Grass-fed doesn’t really scale and entails a number of other environmental issues from higher methane to higher deforestation. Even for Ireland in particular, it’s got quite a number of issues
Increased methane emissions
Grass-fed production requires longer growing times leading to more lifetime methane emissions overall. It also requires more cattle overall due to lower slaughter weight
Taken together, an exclusively grass-fed beef cattle herd would raise the United States’ total methane emissions by approximately 8%.
Not enough land to meet demand even if 100% of grassland was used
We model a nationwide transition [in the US] from grain- to grass-finishing systems using demographics of present-day beef cattle. In order to produce the same quantity of beef as the present-day system, we find that a nationwide shift to exclusively grass-fed beef would require increasing the national cattle herd from 77 to 100 million cattle, an increase of 30%. We also find that the current pastureland grass resource can support only 27% of the current beef supply (27 million cattle), an amount 30% smaller than prior estimates
[…]
If beef consumption is not reduced and is instead satisfied by greater imports of grass-fed beef, a switch to purely grass-fed systems would likely result in higher environmental costs, including higher overall
methane emissions. Thus, only reductions in beef consumption can guarantee reductions in the environmental impact of US food systems.
Problems in countries that have tried to scale it up
New Zealand has tried to scale up it’s grass-fed production and often touts it. To do so, they end up using heavy amounts of fertilizer in their production so much so that some regions need a 12-fold reduction in their dairy industry size just to have their water meet safety thresholds
The large footprint for milk in Canterbury indicates just how far the capacity of the environment has been overshot. To maintain that level of production and have healthy water would require either 12 times more rainfall in the region or a 12-fold reduction in cows.
[…]
The “grass-fed” marketing line overlooks the huge amounts of fossil-fuel-derived fertiliser used to make the extra grass that supports New Zealand’s very high animal stock rates.
Keep in mind that this is the case with New Zealand still using plenty of feed because their definition of grass-fed still allows for plenty of supplemental grain. A fully grass-fed system would fair even worse in that regard
The national dairy industry [in New Zealand] is consistently the country’s largest consumer of grain and feed at approximately 75 percent (Figure 4). The majority of dairy farms are on non-irrigated pasture-based systems (75 to 80 percent), where up to 25 percent of the annual diet could consist of supplemental feeding. With the recently high dairy prices experienced of over NZ$9.30 (US$6.05) in the last two years (Appendix 2), farmers have looked to maximize milk yields by utilizing more “purchased” feed for conversion to milk solids
In the UK and Ireland, the land that grass-fed cows are on is primarily actually not natural grass-land - its natural state is temperate rainforest
Most of the UK and Ireland’s grass-fed cows and sheep are on land that might otherwise be temperate rainforest – arable crops tend to prefer drier conditions. However, even if there were no livestock grazing in the rainforest zone – and these areas were threatened by other crops instead – livestock would still pose an indirect threat due to their huge land footprint
[…]
Furthermore, most British grass-fed cows are still fed crops on top of their staple grass
The source looking at Ireland does talk about how sheep grazing in the UK and Ireland are primarily on temperate forestland. But more broadly, other ruminants like sheep are going to have similarly high methane emissions to cattle. Ruminants, unlike other farm animals, have most of their emission from eccentric fermentation (and or land use change/deforestation) which is going to occur at similar rates when they are eating grass as well. So should I have separated that out a bit, potentially yes, but my earlier comments were already getting quite long
From one study:
More than 80% of the emissions attributed to sheepmeat and wool result from on-farm methane emissions, due principally to enteric fermentation (Cottle et al., 2016, Peri et al., 2020, Vermulen et al., 2012). Other non-methane emissions and emissions that occur in the supply chain post farm gate are a relatively minor contributor to overall emissions (Australian Government, 2020, Vermulen et al., 2012).
In terms of land usage, the land usage is actually even higher for lamb and mutton production per kg and per kg protein compared to the already high usage for beef production [1] [2]. This entails wool production having high usage since sheep in wool production are typically killed for meat as well once their wool production decrease (similar to dairy).
When we compare wool emissions to other textiles, we find that wool has some of the highest emissions per kg of any textile [3]. We could just as easily be using cotton (lower emissions to produce per kg) which has similar insulation R values and lower emissions
Ah no worries, I have a tendency to just dump a lot into comments so it might be easy to miss some of the details. My infodumping tendencies have their cons sometimes :)
Grass-fed doesn’t really scale and entails a number of other environmental issues from higher methane to higher deforestation. Even for Ireland in particular, it’s got quite a number of issues
Increased methane emissions
Grass-fed production requires longer growing times leading to more lifetime methane emissions overall. It also requires more cattle overall due to lower slaughter weight
https://iopscience.iop.org/article/10.1088/1748-9326/aad401/pdf
Not enough land to meet demand even if 100% of grassland was used
https://iopscience.iop.org/article/10.1088/1748-9326/aad401
Problems in countries that have tried to scale it up
New Zealand has tried to scale up it’s grass-fed production and often touts it. To do so, they end up using heavy amounts of fertilizer in their production so much so that some regions need a 12-fold reduction in their dairy industry size just to have their water meet safety thresholds
https://theconversation.com/11-000-litres-of-water-to-make-one-litre-of-milk-new-questions-about-the-freshwater-impact-of-nz-dairy-farming-183806
Keep in mind that this is the case with New Zealand still using plenty of feed because their definition of grass-fed still allows for plenty of supplemental grain. A fully grass-fed system would fair even worse in that regard
(emphasis mine)
https://apps.fas.usda.gov/newgainapi/api/Report/DownloadReportByFileName?fileName=New Zealand Grain and Feed Market Situation_Wellington_New Zealand_NZ2023-0003.pdf
Problems with grass-fed production in Ireland
In the UK and Ireland, the land that grass-fed cows are on is primarily actually not natural grass-land - its natural state is temperate rainforest
https://theconversation.com/livestock-grazing-is-preventing-the-return-of-rainforests-to-the-uk-and-ireland-198014
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The source looking at Ireland does talk about how sheep grazing in the UK and Ireland are primarily on temperate forestland. But more broadly, other ruminants like sheep are going to have similarly high methane emissions to cattle. Ruminants, unlike other farm animals, have most of their emission from eccentric fermentation (and or land use change/deforestation) which is going to occur at similar rates when they are eating grass as well. So should I have separated that out a bit, potentially yes, but my earlier comments were already getting quite long
From one study:
https://www.sciencedirect.com/science/article/pii/S1751731122000416#s0050
In terms of land usage, the land usage is actually even higher for lamb and mutton production per kg and per kg protein compared to the already high usage for beef production [1] [2]. This entails wool production having high usage since sheep in wool production are typically killed for meat as well once their wool production decrease (similar to dairy).
When we compare wool emissions to other textiles, we find that wool has some of the highest emissions per kg of any textile [3]. We could just as easily be using cotton (lower emissions to produce per kg) which has similar insulation R values and lower emissions
[1] https://ourworldindata.org/grapher/land-use-per-kg-poore
[2] https://ourworldindata.org/grapher/land-use-protein-poore
[3] https://www.researchgate.net/figure/ndustrial-carbon-footprint-of-textile-fabrics-in-this-study-kgCO-2-e-kg_tbl1_303634993 along with other studies all showing the same trends of other regions with wool as a great outlier in terms of emissions. The emissions don’t seem to vary much from what I have read even when looking at regions with mostly all pasture-based production
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Ah no worries, I have a tendency to just dump a lot into comments so it might be easy to miss some of the details. My infodumping tendencies have their cons sometimes :)
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