Taking Stock: The omnivore's dilemma

Butterfly chart showing the number of animals killed to produce one tonne of meat vs. the greenhouse gas emissions of producing that meat. They are inversely correlated.

What are the trade-offs between animal welfare and the environmental impact of meat?—Hannah Ritchie

Eating meat with a lower carbon footprint often means killing more animals and treating them more poorly.

[See the original article to view the references cited throughout.]

‘An increasing number of people would describe their dietary habits as “flexitarian” or “reducitarian.” These are people who still eat meat and dairy but are trying to reduce their consumption, often for environmental or ethical reasons. In the UK, there are more flexitarians than vegans, vegetarians, and pescetarians (who only eat fish) combined.

‘These ethically-conscious consumers still have a choice to make: what types of meat should they eat to reduce their environmental impact and reduce animal welfare costs?

It’s tempting to assume that what’s good for the planet is also good for the animal, but unfortunately, this is not the case. These two goals are often in conflict. What’s better for animal welfare is often worse for the environment, and vice versa. This is true across different types of livestock (for example, beef versus chicken) and across different ways of raising a specific animal (caged versus free-range hens).

‘This trade-off is easily missed. How consumers navigate this dilemma will depend on their values and priorities, including other things such as cost, taste, and their relationship with farmers and communities.

‘In this article, I’ll present some of the research on the trade-offs between environmental protection and animal welfare so that you can decide what you want to do when faced with this trade-off.

Swapping beef burgers for chicken burgers lowers your environmental footprint but is worse for animal welfare

‘Swap a beef burger for a chicken one, and you’ll cut the carbon footprint of your dinner by around 80%. The problem, however, is that you’ll need to kill 200 times as many chickens as cows to get the same amount of meat. An average chicken might produce around 1.7 kilograms of meat, while a cow produces around 360 kilograms.

‘This is true for other types of livestock, too. In the chart [above], I’ve shown each type of meat’s carbon footprint on the right and the number of animals killed to produce one tonne on the left. You can see the trade-off. Bigger animals—cows, pigs, and lambs—emit more greenhouse gases but produce much more meat per animal. Chicken and fish might have a low carbon footprint but are killed in much higher numbers.

‘The consequence is that many more smaller animals—chickens and fish—are slaughtered. As my colleague, Max Roser shows in another article, every day 200 million chickens and hundreds of millions of fish are killed, compared to several million pigs and sheep, and about 900,000 cows daily. . . .

To give these figures some context, the average person in the European Union consumes around 80 kilograms of meat per year. If all of this came from chicken meat, about 40 chickens would have to be killed per person. From beef, it would be less than one-sixth of a cow. That’s one cow every 6 or 7 years.

‘But it’s not just the number of lives that matters. The life of an average chicken is likely much worse than a cow's. Nearly all of the world’s chickens are factory-farmed. I’ve written about the painful conditions that many chickens experience throughout their lives. While it is certainly the case that some cattle will also experience poor standards of care, they’re more likely, on average, to have higher levels of welfare.

It is difficult to navigate this tradeoff. Swapping beef for chicken and fish will reduce your environmental footprint but at the cost of more animals living more painful lives.

Poorer welfare standards tend to have a lower carbon and land footprint

‘Some flexitarians will prioritize the environment and choose chicken. Others will favour animal welfare and go for beef. Some will try to balance both and go for pork.

The choice is then a simple one, right? Surely, organic pork is better for the animal and the environment. Or the free-range chickens are happy, healthy, and have the lowest impact.

Unfortunately not. These trade-offs also exist within any given type of meat.

Chicken
’Pack chickens in tiny cages, and you’ll need less land. Stop them from moving around, and they’ll “waste” less energy. Give them growth hormones, and they’ll gain weight much faster. This is better for the climate because it means they need less feed to reach their market weight, saving fertilizer, land, water and other resources, and will often lead to less manure, which is another source of greenhouse gas emissions. But, of course, all of these choices will make animal lives more miserable.

‘In a previous article, I examined how chicken breeds have changed over the last 50 years. “Fast-growing strains” of chicken—which gain weight more quickly—have become increasingly popular. . . . [A]fter 56 days, the typical broiler chicken in 2005 was more than four times heavier than the average chicken in the 1950s. This gives modern chickens various health problems but is ultimately better for the climate because of the feed efficiency reasons I explained above. . . .

‘A 2019 review by the European Commission—“Impact of animal breeding on GHG emissions and farm economics”—notes that the carbon footprint of chicken production has been falling in recent decades, almost entirely due to improvements in the rate at which chickens grow. It notes that “further improved growth rate has by far the highest potential to reduce the GHG emissions of broiler production.”

The trade-off for animal welfare is clear. The report suggests that one of the barriers to further reductions in greenhouse gas emissions is animal welfare concerns among consumers:

‘“During recent years, there has been a growing market demand for slow-growing broilers, which have perceived higher welfare, as an alternative to the fast-growing, energy-efficient broilers. [...] Growing such slow-growing lines would result in a substantial increase in GHG emissions and other environmental burdens due to increased feed consumption of the birds over the longer production cycle.”

Eggs
’What’s true of chickens is also true of eggs. Caged hens require fewer resources than free-range ones and, therefore, have a lower carbon footprint.

‘A study comparing caged, free-range, and organic hens in the UK found that the caged hens produced more eggs and needed less feed. This reduced their carbon footprint by around 16% per kilogram of egg. Studies in the Netherlands and the Czech Republic found the same: battery or caged hens had the lowest carbon footprint.

Beef
’The same principles apply to cows. More efficient agriculture tends to reduce environmental impacts, but it also comes at the cost of worse animal welfare.

‘Grass-fed beef tends to have a higher carbon footprint than grain-fed. A study by Daniel Blaustein-Rejto and colleagues found that the emissions from grass-fed beef were around 20% higher than from grain-fed cows. Exclusively grass-fed beef also uses more land, so the “carbon opportunity costs”—how much carbon could be sequestered if you weren’t using that land for farming—are higher. When Daniel Blaustein-Rejto and colleagues included these “missed” costs, the carbon footprint of grass-fed beef was 42% higher than grain-fed.

‘Most grain-fed cows spend at least part of their lives outdoors, where they are fed on grass, hay, and other forage. What’s different is that they are transitioned to a grain-fed diet towards the end of their lives. In that sense, “grain-finished” is a more accurate term. Grain-fed cows can experience discomfort in a few ways. First, they are often transported from the field to a feedlot, which can have a physical and mental toll. The noise and vibrations of the journey can be stressful, conditions can be cramped, and they can be deprived of feed and water. A poorly managed transition from grass to grains can cause digestive issues and discomfort. There are ways to reduce some of these negative impacts, but the overall welfare of grain-fed cows is probably lower than grass-fed.

‘Grain-fed cows tend to gain weight more quickly, which means they reach their “optimal” weight sooner and are bigger at the end of their lives. They convert more feed into meat compared to grass-fed cows, which is why the carbon footprint of grain-fed beef tends to be lower. Several studies have reported similar results.9

Pigs
’It’s a similar pattern for pigs.

‘In a paper published in Nature Food, Harriet Bartlett and colleagues studied the environmental impacts, welfare costs, and antibiotic use in 74 pig “breed-to-finishing systems” in the UK and 17 in Brazil. This is the stage of production where pigs are fed to reach market weight.

‘Overall, they found pretty large trade-offs in most of these systems. Farms with better animal welfare tended to emit more carbon and use more land. . . .

‘The study also found that the typical consumer labels on food products did not guarantee good outcomes. . . .

How to navigate animal welfare and environmental trade-offs
’What can consumers do if they want to navigate these tradeoffs?

‘Of course, reducing overall meat consumption will shrink your environmental footprint and prevent animal suffering at the same time. I chose this path and maximized its benefits by eventually going vegan. But I also understand that the world is not going to go vegan overnight.

‘Consumers will still have to face some tradeoffs, and the options they choose will depend on their own rankings of values and priorities. That might mean switching to chicken to reduce your carbon footprint, sticking with beef because you think animal welfare is more important, or accepting 15% higher emissions for free-range eggs compared to caged ones.

‘On the producer side, some trade-offs in these impacts are unavoidable. You cannot get a high-yielding chicken without the use of fast-growing strains.

But these trade-offs are not always inevitable: a small subset of farms have achieved both lower environmental impacts and good levels of animal care. The problem is that these examples are understudied. In fact, few studies have even identified them.

‘If we focus more research on how some systems balance these priorities, we might find insights that can be replicated elsewhere. The uncomfortable dilemma would not disappear completely, but it might ease this tension.’

ourworldindata.org | @OurworldInData | @_HannahRitchie

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How farming could become the ultimate climate-change tool—Bianca Nogrady

A generation of farmers and scientists are finding ways to sequester carbon in the soil while improving crop yields.

‘When it comes to carbon, humanity has two pressing problems. First, there’s too much of it in the atmosphere. The atmospheric concentration of carbon dioxide has increased by about 50% since the start of the industrial age, from 280 parts per million to nearly 420 parts per million in 2023 . . . . Much of that comes from the combustion of fossil fuels, but agriculture is a major contributor. Each year, around 13.7 billion tonnes of CO2 or equivalent greenhouse gases is released into the atmosphere by agricultural processes, with more than one-quarter of global greenhouse-gas emissions arising from food production.

‘The second carbon problem is that there isn’t enough of it in the soil. Soil carbon has been drastically depleted around the world, thanks to intensive farming practices that have been developed to feed the growing population. One estimate suggests that around 133 billion tonnes of carbon—about 8% of total organic soil carbon—has been lost from the top 2 metres of soil since the advent of agriculture some 12,000 years ago. Around one-third of that loss has occurred since the Industrial Revolution in the 1800s.

This imbalance means that agriculture has an ace up its sleeve: although it’s currently a carbon source, it also has the potential to be a carbon sink, which could alter the planet’s climate-change trajectory . . . .

It’s not only possible, but it’s relatively easy to recharge soil organic carbon stocks by supporting and enhancing the natural processes that draw and convert CO2 into soil carbon.

The latest Intergovernmental Panel on Climate Change (IPCC) synthesis report puts carbon sequestration in agriculture as one of the highest potential contributions to reducing net emissions.

At around 3.5 gigatonnes of CO2 or its equivalent greenhouse gases per year, this is greater than the emissions from the entire European Union in 2022—exceeded only by a conversion of current energy supplies to solar or wind energy, or reduced destruction of natural ecosystems.

The challenge is to ensure that this happens fast enough, and at a low enough cost, for it to make a substantial contribution to achieving global net-zero carbon emissions by 2050.

‘The agricultural techniques that can help to increase soil carbon sequestration aren’t necessarily complex. But with the looming deadline of net-zero carbon emissions by 2050, as set by the Paris climate agreement, the pressure is on scientists to identify the most efficient, effective and rapidly scalable methods for soil carbon sequestration and how these can help to achieve the dual goals of mitigating climate change and improving soil health.

‘Soil organic carbon is the result of the CO2 that plants have extracted from the atmosphere and incorporated into their structure, especially root systems, being used to nourish other living organisms in the soil. . . .

‘The good news is that increasing soil carbon isn’t high tech. Evolution has already done most of the hard work by giving plants the ability to extract CO2 from the atmosphere through photosynthesis, turning it into carbohydrates and oxygen. The plants assimilate that carbon into their cells and tissues, which eventually become integrated into the soil when the plant sheds matter in the form of leaves, branches, flowers or fruit, or when it is consumed by other organisms, or when the plant dies and decomposes.

The biggest barrier to this process is humans and the bad habits that we have developed to squeeze better short-term yields out of soil.

‘[Deep ploughing] breaks up the soil, including the root systems of the crops and grasses, causing the release of CO2 into the atmosphere. Tilling also destroys the structure of the soil and increases the risk of erosion by wind or water, which can in turn cause more CO2 to be released.

‘Therefore, one way to potentially keep that carbon in the soil is to reduce or eliminate tilling in what’s called no-till or zero-till agriculture. Instead of turning over large amounts of soil to plant seeds or seedlings, farmers use equipment that creates either a narrow channel or a hole into which the seed or seedling can be planted. The residue of the previous season’s crop—stubble, stalks and stems, for example—is left in the soil and on the surface. The idea is that this reduces the disturbance of the soil structure and leaves more of the soil organic carbon in place.

‘Although carbon sequestration through no-till is promising, the evidence is mixed. Research suggests that the amount of soil carbon sequestered with no-till farming varies with climate and soil type. One analysis found evidence that the greatest increase in soil carbon with no-till agriculture occurred in warmer and wetter climates rather than in cooler and drier climates. However, less tilling does mean less fuel consumption—because farmers don’t have to plough as often and as deep—and therefore lower emissions. For example, the use of low-till farming in the United States is estimated to have saved the equivalent of around 3,500 million litres of diesel annually, enough to offset the annual CO2 emissions of around 1.7 million cars.

‘Another method to increase the retention of soil carbon is to grow cover crops alongside the main crop, instead of manually pulling up or poisoning weeds that appear. This keeps the root structure and its soil carbon contribution intact and in place. A study of two Australian vineyards found that allowing grasses to grow in between the rows of grape vines was associated with a nearly 23% increase in soil organic carbon over a 5-year period compared with the conventional method of using herbicide to control grass growth. . . .

‘There is also a growing interest in the carbon sequestration potential of adding inorganic, or mineral carbon, to agricultural soils through a process called enhanced weathering. This involves adding ground-up silicate rock, such as basalt, to the soil. The minerals in the rock dust—mainly magnesium and calcium—interact chemically with CO2 in the atmosphere to form carbonates, which remain in the soil in a solid form or dissolve and gradually drain out to the ocean through the water table.

‘A four-year study, which was published in February, of the US corn-belt region found that applying crushed basalt to maize (corn) and soya bean fields was associated with sequestration of an extra 10 tonnes of CO2 per hectare per year, while also increasing crop yields by 12–16%. . . .

‘Deforestation is another major contributor to agricultural sector carbon emissions, particularly in cattle farming, in which forests are bulldozed to create pastures for animals. Agroforestry—the integration of trees into farming systems—is one way to mitigate this problem. . . .

‘Soil scientist Rattan Lal, director of the Lal Carbon Center at Ohio State University in Columbus, says that if the world switches to non-fossil-fuel sources of energy, it will be possible to achieve a long-term positive soil carbon budget in which more carbon is absorbed by agriculture than is generated by it . . . .’

nature.com | @Nature | @BiancaNogrady

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Ray Kurzweil on how AI will transform the physical world

The changes will be particularly profound in energy, manufacturing and medicine, says the futurist

‘By the time children born today are in kindergarten, artificial intelligence (AI) will probably have surpassed humans at all cognitive tasks, from science to creativity. . . .

[AI] will bring countless benefits, but three areas have especially profound implications: energy, manufacturing and medicine. . . .

‘[H]arvesting just 0.01% of the sunlight the Earth receives would cover all human energy consumption. Since 1975, solar cells have become 99.7% cheaper per watt of capacity, allowing worldwide capacity to increase by around 2m times. So why doesn’t solar energy dominate yet? . . .The laws of physics suggest that massive improvements are possible, but the range of chemical possibilities to explore is so enormous that scientists have made achingly slow progress.

‘By contrast, ai can rapidly sift through billions of chemistries in simulation, and is already driving innovations in both photovoltaics and batteries. This is poised to accelerate dramatically. . . . Once vastly smarter AGI finds fully optimal materials, photovoltaic megaprojects will become viable and solar energy can be so abundant as to be almost free. . . .

‘After cheap, abundant solar energy, the next component is human labour, which is often backbreaking and dangerous. AI is making big strides in robotics that can greatly reduce labour costs. Robotics will also reduce raw-material extraction costs, and AI is finding ways to replace expensive rare-earth elements with common ones like zirconium, silicon and carbon-based graphene. Together, this means that most kinds of goods will become amazingly cheap and abundant.

‘These advanced manufacturing capabilities will allow the price-performance of computing to maintain the exponential trajectory of the past century—a 75-quadrillion-fold improvement since 1939. This is due to a feedback loop: today’s cutting-edge AI chips are used to optimise designs for next-generation chips. In terms of calculations per second per constant dollar, the best hardware available last November could do 48bn. Nvidia’s new b200 gpus exceed 500bn.

‘As we build the titanic computing power needed to simulate biology, we’ll unlock the third physical revolution from AI: medicine. . . .

AI is starting to turn medicine into an exact science.

‘Instead of painstaking trial-and-error in an experimental lab, molecular biosimulation—precise computer modelling that aids the study of the human body and how drugs work—can quickly assess billions of options to find the most promising medicines. Last summer the first drug designed end-to-end by ai entered phase-2 trials for treating idiopathic pulmonary fibrosis, a lung disease. Dozens of other ai-designed drugs are now entering trials.

‘Both the drug-discovery and trial pipelines will be supercharged as simulations incorporate the immensely richer data that AI makes possible. In all of history until 2022, science had determined the shapes of around 190,000 proteins. That year DeepMind’s AlphaFold 2 discovered over 200m, which have been released free of charge to researchers to help develop new treatments.

‘Much more laboratory research is needed to populate larger simulations accurately, but the roadmap is clear. Next, AI will simulate protein complexes, then organelles, cells, tissues, organs and—eventually—the whole body.

‘This will ultimately replace today’s clinical trials, which are expensive, risky, slow and statistically underpowered. . . .’

economist.com |TheEconomist

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We aren’t doing enough about the risk of bird flu—but we can—Tom Frieden (h/t Lynn Brown)

‘The United States’ response to H5N1—“bird flu”—has taken too long, showing how risky gaps in coordination and trust can be. With three cases reported in people in the United States and clusters in cattle herds from Michigan to Texas, Idaho to North Carolina, it’s clear that the virus is widespread among animals. To protect people, animals, and our economy and to restore trust in public health, we need to get this right.

‘We’ve seen H5N1 coming for more than 20 years. Although the challenge was smaller because of it size, Finland stopped H5N1 in animals before it spread to humans last summer. . . . Finland did three things particularly well; all are relevant to the U.S. response to the virus.

‘Rapid response. Within 24 hours of the first cases being reported on a mink farm, Finland confirmed that the animals tested positive for highly pathogenic avian influenza H5N1, which was known to be circulating among birds in Finland, just at the virus has been circulating among birds in the U.S. for the past two years. Human and animal health specialists worked together immediately to track infections, including testing at-risk workers on farms with infected animals. . . .

‘Trust. Farmers already had a high level of trust in the Finnish Food Authority after years of successful programs, and had launched a surveillance program that resulted in rapid notification of unusual symptoms among their animals. Farmers were immediately reimbursed for the value of animals that needed to be culled to stop disease spread, strengthening trust of the government in the farming community. This trust will no doubt help Finland’s next move: vaccinating frontline workers against H5N1. They are the first country to do so. . . .

‘Coordinated government response. Human health and agriculture officials in Finland coordinated closely, paving the way for a rapid, effective response. The joint response strengthened detection, collaboration of industry groups, and protection of workers from infection. Finland rapidly passed new legislation to ensure it had the authority to implement effective control measures. . . .

‘We have a lot to learn, and no time to lose. First, localities, states and national authorities must work with one another. This will require multiple federal agencies—including CDC, USDA, FDA—and their state counterparts to share information transparently and in real time with each other and with the public. Second, Congress needs to provide resources to prevent and respond to pandemic risks, including for systems, workforce, and infrastructure so we’re prepared to stop new events before they become epidemics. Third and perhaps most importantly, we must quickly build relationships with farm owners and workers by being responsive to their needs and addressing their questions and concerns.

‘If one country responds to H5N1 well, that’s not enough. Microbes know no borders. Every country—including the United States—needs an effective response. . . .’

cnn.com | @cnn | @DrTomFrieden

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Analyzing Africa: Everything under the sun—John McDermott

‘[E]xponential growth of solar power, caused by better and cheaper photovoltaic panels and batteries, augurs a future of abundant energy. This is a shift that will impact the whole world, but its effect could be most profound in Africa. More firms and consumers will get inexpensive, dependable electricity without having to rely on utilities or wait for their governments to expand grid infrastructure. In other words, solar can help parts of Africa make that figurative jump from the 19th to 21st century.

‘There are some signs of this already happening. In the rich world utilities are at the centre of the shift to solar. In Africa the revolution is decentralised; it is driven by firms and consumers buying power directly from solar developers. Around 65% of the capacity added in Africa over the past two years came via firms’ bespoke projects. Two-thirds of miners already have or are installing on-site renewable energy. More than 400m Africans use solar home systems. . . .’

+ Dawn of the solar age, The Economist

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Arresting headlines

Llama golf caddies drive tourism, attract ‘llama-razzi’—Axios

It’s time to ban intelligence operations from interfering in public health—Center for Global Development (almost, but sadly not, unbelievable news from Reuters, h/t Lynn Brown)

How scared should you be of bird flu?—New York Times (h/t Lynn Brown)

Denmark to impose world’s first carbon tax on agriculture, with each cow costing $100 per year—Green Queen

A deadly new strain of mpox is raising alarm: Health officials warn it could soon spread beyond the Democratic Republic of Congo—The Economist

Three months into bird flu outbreak in U.S. dairy cows, experts see deep-rooted problems in response—STAT News

The cow burb problem: 4.5-minute video: Methane is a greenhouse gas 25 times more potent than carbon dioxide. One of the biggest sources of methane: cow burps. But don't blame the cows! The methane is actually created by microbes in the cow gut. IGI researchers Ermias Kebreab and Matthias Hess at UC Davis and collaborators at UC Berkeley are working to develop new tools to block the microbes from creating methane in the first place, sparing the Earth—and the cow—from the effects of the gas—Innovative Genomics Institute (h/t Helga Recke)

Transforming African food systems from the ground up: CGIAR’s regional partners and initiatives are ensuring that local agrifood innovations are truly local and “fit for purpose”—IPS

Nyando “climate-smart” villages in Kenya are using a mix of technologies to boost farmers’ ability to adapt to climate change, manage risks and build resilience (photo credit: S. Kilungu/CCAFS).