The Answer Lies in the Soil

As Arthur Fallowfield, the farmer character in the legendary Radio 4 comedy series’ Beyond our Ken and Round the Horne, would have said, “The arnswer loies in the soil”.

I read with interest and increasing disbelief, an article by George Monbiot in yesterday’s Guardian. George, who I hold in very high regard, claimed that eating a kilo of Beef or Lamb, especially if it’s from animals that have lived in the uplands of Britain, had the same carbon footprint as an individual flying to New York. George also couldn’t quite believe what he was reading and contacted the author for more information. You can find the calculations at the bottom of George’s piece on his own blog (not the Guardian version.)

I had a look at the paper the figures were based on – as I don’t have access to scientific references for free I wasn’t able to see where George had got his figures from, but the paper was published in the Journal of Agricultural Science. The paper compares the carbon footprint of cattle and sheep from 2 upland farms in the Cambrian mountains of Wales – and was received for peer review in February 2009. And yes, using these figures, you can get to the astonishingly high carbon footprints George mentions in his article.

But the story does not end there.

18 months later the same author, Professor Gareth Edwards-Jones, published a much larger more comprehensive study of 20 upland farms in the Cambrian Mountains. This was published as a CCW policy research report in September 2010. This gives quite a different – in some cases completely polar opposite, picture to the one George has painted.

On three of the 20 farms where the study took place, the production of cattle and sheep caused a net sequestration of Carbon. Yes, that’s right. Producing lamb and beef can actually lead to the storage of Carbon. How could this be?

The answer really does lie in the soil. Soils, mostly under grassland, are the UK’s second largest carbon store, after peatlands. One third of the UK’s Carbon is stored in grassland soils, many of them in upland areas. The capacity for grasslands to store carbon depends on a number of things, including how they are managed. Grassland soils can also release the very potent greenhouse gas Nitrous Oxide, again depending on how they are managed – or example whether artificial Nitrogen fertiliser is applied. So how upland grasslands are managed has a huge impact on the carbon footprint of the animals, and therefore the meat, which is produced there.

As the Edward-Jones research found, this carbon footprint can range from 4 to 17 kgCO2e/ha for a kilo of lamb (liveweight) and 4 to 23 kgCO2e/ha for beef (table 3), before the Carbon sequestration happening in the grassland soils of the farm is even taken into account. Edwards-Jones did not calculate the per kilo carbon footprint after sequestration. He also used a conservative estimate of the capacity of grasslands to absorb carbon. Had he used a slightly less conservative estimate of carbon sequestration another 3 farms out of 20 may have been shown to be net Carbon sinks (table 9).

Time and again in the CCW paper, the authors point out how little research has been done into Carbon storage and sequestration in grasslands. Which is extraordinary when you consider that this is far and away the most important factor in determining the carbon footprint of meat from livestock. What is known is that wildlife-rich grasslands are known to contain high levels of carbon in their soils – up to 438 tonnes C per ha (that’s equivalent to over 1700 tones of CO2e), far higher than agriculturally improved ones. And converting arable or improved grasslands back to wildlife-rich ones causes them to rapidly absorb carbon, one study found at over 3 tonnes per ha per annum, while continuing to provide grazing/fodder for livestock.

It seems strange that this very important piece of work was not published in a scientific paper. Sadly the reason was that Professor Edwards-Jones died of cancer in August 2011.

The problem with treating upland farming as one “thing” is that you end up with simplistic pictures of their environmental impacts, costs and benefits.  Even among the 20 farms within the Cambrian Mountains research study there is huge variation. That variation will be reflected in other parts of upland Britain. But one thing does appear to be consistent – that uplands that support semi-natural habitats – wildlife-rich grasslands, upland heathland, peatland, mires, scrub and so on – are net carbon sinks, hold water back to prevent downstream flooding, produce high quality food, and provide homes for some of our most threatened wildlife.

They are very different from other uplands (which form the majority) – the uplands overgrazed in the past and to a lesser extent today, supporting very degraded upland acid grassland, or grasslands that have been agriculturally improved.

While there may be good arguments for rewilding some uplands, the carbon footprint of meat produced there, amongst other factors, would indicate that some uplands are better for rewilding; and others need to be cherished for what they are now.

About Miles King

UK conservation professional, writing about nature, politics, life. All views are my own and not my employers. I don't write on behalf of anybody else.
This entry was posted in agriculture, carbon storage, George Monbiot, grasslands, grazing, uplands and tagged , , , . Bookmark the permalink.

13 Responses to The Answer Lies in the Soil

  1. Looking forward to a stimulating back and forth on this very important topic.

  2. Wendy Birks says:

    Perhaps the answer is to give up on tradtitional forms of farming animals for meat and have all the uplands rewilded, then obtain meat by culling a “sustainable” percentage of the edible wild animals, whatever species they happen to be? That way you’d get the maximum carbon storage and a meat supply.

  3. Jack Lane says:

    A very thoughtful and reasoned response to George Monbiot’s piece. Mr Monbiot is a vital writer in my opinion and I expect will welcome the points raised by Mr King.

  4. Mark Fisher says:

    Festive Greetings, Miles. Not sure I fully follow your distinctions between “good” and “bad” uplands, but having looked at the 2009 paper (which I will send you) there is a recognition that “case study farm 2” is very different from the other, its extensive production system appearing to have a very high carbon footprint per kg of lamb produced:
    “Most of the emissions arise from the organic soil, and are outside the control of the farmer. In addition this farm has adopted much of the environmental advice given to farmers over the last 25 years. The low stocking rate is perhaps the most obvious indicator of this. However, when viewed from the perspective of a carbon footprint this low stocking rate relates to low production efficiency, which then delivers high GHG emissions per functional unit. This highlights the potential conflict between carbon efficiencies and other environmental objectives”

    Hmmm – probably why I steer clear of discussions about GHG, climate change and sloppy peat. The bottom line for me is that I don’t eat sheep meat anyway, nor grouse, and so the sheepwrecked moorland immediately above my house has nothing to offer me, and especially this morning when I had a stream running through my garden because of surface run off!

    I noticed someone had hash tagged their comment on George’s article with “#justlostallcredibility”. I’m afraid, apart from the usual loonies, this type of judgement has been creeping into the comments on his recent articles. I was a bit annoyed that George gave Ennerdale as an exemplar in his article about flooding on 7 Dec. He implied that “engineering works” had been removed from the River Liza in the valley – wrong, it was just one “Ireland” bridge from Woundell Beck that drains into the Liza, and which is then canalised until it reaches the lake. He then said the Liza was “allowed to braid, meander” giving a reference to one of our MSc students, and which actually says:
    “Within the present analysis it is impossible to determine whether there has been any change in the River Liza as a result of the Wild Ennerdale project initiation in 2003, although considering the small changes in land-use and the fact that the valley has only been subject to low-intensity land-use since the Bronze Age means significant changes are not anticipated”

    It is likely that what you will increasingly see in the Ennerdale Valley is an adding to the natural erosion of the river bank from the increasing HLS subsidised ranging of cattle (remember this is part of England’s Public Forest Estate!) except that the latter will be a breach of rule 11 of the proposed new basic rules for farmers to tackle diffuse water pollution from agriculture in England:
    “11. Exclude livestock from watercourses. Reduce pollution by stopping excreta dropping into watercourses or avoid river bank erosion leading to more sediment loss”

    Ah well!

    • Miles King says:

      Thanks Mark. Yes I understand that, using the international carbon foot printing standard called PAS2050, the extensive system in the study (which may or may not be HNV – we are not told) has a higher carbon footprint per kg of meat than the more intensive system. But when the far higher carbon sequestration rates for extensive systems are taken into account, the extensive farm footprint is much lower and in several of the case studies on the far larger study I referred to, becomes negative.

      Thanks for your comments on Ennerdale – I did wonder!

  5. John Mason says:

    An interesting read, Miles, with which I agree, especially with your critique of the “one size fits all” approach to the uplands. Mark and I have recently met at Skeptical Science and I can see where he’s at WRT this. My stamping-ground ranges from Dylife over to Plynlimon – I have spent years wandering it and there are so many different habitats up there and a wealth of evidence for past ones. There are so many factors that are important: aspect, bedrock geochemistry, drift geology, altitude. That tract has everything from mobile scree-slopes to acid moorland to old peat-diggings (with lots of bogwood and very occasional contemporary Beaker-period arrowheads) to, at height, Alpine-Arctic tundra. The sheep-clobbered stuff is just part of the picture.

    • Miles King says:

      Thanks very much John. It’s not an area I know at all well, but I’m glad for your description. It’s a pity that the Edwards-Jones CCW paper did not provide a vignette description for each of the 20 farms in the study. I suppose it might be possible to identify them from single payment data? The whole of Wales has had a habitat survey (at phase one) so semi-natural habitats such as upland Heath and blanket peat are mapped.

  6. John Mason says:

    I’ll do a blog-post with a set of images sometime soon – give you a flavour of what it’s like up here. Will make a nice change from repeat images of flooding!

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