emissions and for livestock farmers has been the more difficult of the gases to reduce.

The new research promotes the view that methane in the New Zealand livestock context is a “flow” pollutant, i.e. as fast as it goes into the atmosphere a similar amount is coming out, and so has not been responsible for the build up GHG stocks in the atmosphere since 1990, which is the time frame legislation is concerned with.

CO2, for example, is a stock pollutant and over 40% of CO2 emissions remain in the atmosphere for 1,000 years. Methane has a half life (reducing to 50% ) of about 10 years.

Not all interest groups are going to welcome this news, but for a change some of the heat should be coming off farming at least in the environmental context.

Andrew Hoggard of Federated farmers welcomed the news and said it was gratifying to see distinctions made between intensive but short lived greenhouse gases, like methane, and weaker, but persistent, gases like carbon dioxide. "There is this better understanding of the fact that a short-lived gas has a different impact from a long-lived gas and you have to treat them differently."

A Greenpeace spokesperson saw it as a “cope out” by Government.

Farmers still have to deal with nitrous oxide which makes up about 30% of livestock emissions, but as this requires going through the soil before volitsation occurs there is more opportunity to act upon and reduce its impact. Dicyandiamide (DCD) also known as EcoN, a product primarily developed to enhance the effectiveness of nitrogen applied to pasture also had the ability to reduce nitrate leaching and also the volitsation of nitrogen into nitrous oxide (N2O). Reductions ranging from 18% to 74% have been recorded. Unfortunately DCD’s were withdrawn from use in 2013 when traces of DCD was found in New Zealand milk and don’t appear to be able to be used anytime soon. However, DCD’s have alerted scientists and others to the possibilities of some form of intervention.

Some lifts in the lamb schedules this week closing the gap between advertised schedule returns and what saleyards are paying. A small lift, again, in saleyards with top lambs exceeding $200 in several South Island sales and with lighter lambs being pulled up also. The North Island seems to be losing some of the heat of previous weeks.

The Christchurch wool sale last week was close to the previous Christchurch sale, however the better lambs wool that remains experienced a small lift in prices.

Given the upward trend of the US dollar and increase cow kill from the MPB cull it was a pleasant surprise to see some processors lifting the price for cow. No movement on the prime front with local demand dropping off.

No change to the venison schedule. However, minimum price schedules are now out from one company. It will be interesting to see how these compare to the advertised schedule.

We welcome your help to improve our coverage of this issue. Any examples or experiences to relate? Any links to other news, data or research to shed more light on this? Any insight or views on what might happen next or what should happen next? Any errors to correct?

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Time for real "real science." The methane that breaks down yields CO2 and water vapor. It's a double wammy, not the "short lived" earth heater (actually a triple whammy considering ozone depletion). Even worse, the breakdown water vapor is a potent greenhouse gas, so a quadruple whammy. From wikipedia (
The most effective sink of atmospheric methane is the hydroxyl radical in the troposphere, or the lowest portion of Earth’s atmosphere. As methane rises into the air, it reacts with the hydroxyl radical to create water vapor and carbon dioxide. The lifespan of methane in the atmosphere was estimated at 9.6 years as of 2001; however, increasing emissions of methane over time reduce the concentration of the hydroxyl radical in the atmosphere.[38] With less OH˚ to react with, the lifespan of methane could also increase, resulting in greater concentrations of atmospheric methane.[68]

If it is not destroyed in the troposphere, methane will last approximately 120 years before it is eventually destroyed in Earth’s next atmospheric layer: the stratosphere. Destruction in the stratosphere occurs the same way that it does in the troposphere: methane is oxidized to produce carbon dioxide and water vapor. Based on balloon-borne measurements since 1978, the abundance of stratospheric methane has increased by 13.4%±3.6% between 1978 and 2003.[69]

Reaction with free chlorine
Methane also reacts with natural chlorine gas in the atmosphere to produce chloromethane and hydrochloric acid (HCl). This process is known as free radical halogenations.[70]

CH4 + Cl2 → CH3Cl + HCl
The HCl produced in this reaction leads to catalytic ozone destruction in the stratosphere.[69]

"How much does water vapor amplify CO2 warming? Studies show that water vapor feedback roughly doubles the amount of warming caused by CO2. So if there is a 1°C change caused by CO2, the water vapor will cause the temperature to go up another 1°C. When other feedback loops are included, the total warming from a potential 1°C change caused by CO2 is, in reality, as much as 3°C."

You know bender, I take a lot more notice of what David Frame (director, NZ climate change institute) says, than someone randomly cut and pasting from Wikipedia.

Even if the NONrandom source is correct?

Methane is also destroyed by lightening - burns very well. Not taken into account with removal calculations.

We are talking I think ~ 1700 - 2000 parts per billion - Very hard to think it will have any effect on anything at these levels. Makes up ~ 0.000,001,700 of the atmosphere.

As a basis for scale - walk 1 kilometre ( 1,000,000 mm ) then walk an additional 0.3 mm and see if you feel this increment is significant. The difference between original methane and current levels.

Simple fact is that the temperature of ANY body orbiting the sun - that's us - removing any internal radioactive decay or internal work done - is determined solely by the temperature of the sun, the distance from the sun and the albedo of the body or the amount of energy reflected.

Nothing else as in nothing else - determines the average temperate on earth - basic black body physics.

Sun spots and Galactic Cosmic Rays have the ability to modify the albedo by generating cloud and aerosol formations, which can also alter Earth's temperature.

The make up of the atmosphere has no impact whatsoever on temperature. CO2 is transparent to sunlight so cannot affect albedo. Sulfur dioxide is not so can and does affect temperture - eg Mt Pinatubo.

Gas laws - Boyle etc - dictate that the temperature at any level in the atmosphere is simply proportional to the force of gravity and the mass of gas above which determines the pressure - hence the temperature(s) taking into account initial conditions eg tropics vs Poles.

If you look at a satellite image of those areas showing the greatest warming - they coincide with the areas of greatest pollution as there is no debate that carbon black alters the albedo of the earth.

Now listed equal in impact by the IPPC science report to the policy advisers as having equal impact as agriculture.

The obvious additional warming in the Northern Hemisphere vs Southern an be entirely accounted for by pollution. Primarily coal fired power stations, cement works and industrial and transport processes.

Anthropogenic Yes - CO2 No.

Latest Satellite data shows average current global temp ( Spencer data ) is no different from the average of the last 20 years yet CO2 levels have risen right through that period.

Available at:

When we get a significant cooling period - as we eventually will - we will then maybe get some common sense into this debate.

I refer to Doris' comment above. Why should we take your ten minutes of Googling more seriously than the conclusions of Professor David Frame from Victoria University from research he has been involved in along with Oxford and Reading Universities and Norway’s Centre for International Climatic and Environmental Research?

The data JB quotes shows global temperature anomalies are back where they were in 1983 despite a 30%+ rise in atmospheric CO2 since 2000. Researching agricultural methane is irrelevant if inter glacial warming continues at a rate slower than pre-1940 when industrial CO2 emissions were a fraction of what they are now.

If you want to go down the appeal to authority track have a read up the Roy Spencer bio, that JB quotes, and compare it to David Frame.

Thus one would expect Arctic Ice to be expanding yet it is retreating so drastically that the ocean may be ice free in summer within a decade or so. That is why there is a considerable increase in the building of ice breakers as new routes are opened up between the Americas, Asia and Europe etc.

Not reducing drastically. Data is so boring compared to predicting the future and scaring the children.

Arctic Ice volume is on the '04-13 average.

Greenland SMB is well above the '81-10 mean.

Bender, if you refer to David Frames report and RNZ discussion he would agree with you that methane does revert back to CO2 but that same CO2 is then absorb by a plant eaten by and animal and then re-emitted as CH4 hence a flow rather than a "stock" pollutant. Methane produced from fossil fuel sources are a (the) problem and are more of a "stock" rather than a "flow"  as they are a 'new' source rather than a 'flow' source. And re "science" it does change and move forward. In this case in favour of livestock farmers. Good conversation though (and I should add I'm not an expert by any means).


CO2 and methane can't necessarily be regarded as "stock" "pollutants" unless soil organic carbon is taken into account. Which the climate change industry in NZ ignores and prefers to quote only gross emissions from agriculture not net. David Frame, typically, appears to ignore SOC in this piece.

"Generally, because of their large enteric CH4 emissions, grazing systems have been pointed to as the greatest area for attention for decreasing the GHG footprint of beef production. However, measurements of SOC have not typically been factored into these outcomes. In fact, if soil C is sequestered through best management practices, our results suggest that enteric CH4 from the finishing phase can be substantially mitigated. We demonstrated this based on measurements of soil C and cattle productivity at the Lake City AgBioResearch Center from 2012 to 2016, which indicates a sink during the finishing phase of −6.65 kg CO2-e kg CW−1 which is similar to the results of Beauchemin et al. (2011). "

I've spent a bit of time looking at this latest bit of research, and although I'm no climate scientist I do have a science background so I think I've got my head around it.

The key difference between stock and flow pollutants is the speed of decay (not the source). Because methane decays rapidly and has a short cycle, if the rate of emission of methane is stable, as one molecule is emitted another one simultaneously decays. So if you were emitting 100 methane molecules per day, after a few years the number would stabilise and you would end up with a stable number of methane molecules in the atmosphere.

For stock pollutants like carbon the situation is different. Because they hang around for so long, every extra carbon molecule emitted does further damage - the effect is cumulative.

So with methane - reducing the amount emitted would have a one-off beneficial effect. Increasing the amount emitted would cause more global warming. Emitting a constant amount is neutral for global warming.

Bender's thrown a boomerang here. Frame's research doesn't fit his/hers worldview so it must be hokum. Galileo, anyone?

Attacking the messenger, not the message.