Farm methane is not as harmful.

Henley standard 2/12/21

Was COP26 a cop out or did it actually achieve anything meaningful? You have to wonder if it did, when the conference was closed by a tearful chairman after the shenanigans over the wording for a reduction in coal use. It also now appears, according to a report by Brazil’s space agency, that the decimation of their rainforest has increased by 22% in the last year. So any progress made at the conference regarding deforestation needs to cover that increase before there is a positive contribution from the latest proposal. Here in the UK at the last budget the chancellor decided to cut taxes on domestic air flights whilst George Eustice, Secretary of State for Environment, Food and Rural Affairs hinted that there might be a carbon tax on meat. You have got to question some of this and ask why is farming carrying the can for the problem with rising greenhouse gases (GHG) particularly when agriculture, as an industry, is only responsible for 10% in the UK whilst transport produces 27%? The farming debate mostly hinges on the methane gas produced by livestock which accounts for half of farming’s emissions. The rest are fossil fuels to power the machinery, deliver the produce and in the manufacture and use of synthetic nitrogen fertiliser.

Let’s look at methane, which although is in much smaller quantities in the atmosphere at 16% as opposed to 76% for carbon dioxide (C02), can trap roughly 28 times more heat than CO2. There are various sources of methane both natural and man-made. Natural include wetlands and large areas of water and of course plant eating animals such as cows and sheep. Burning fossil fuels also releases methane. On a global scale, agriculture produces 40% of the methane with the other 60% split equally between natural and human sources. Methane remains in the atmosphere for far less time than carbon dioxide, about a decade as opposed to hundreds of years for CO2. In addition, the methane from natural sources, including cattle, is different to that from burning fossil fuels because it is recycled. Starting off as CO2 in the atmosphere, it is taken up by plants which in turn are eaten by the animals. A by-product of their digestion is methane when they belch, pass wind and defecate. This then goes back up into the atmosphere and after about 12 years has all been converted back into carbon dioxide. That carbon is the same carbon that was in the air prior to being utilised by the plants. This is called the Biogenic Carbon Cycle. I can hear you saying ‘but surely the same happens with methane from burning fossil fuels?‘  Yes, but this originates in the earth as coal, oil or natural gas where it has been locked up for millions of years and so it is a net gain rather than recycling. This is all new and the calculation for greenhouse gas emissions is not as yet taking this difference into account. Hence livestock production is unfairly compared to methane from fossil fuels.

We still need to reduce the amount of methane produced by agriculture but it is clear that not all methane is equal and giving up on livestock derived food is not the answer, particularly if it means relying on more imported food or manufactured products trying to mimic meat and dairy. They all have a carbon footprint. Current research in livestock farming is looking at feed additives and diets to reduce the amount of methane produced in the first place. Genetics, in terms of breeding animals with more efficient food conversion rates, would also help as will different ways of dealing with manure to ensure less methane escapes when we handle it and use it on the fields as a natural fertiliser.

There is a raft of different agendas which are further contributing to all of this. Food manufacturers and supermarkets see the whole vegan/vegetarian movement as a way of up selling the food we buy. After all, milk or meat is what it is, however a manufactured alternative to milk has more than one ingredient in it and currently is more expensive than actual milk. In some cases it has a higher carbon footprint if you take into account the food miles, processing and marketing and calculate the methane produced in the way described above. We need to move to a system that fairly allocates a true carbon footprint to all the food we buy and especially all food that is imported.

2 thoughts on “Farm methane is not as harmful.

  1. Hi Simon, I really enjoy your farming column. It is interesting and informative. However, I must take issue with your argument this week that methane arising from farming is less harmful than methane arising from fossil fuels. It have exactly the same impact in the atmosphere – where it comes from doesn’t make any difference. I understand your arguments about a short term carbon cycle versus a long term carbon cycle, but the point is that the rate of methane emitted from even the short term cycle is greater than the rate at which it is being recycled, so it is still contributing to climate change. It is also more efficient to eat plants rather than feeding plants to livestock then eating them, so it does make sense to reduce the amount of meat we eat (I am not a vegetarian). However, I do agree that what we feed our animals and where that food comes from is extremely important. Good quality grass fed cattle in the UK are considerably more environmentally friendly than the feedlot ranches in other countries, especially if forests are cleared for that land. That’s why I always buy British.
    Keep up the good work.

  2. Hi Sarah. Thank you for your comments. I agree that methane could still be building. My main point was to try and draw the distinction between that produced by burning fossil fuels and the cycle of grass fed cattle. I believe we need to look more closely at this rather than political decisions made to protect the fossil fuel industry. It’s always good to get people thinking about these things. Thanks for your input. Simon

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