Frederic Leroy: Skärningspunkten mellan miljö, hälsa och kost

Senast ändrad: 18 oktober 2021

Frederic Leroy från Vrije Universiteit i Belgien föreläste via Zoom under rubriken ”Skärningspunkten mellan miljö och hälsa. Och nyttan av holistiskt tänkande snarare än fokus på konflikten mellan animalie- eller växt-baserad kost.” Här kan du se hela den välbesökta föreläsningen, titta igenom presentationen och läsa svar de frågor som Frederic inte hann besvara under föreläsningen.

Se Frederics presentation här The intersection of environment and health

Frågor ställda till Frederic


  1. Most reports regarding emissions use GWP100 for methane which is the effect of methane for a span of 100 years. As you mentioned, it is "short-lived" gas which makes the use of GWP100 for methane quite misleading. GWP20 would be better as it would represent the effect of methane better, but then, the effect of methane is multiplied by 3. Counting with GWP20, reducing the meat consumption has a much larger impact on an individual level. GWP20 is more truthful to the actual effect, than GWP100, and the methane emissions from livestock are increasing per year, so I fail to find a reason to use GWP100 and I could not find such online. Instead, I found people who thought the same as me. I believe it is very important to know this fact when advocating for ruminant meat. What are your thought on this?

Different time horizons offer different perspectives, so it depends on what policy question we are looking at. One metric that is of crucial importance with respect to the methane/warming issue is GWP* (work of Myles Allan, Oxford Martin): This demonstrates that slightly reducing the herd’s methane emissions (0.3% per year) would correspond with zero CO2-warming-equivalent emissions and, therefore, not cause further global warming in aggregate. Some call this ‘creative accountancy’ but I don’t agree, this addresses the mechanistic background much better when talking about warming of very different gasses – we need to use the right metrics to address the right questions.

The CH4 emissions are indeed increasing but that is not necessarily a livestock effect:



But I do agree that it is fair to say that livestock emissions are increasing in some parts of the world. Particularly so in developing countries, while they are stable or decreasing in industrialized countries. That being said – the latter trend in the West should and can continue for carbon neutrality, and may even create a global cooling effect (as long as it’s not unfairly used, just to ‘win time for fossil fuels’). Also, we really need to look beyond emissions and also consider sequestration in agricultural lands. Check New Zealand, now heading for carbon neutrality:

  1. You mentioned margarine and how they advertised the same way. To me, the comparison of mock meats to margarine is unfair. The reason is that the knowledge of fats back then was very limited and oils that would not be used today in most countries were used to make old margarine. I understand the point, but the mock meats intend to mimic the matrix of meats and old margarine just tried to sell extremely cheap fats for a good price. I do see the connection with adding value to the product though. I think a good improvement would be to list the ingredients of the margarine on the slide? I don't advocate mock meats by the way. It is an interesting "nice to have" option with a potentially lower environmental impact than all types of beef according to studies comparing meat types, but not a "must have".

The similarity in both cases is that of a new business opportunity (hence multinationals jumping on the matter) and the need to create a marketing “narrative” to be able to get away with it publicly (and to make the imitation “better” than the original for reasons of “modernity”, but at the same time claiming sensory equivalency). Margarine did try to “mock” butter, and was meant to displace it. It was at some point forbidden to colour it yellow - manufacturers would then sell margarine in plastic bags with a separate dye that consumers then had to knead into the spread 😊

  1. Manure from cattle unfortunately leaks to waterways. There is just too much manure in general. In Sweden, in the 80s, it lead to acidification and algal bloom in waterways. The result was that the reproduction rate of wild fish became extremely low. So while Multi Padock Grazing systems may lead to some increase in plant biodiversity, which potentially aids bees, it ruins the biodiversity in waterways. The way Sweden solved this issue was by making use of the mining industry - to mine for limestone and treat waterways by countering the effects of manure. This affects the environment negatively of course and taxpayers with a fee of 17 million euros per year. By factoring in this, the system becomes more complex of course, but it may be useful to know.

Manure and water quality are certainly problems. Yet, well-managed cattle will improve soil health, increase water infiltration and retention, and reduce runoff into waterways. I’m surprised that you specifically mention AMP grazing, which is generally doing better at this level than conventional systems. But the idea is also valid for non-AMP systems, for instance by better crop-livestock integration.

In my view, water quality and N/P cycles are indeed valid concerns and its outcomes should help shaping the systems in place towards improvement. But that’s also true for plant agriculture! In Brittany (France), nitrate levels of surface and groundwaters decreased despite the high density of livestock, while increases are seen in specialized crop areas (>limit) Praxis, once more, is key – rather than “animals vs. plants”.


4. "What is your position on the EU methane strategy, do you expect to somehow replicate to Teagasc navigator approach to establish a roadmap to meet national targets, or what do you expect ta happend in this context - what would be annouced to the farmers - breeders in the future. I try to be activite in this field in my country - Slovakia, also participating in the EIP Agri subgroup on innovation" my activity profile:

The Teagasc navigator is one towards higher efficiency – of which many strategies are indeed realistically achievable and recommendable (feed strategies and feed additives, veterinary care, genetics, smart use of manure, herd management, re-use of meat-processing by-products, valorization of biogas, …) -  and has a focus on “cutting” rather than “counting as such”. Using the GWP* framework, cutting emissions means that this would lead to either a zero contribution to warming (obtained with a 0.3% decrease in emissions per year) or even create global cooling at higher rates. There is room for such improvement, and I can but encourage to do what is feasible (but not to the degree that it would undermine the feasibility of farming, as that would come with very detrimental tradeoffs on a larger societal level). Also, when evaluating the role of livestock in carbon footprints, we really need to look better at what is being offset by sequestration in grasslands or use of vegetation. Check how New Zealand in now on path to carbon neutrality: Thanks for the link, will have a look!



Margareta Emanuelson
Universitetslektor, Institutionen för husdjurens utfodring och vård
Koordinator för Hållbara dieter från hållbara produktionssystem, 018-67 16 49, 0703-35 74 70