Friday, 19 October 2012

The New Zealand Farming Story: Tackling Agricultural Emissions

Today we are very excited to release our new short film on New Zealand’s agricultural emissions. Although the topic may sound dry (though hopefully not too dry if you visit this blog!) our filmmaker Jess Feast has done an excellent job of making an engaging film on an extremely important topic for the future of our country, our planet, our people and our stomachs. (She also made our films about improving the water quality in Lake Rotorua).

The film covers a wide range of topics, and many of the ideas in it come directly from what we learnt through the AgDialogue process. Importantly, we cover how we might be able to achieve some real reductions in New Zealand’s agricultural GHGs (greenhouse gases). You will get to meet some of the participants and experts from AgDialogue, including two of our star farmers, Mike and Megan.

The film speaks for itself, so you are better off watching it than reading about it. But before you do that, I’d just like to acknowledge all the hard work that went into making the film. To all those in the AgDialogue who gave their time and those who have done related research in the past few years, this film is dedicated to you and the hard work you have done.  Also thank you to our filmmaker Jess and the Ministry for Primary Industries for its support. The work will pay off in creating a more sustainable and prosperous future for us and future generations.

Oh, and if you like the film, please share it far and wide. New Zealand is uniquely placed to be able to make a big difference to levels of agricultural GHGs (greenhouse gases) around the world. And everyone in this country can make a difference.

UPDATE: Teaching materials to accompany the film have now also been released. These can be found here.


  1. As a sheep and beef farmer I am very, very disappointed.

    Fact one. Livestock emissions can only cause global warming as a result of an increase in numbers. A constant number of animals at a constant level of production maintain the atmospheric concentration of methane at a constant level. By the definition of the UNFCCC global warming can only occur through an increase in green house gases. The calculation that has some 30 to 35 % of NZ's emissions being from livestock methane takes our gross emissions, not the increased emissions from an increase in livestock numbers. Our emissions profile is therefore fatally flawed.

    Fact two. The calculation used to obtain our emissions level is only one of several potential methods. It works on a base of 100 years to compare the effect of methane to carbon dioxide. At present this ranks methane as 21 times more powerful than carbon dioxide but from January 1 2013 it will rise to 25, lifting our emissions profile significantly at the stroke of a pen. This number of 25 is not precise. It is merely the midpoint in a very uncertain calculation where the range extends from 19 to 31.
    Tim Flannery, an Australian climate scientist, has claimed that carbon dioxide will last a thousand years in the atmosphere. If we compare methane on this basis the relative warming of methane drops to about 7.
    A totally different method of comparison rates methane in a range of 4 to 14 on a timescale of 100 years.
    Therefore to state NZ's methane emissions are ‘X tonnes’ is farcical because it is entirely dependent on the very arbitrary method chosen to calculate it. Just because Kyoto stipulates the particular method in current use does not make it right.

    Fact three. If we use the current method of calculating methane emissions and make the assumption that a doubling of carbon dioxide levels will raise the temperature 2 degrees, it is a very simple process to calculate that doubling the amount of methane produced by all the farmed livestock in the world would only raise the global temperature by 0.01 degrees. Yes that decimal point is in the right place. Does anyone seriously think any farmer is going to be interested in adding any cost to his operation for his share of an unmeasurable temperature difference?

    Conclusion. The first step that needs to desperately take place in the whole global warming issue in general and the livestock emissions issue in particular is to actually quantify the size (or lack of size) of the problem.

  2. Hi Neil

    Good to hear from you, thanks for the comment.

    Regarding your first point: I think that it is correct insofar as a drunk is correct to say that the only problem is if he continues to get more drunk. Natural decay processes remove CH4 (methane) from the atmosphere, so if you emit the gas at a constant rate then eventually the decay processes will reach an equilibrium with the emissions (over a period of about 50 years). This means the concentration of CH4 no longer changes, and temperature rises by a finite amount (although you'll still have longer term sea level rise, melting polar ice, instability introduced to permafrost areas and so on). At present we have about 0.8 degree warming compared to preindustrial conditions, of which around a quarter is due to increased CH4 levels (the rest due to CO2 and other gases). Even if total CH4 emissions remained constant (which they haven't - they've risen) it would still be the case that if we reduce CH4 emissions, we reduce the contribution of CH4 to warming. Given that we want to reduce the overall warming effect of all gases, that would still be a good thing.

    Regarding your second point: You're correct that the relative importance of different gases varies over time. However, just because we can consider different time frames doesn't mean that any measurement is "arbitrary" or meaningless, or that we can choose whichever time frame we like to try downplay the importance of whichever gas we are talking about. A good way forward might be to try work out the time horizon(s) that matters most for climate change impacts and then use that to guide one's assessment of the relative importance of different gases. I've blogged further on this here:

    Regarding your third point: Firstly, can you show me the calculations that led to this figure? Secondly, the reasoning is overly simplistic because climate change is a collective problem. Even if the contribution of methane from livestock is in the ballpark you suggest, this doesn't mean we shouldn't address it. To do so would suggest that everyone is permitted to slice the emissions pie however they like so that any industry, country or individual looks too insignificant to make a difference. And if we are concerned about climate change, as the science suggests we ought to be, this is an unsatisfactory approach to take.

  3. I admire the courage of some Newzealanders who dare to state that destocking of cattle is one solution. I can fully agree with that thought as it fits in my thinking: Eat Less Meat - It Is Good For The Individual And Good For The Environament.

    Further I would like to propose to the Newzealanders to make use of large biodigesters to capture methane gas and use it for cooking, heating and electrical energy generation.Perhaps lagoon type digesters will be a good option. Yoe will also end up with good detoxified organic fertilizer and and avoid leaching toxins into your water sources.
    Biodigesters could then also be used for your slaughterhouses to responsibly cope with the potentially dangerous residues.


Comments will be moderated by the author of the post. Bad language or personal attacks will not be published.