More than 1,000 scientists with high levels of knowledge and expertise about the contribution livestock can make to human wellbeing and to the health of the planet have signed the Dublin Declaration, committing themselves to making their evidence-based arguments heard in the public square.

At the end of the first quarter of 2023, the United Nations Agency the Food and Agriculture Organisation (FAO) gave new estimates for cattle slaughter and availability of hides. Its figures offer a comparison between 2020 and 2021, the most recent years for which these statistics are available. The Rome- based organisation has put the global cattle herd size at just over 1.5 billion head in 2021, up very slightly, by 0.4%, on the figure for 2020.

It has estimated the total number of raw cattle hides that the meat and livestock sector generated in 2021 at 331.9 million, which is an increase of 1% compared to its estimate for 2020. We know that millions of these hides will have gone to waste. As an illustrative figure, the Leather and Hide Council of America has calculated that only around 55% of the world’s supply of hides makes its way into the leather value chain. This may be a painful truth for the global leather industry, but it is also possible to look at it from the opposite point of view: if 55% of those hides do make their way into the leather value chain, a nine-digit number will continue to be needed to show the volume of hides going into tanning drums for the production of finished leather.

Cause for celebration

As long as livestock farming continues, hundreds of millions of hides are going to be available every year for humanity to use to produce material for shoes, bags, furniture, car upholstery, clothing, interior design, gloves, aircraft interiors and many other applications. If people are sincere about limiting the production and use of plastic, it may not be long before making these products from leather instead becomes a genuine cause for celebration in the eyes of millions of consumers. This could only prove less than true if livestock farming were to become a thing of the past. Livestock farming is changing (increasing the yield of meat and milk while reducing emissions), but it is not going away. Far from it. It is here to stay, and so is leather.

In addition to the FAO figures, another cause for confidence about the future of cattle farming and, therefore, about hide availability is an increase in the number and the stature of the people who are speaking up for meat and livestock in the public domain. At the end of 2022, hundreds of scientists signed a pledge to support and contribute to efforts to show scientifically that livestock farming brings benefits to society. This pledge has become known as the Dublin Declaration. These scientists support it because they want to increase availability of healthy and safe food with high nutritional values as the global population grows. At the same time, they want to make sure animal production systems are sustainable.

Precious resource

“Livestock systems must progress on the basis of the highest scientific standards,” they have said. “They are too precious to society to become the victim of simplification, reductionism or zealotry.” Signatories also explained that by recycling “the large amounts of inedible biomass that are generated as by-products”, farmed and herded animals “are irreplaceable for maintaining a circular flow of materials”. Further along the value chain, leather is part of that picture, too. Within days of its launch, the Dublin Declaration had more than 300 signatories, with scientists from South America, North America, Africa, Europe, India, Australia and New Zealand pledging support. By the start of June 2023, this figure had increased to 1,065 scientists from 63 countries.

Three of these signatories took part in a discussion that multi-stakeholder group European Livestock Voice hosted in Zaragoza in northern Spain at the end of March. The focus of the discussion was to examine what the future holds for the livestock industry in Europe in the context of the European Union’s Green Deal and its 2020 Farm To Fork strategy. The trio of Dublin Declaration signatories presented arguments from two different perspectives, nutrition and the environment, in favour of the continuation of livestock farming.

For Professor Alice Stanton, an expert in cardiovascular medicine, member of the Royal College of Surgeons in Ireland and a contributor to Ireland’s national food strategy programme, the challenge is to find ways to provide the entire global population with affordable access to varied, nutrient-rich whole foods that are produced sustainably from plants and from animals. She contrasts whole foods with those that are ultra- processed. As in most things, there is a spectrum here, but the FAO has a four- step classification system called NOVA with whole foods at grade one and ultra- processed at grade four. “For grade four,” Professor Stanton explains, “multiple industrial processes have occurred to the food, so much so that the original source is not recognisable.” Sweet foods, junk foods, pasta sauces, biscuits and so on are all in this category. They contain multiple additives, colourants and flavours, particularly excess salt, sugar and trans fats, the professor points out.
What she refers to as “the huge crisis that is facing our populations” is that, in the western world and, increasingly in low- and middle-income economies, up to 60% of the calories that people consume are from ultra-processed food. “Manufacturers even use multiple chemicals to glue these foods together,”

Professor Stanton says. “And, yes, 60% of calories that people consume in the US and in excess of 50% in the EU are from ultra-processed foods.”

Under attack

She has no objection to Farm To Fork’s contention that, in general, people are eating too much of some foods and too little of others, notably fruit, vegetables, legumes, nuts and seeds. But she views as unbalanced Farm To Fork’s insistence on citing red meat as one of the food categories that consumers should cut back on. The original Farm To Fork strategy document from 2020 says: “Current food consumption patterns are unsustainable from both health and environmental points of view. While in the EU, average intakes of energy, red meat, sugars, salt and fats continue to exceed recommendations, consumption of whole-grain cereals, fruit, vegetables, legumes and nuts is insufficient.” Trans fats and ultra-processed foods merit no specific mention here, Professor Stanton points out, while in her eyes the text represents one of many instances of red meat coming “under particular attack”.

In 2007 the health authorities in the UK presented eating recommendations that came to be called the ‘Eat Well Plate’. In these recommendations, at least 25% of all calories were from animal-source foods. By 2019, when the EAT-Lancet Commission published, to great fanfare, its ‘Planetary Health Diet’, the recommendation for calories from animal sources had fallen to 12%, with 6% coming from meat, fish and eggs, and 6% from dairy. But there are some grounds for optimism, Professor Stanton points out. “Some of the authors of the Eat-Lancet reference diet have come out in public and said that the Eat-Lancet reference diet is inadequate for micronutrients,” she says. “And they have proposed that the adequate diet for adults should, once again, have a minimum of 25% of calories coming from livestock foods, with red meat going up from 1% of the diet up to 4%. The next version of the Eat-Lancet reference diet will be much more flexible.”

The authors she refers to include Dr Jessica Fanzo, professor of global food policy and ethics at Johns Hopkins University in Baltimore. Dr Fanzo contributed to a paper with the title ‘Estimated micronutrient shortfalls of the EAT-Lancet Planetary Health Diet’, published in March this year. To its credit, the journal that carried this paper was The Lancet in its Planetary Health journal. “Dr Fanzo was a member of the first Eat-Lancet Commission and is also a member of the second,” Professor Stanton says.

Health risks

In the view of the Irish cardiologist, a healthy diet needs to do two things: protect people against nutritional deficiencies and lower the risk of serious health impacts, including cancer, heart disease and strokes. She draws attention to studies on these subjects in which red meat has, again, come under attack, notably the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD), led by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington. The IHME presents these studies as “the most detailed scientific effort ever conducted to quantify levels and trends in health”. The original GBD analysis appeared in 1990 and used what IHME now regards as “very simple methods”. A 2017 GBD study was the first to use a new forecasting approach. It said excessive consumption of red meat was associated with 25,000 deaths. The 2017 study highlighted 15 dietary risk factors and red meat was the least important of them. In a follow-up GBD study in 2019, the conclusion was that red meat was associated with almost 900,000 deaths, a figure 36 times higher. The 2019 study suggested that any consumption of red meat at all was a health risk.

A group of scientists, including Dublin Declaration signatories and Zaragoza panellists Alice Stanton and Frédéric Leroy, a professor in food science and biotechnology at Brussels Free University, questioned the 2019 GBD conclusion. “We wanted to know if this was reliable,” Professor Stanton says, “and to ask where the evidence was. We also wanted to know what would happen with [dietary] deficiency deaths if any red meat consumption was regarded as harmful. We were joined by the World Cancer Research Fund and the Academy of Nutritional Sciences in saying GBD had to produce the evidence and that we had to be able to interrogate it, and we eventually got our letter published in The Lancet [in April 2022].”

In the three years in which the 2019 GBD analysis had gone largely unchallenged, the report was cited in hundreds of articles and scientific papers and nine policy documents. On October 10, 2022, the GBD collaborators published a paper in the journal Nature Medicine with the title ‘Health effects associated with consumption of unprocessed red meat: a Burden of Proof study’, resulting in what Professor Stanton calls very different conclusions. She explains: “What they said in this paper was there is little or no evidence that red meat causes any harm whatsoever and that the weak evidence that is there is certainly insufficient to make any policy recommendations or decisions. The optimal intake of red meat is certainly not zero and could be as high as 200 grammes per day.”

Food diversification

It is early days, but the Nature Medicine paper presenting these different conclusions only had 18 citations by early this June. The original message seems to have filtered much more readily into the public consciousness. This is in spite of the tireless efforts of Professor Frédéric Leroy to secure a fairer hearing for meat and livestock on social media.

He is interested in all kinds of foods and likens the bugs he has tried to the shrimps available on Belgium’s North Sea coast. “They’re a bit dry, but crunchy,” he says. “You could have them as an appetiser, but you could never feed yourself entirely on insects within our cultural frameworks.” Professor Leroy says he respects the search for alternatives to meat. He is “all for diversification”, and for offering more choices in people’s diets “as long as they fit the criteria”. These choices must offer food that is nutritious and can be sustainably produced. He divides the alternatives that are emerging into different categories. “We have to distinguish between them because they come with different implications,” he explains.

With regard to the first category, laboratory-produced meat substitutes, he says these products will not become a regular part of many people’s diets in the near future, if they ever do. “The technology involved comes from the medical field,” he says, “and there are serious bottlenecks in place with respect to upscaling the whole process. I think it’s a non-discussion at the moment.”

Plant-based fast-food represents the second category. He describes these products in this way because they are usually, if not always, “on the ultra- processed side” and are presented as part of fast-food culture. “They often come in the form of burgers and sausages, foods that people will put lots of sauce on and put in a bun. You can hardly taste the original food; the original taste is masked because it is not very attractive and that’s because the food comes from protein isolates that are processed to a point at which they become palatable and they are then hidden in fast-food condiments. I don’t see this as particularly beneficial.” Frédéric Leroy views this connection to fast-food culture and its dependence on ultra-processed food as something that “amplifies the problem we’re already facing”.

The third category is insects. Insects have long been part of human diets but here again scaling up production and consumption of insect-based food is going to be a challenge. The barriers in this case may be more cultural than technological, the professor concedes, although the technology is not straightforward and also subject to bottlenecks. Instead, his view is that people who want to have a plant-based diet can and should still make the shift away from processed and ultra- processed foods to whole foods a key part of the dietary change. “There are plenty of recipes already in our culinary heritage that are based on plants and we could use these instead,” he argues.

Help from herbivores

A vegetation ecologist who has become a specialist in the environment and livestock, Dr Pablo Manzano works at a research institute called the Basque Centre for Climate Change near Bilbao. He too is a signatory of the Dublin Declaration. He picks up the gauntlet of defending livestock farming (and, by extension, meat and leather production) against attack on environmental grounds. The European Commission describes Farm To Fork as being “at the heart of the Green Deal”, and in the Green Deal, it says it wants Europe to become “the first climate-neutral continent” by 2050.

If the suggestion that red meat is bad for human health is tough to uproot from public consciousness in the 2020s, the suggestion that livestock farming is a major threat to the environment is probably even tougher. Messages that activist Greta Thunberg tweets to her 5.5 million followers, for example that if current agricultural systems remain in place we will run out of land and food, are hard to counter in a few words. It is definitely a challenge to transmit “the complexity of the issues”, Dr Manzano says. But he has a try anyway. “I always say that the best animal production system outperforms the best crop system by far,” he says. “But  the  worst  animal  production system is outperformed by far by the worst crop production system.” He points out that, outside vegetation ecologist circles (there are only around 400 of them around the world, he reckons) little is known and understood about the role that herbivores have played in shaping our planet over the last 15 million years. “If we want functional landscapes, we need a lot of herbivores,” he contends. “There used to be big herds of herbivores migrating around. Now we have very few ecosystems that conserve that.”

He points to the Serengeti ecosystem in Tanzania as one of only a few exceptions to this. What he says he has learned from observing this ecosystem so far is: “If we can imitate those primeval systems of herbivores, we are going to match high sustainability in terms of biodiversity and ecosystem functionality. And even if it is going to be expensive, because it’s true that, for example, mobile pastoralism or regenerative adaptive grazing have higher demands on manpower, they are also able to achieve higher productivities. This is also something that is not well understood.”

Rural communities

It could also improve food security and food sovereignty, including in the European Union. This may make food more expensive, but Dr Manzano’s view is that most countries in Europe can afford to pay more for good food and that many consumers will support this if it genuinely promotes (in the face of huge challenges in countries including France, Italy and Spain of rural unemployment, rural poverty and rural depopulation) more vibrant rural societies. Consumers on lower incomes can receive support to have access to the high-quality, nutritionally balanced food these rural communities will produce and there will be more income in the places the food comes from.

Making this vision a reality will do nothing to harm Europe’s prospects of becoming carbon neutral by 2050. But this, too, is complex, Pablo Manzano explains, not least because of the layers of complexity in the way greenhouse gas emissions are accounted for in current calculations. “Herbivores are an ecological niche,” he says. “The methane that is emitted in those natural systems has to do with the amount of cellulose that is in the diet. We know that one way to reduce greenhouse gas emissions is to reduce the amount of cellulose in the rations that animals get.”

The Basque Centre for Climate Change has carried out a study to compare emissions in the Serengeti ecosystem with those in neighbouring areas in which Maasai peoples keep livestock with very low input. In the study, the emissions per hectare in the Serengeti, which came from the wildebeest, zebra and buffalo that roam there, and the emissions from the Maasai peoples’ sheep, goats and cows in the neighbouring area were the same. “Not 90%, not 80%,” Dr Manzano insists, “exactly the same. According to our data, the emissions per hectare from the cows, goats and sheep, and emissions per hectare from the wildebeest, zebra and buffalo were the same.”

Imitate nature

He says this means that the emissions from the domestic livestock cannot be considered anthropogenic. If the Maasai peoples were to stop raising their domestic animals on the neighbouring grasslands, wild herbivores would arrive from the Serengeti to eat the grass. The cellulose would prove irresistible to them and the same amount of methane would be emitted. “It is logical,” Dr Manzano says. “These emissions are part of the natural ecosystem. So these graphs that we see in our data that say that cows in Africa or in India are emitting a lot of methane are ignoring that this methane is part of the natural cycle of carbon and should not be counted as anthropogenic greenhouse gas emissions.”

We can and must achieve sustainable livestock production, and Dr Manzano concludes that this can happen with the current numbers of livestock that the FAO figures quoted at the start of this article provide. The numbers are at the same levels as nature produced and supported 100,000 years ago, he insists. “Yes, we have to alter the ways in which we are producing livestock,” he says, “but we can achieve that. It’s all about imitating what nature has done for the last 15 million years.”
Professor Frédéric Leroy explains that the whole point of the Dublin Declaration is for scientists working on questions surrounding livestock farming to bring balance to the debates and discussions, and for evidence-based approaches to have prominence. “Things can move if we insist on evidence,” he says, “but we have to mobilise the scientific community around this. Scientists are being intimidated, not to say bullied, by a few people with loud voices. With the Dublin Declaration, we have more than 1,000 scientists saying that we need more balance in the livestock debate. We want to be part of this conversation.”

Cattle on the Estância Coxilha ranch in southern Brazil.
Credit: Victor Wortmann

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