Helping to establish environmentally benign livestock systems - all views are my own

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It’s time to stop comparing meat emissions to flying

By Frank Mitloehner

Millions of people grapple with the effect their lifestyle choices have on climate change, often leading them to draw comparisons between the greenhouse gas (GHG) emissions of their activities. But the discussion around emissions is full of nuances, and while we often search for easy analogies to paint a full picture of human-related climate impacts, they can create more confusion than clarity.

Case in point: I’ve recently come across several articles (here and here) comparing beef emissions with aviation emissions. They’re disappointing on many fronts. For starters, whenever we say a hamburger dumps more greenhouse gases (GHGs) in the atmosphere than a trip on an airplane, we’re reinforcing a misunderstanding of the true GHG emissions of aviation. What’s more, we do it in a way that’s colorful, memorable and easy to latch on to.

I can appreciate how having a sound bite is tempting and even useful like the recent Bloomberg assertion “… that the humble hamburger is a bigger contributor to the warming of the planet than the jumbo jet,” for example. The problem is, it’s not as simple as all that. Animal agriculture’s impact is overstated when speaking to an American audience, and aviation’s effect is understated when speaking to any audience.

U.S. livestock farmers have – and continue to – reduce GHGs

Globally, animal agriculture accounts for 14.5 percent of GHG emissions, the number that tends to be used to support the claim that eating meat is a bigger planetary enemy than the combustion of the fossil fuels used in aviation. But in the United States, isn’t it more helpful to look at U.S. animal agriculture statistics, especially when they’re vastly different from the global picture?

Here in the U.S., animal agriculture makes up a far smaller percentage of total GHG emissions than worldwide: 3.9 percent, according to the U.S. Environmental Protection Agency (EPA). Granted, the lower U.S. percentage is due in some part to the fact that the United States is highly industrialized and wealthy, and we are major users of energy, fossil fuels and transportation. So as those percentages swell, animal agriculture takes up a smaller piece of the pie.

Even so, our farmers are the most efficient in the world. Case in point: In Mexico, it takes up to five cows to produce the same amount of milk as one U.S. cow, and in India, it takes up to 20. These statistics point to the United States having the lowest GHG emissions per unit of milk of any country in the world. It’s a similar story for other ruminant and non-ruminant animals that produce meat in the United States. In fact, emissions from all U.S. livestock species are much lower than those in Brazil, China, India and countries in the European Union, among others.

Americans fly more – much more – than people in any other country

Consistent with using a global number for animal agriculture is the tendency to do the same thing with the GHG emissions of air travel, and that likewise distorts the picture for the United States. Whereas the global animal agriculture figure is inflated for a U.S. audience, the global aviation figure downplays the role air travel plays in the United States’ GHG emissions. 

That’s because Americans fly much more than people in other countries, including China, the United Kingdom, Germany and Japan, other top consumers of air travel. According to Bureau of Transportation Statistics, there were 1 billion passengers on U.S. airlines and foreign airlines serving the U.S. in 2019, a record and yet another year-over-year increase since the global recession of 2008-2009.

Aviation is two to three times more damaging to the environment than is often reported 

In our hamburger-airplane example, aviation is assigned a GHG emissions number of 2 percent, giving most readers reason to have a clear conscience when boarding a plane. But that number doesn’t capture a plane’s full emissions footprint.

A 2 percent “GHG emissions” figure for aviation accounts only for the amount of carbon dioxide (CO2) air travels puts in the atmosphere. It ignores, the other GHGs that come from planes (for example, nitrous gases, water vapor, soot, particles and sulphates).

Emissions from flying

Graphic credit:

In addition, the 2 percent number is a tailpipe assessment, meaning what is being measured are the direct CO2 emissions from the jet fuel that is combusted in the planes’ turbines. The figure fails to consider things such as the manufacture of materials for parts used in the aircraft, the transportation of materials and parts to factories where planes are made, wear and tear on roads and runways, and many more.

Life-cycle assessments and tailpipe emissions are GHGs’ apples and oranges

When we look at our metaphorical burger, we’re taking into account pretty much every GHG that is emitted by the activities and processes required to get the proverbial burger on a dinner table. Called a life-cycle assessment (LCA), it provides a more accurate and total picture of GHG emissions than does a direct (tailpipe) assessment.

In the same example, air travel gets a huge break by being subjected only to a measurement of its (direct (i.e. tailpipe) emissions. To make a fair comparison, the same system of quantification must be used for both the burger and the airplane ride, and ideally, a life-cycle assessment would provide the figures. The thing is, we don’t have life-cycle assessment numbers for planes, or other parts of the transportation sector.

Direct emissions vs. life-cycle emissions

Graphic credit: Thompson Reuters Foundation News.

Methane is a short-lived GHG; carbon dioxide might be forever 

When we talk about the GHG emissions of livestock or the carbon footprint of meat, methane is often at the heart of the matter. Ruminant animals such as cows emit methane. As far as global warming potential, methane is a powerful GHG, with about 28 times the warming potential of carbon dioxide over a period of 100 years. 

But methane doesn’t hang around for a century; it’s a short-lived GHG. In about a decade’s time, it’s converted to water vapor and carbon dioxide, which is part of the cycle whereby plants take CO2 out of the atmosphere and convert it into feed via photosynthesis. Animals eat the non-human edible vegetation and upcycle it to meat and dairy products that provide efficient sources of protein and other essential nutrients to humans. It’s a cyclical process, also referred to as the biogenic carbon cycle, that’s been around as long as life itself.

Given the advances American farmers have made in animal agriculture, today we are producing as much food as we did 50 years ago from cattle herds that are far smaller. All told, the U.S. herd is contributing less methane to the environment as a result.

On the other hand, our voracious appetite for fossil fuels has resulted in an enormous glut of carbon dioxide in the atmosphere. According to the EPA’s GHG inventory, CO2 accounted for 82 percent of GHGs in 2017, with industry, transportation and electricity contributing nearly 80 percent of the total. It’s so much more emissions than oceans, rainforests and plants can absorb, by conservative accounts, it will hang over the planet for a thousand years. Realistically, it could be forever.

The comparison between livestock and aviation has so many nuances, the chances for getting it wrong are high. And when we do get it wrong, we diminish the impact of major polluters. Can we afford to take such a gamble when the information might become the basis for public policy decisions we so desperately need?

As the saying goes, when pigs fly.

Frank Mitloehner is a Professor and Air Quality Specialist. Director, CLEAR Center. Department of Animal Science, University of California, Davis. You can follow him on Twitter at @GHGGuru.

Carbon Emissions from Amazon Fires Pale in Comparison to Burning of our Fossil Forests

While the world is focusing on the burning of the immense above-ground Amazon forest, no one is mourning the loss of the (fossilized) forests that lie below the surface of the earth. The ones we are churning through at an unprecedented rate are our ancient forests, commonly referred to as “fossil fuels”, with enormous impact on greenhouse gas emissions.


Fossil fuels are plants and animals that inhabited the Earth hundreds of millions of years ago, and that are now unleashed, promising their minions untold comforts and riches. But the gifts come at a price far dearer than anyone could have imagined. Once freed from the “vasty deep,” they wreak havoc on the planet and the very people who set them free, calling into question their ability to survive the invasion.


It sounds like a science fiction movie, but sadly, it’s rooted in fact. Our seemingly endless obsession with the burning of fossil fuels is doing more than any other human activity to add excess carbon dioxide (CO2) to our atmosphere. As a matter of fact, the use of fossil fuels accounts for almost 37 gigatons of the total 49 anthropogenic (human-caused) gigatons of greenhouse gases (GHG) entering our atmosphere each year. In other words, most of them.


The Amazon is big, but the behemoth lies below

As the fires in the Amazon continue to burn, it’s more important than ever to remember where the lion’s share of our CO2 is coming from. Many have warned that the potential demise of the world’s largest rainforest will mean a disastrous release (as far as global warming is concerned) of the carbon that is naturally stored in the plethora of plant life that lives there.


In addition, it would affect the short-term carbon cycle, whereby plants and animals (including us) exist in a wonderfully symbiotic relationship involving oxygen and CO2. We not only exist together; we exist because of each other, using each other’s nutrients to sustain life. As magical as the short-term carbon cycle is, however, it is woefully inadequate when it comes to making a dent in the glut of CO2 hanging in our atmosphere from fossil fuels.

It bears emphasizing that the Amazon wildfires are tragic for many reasons, including the fact that they are now acting as a smokescreen for the biggest burn of all. While the world is focusing on the demise of this immense above-ground forest, no one is mourning the loss of the ancient forests that live below the surface of the earth. The ones we call fossil fuels and which we are churning through at an unprecedented rate.


The world beneath us

Few have said it more colorfully than Peter Brannen in his recent article in The Atlantic:

“Underneath West Virginia and England are vast sleeping jungles, over 300 million years old, filled with centipedes the size of alligators and scorpions the size of dogs. Under West Texas is a tropical coral reef from a 260-million-year-old ocean, visited, in its day, by sharks with circular saw teeth. Under Saudi Arabia are whole seas of plankton that pulsed with the seasons and sunbathed under the waves in the age of dinosaurs,” he says. “This is what we are burning at Earth’s surface today. We’re not just burning down the Amazon. We’re burning down all the forests in Earth history that we can get our hands on.”

Simply put, fossil fuels are the plants and animals that avoided decay and instead, slowly but surely morphed into oil, gas coal and rock under extreme pressure and with the luxury of millions of years of being left alone.


They were once living things, which means they’re largely made up of carbon. When they’re brought to the surface of the Earth and burned, the carbon combines with other gases, with the major byproduct being CO2. After water vapor, CO2 is the most plentiful greenhouse gas in our atmosphere. As such, it serves as a ceiling that prevents the sun’s heat from dissipating into the atmosphere. A healthy amount makes our planet habitable. More than we need makes Earth too warm.


The story of climate change

Of the major greenhouse gases CO2, methane (CH4) and nitrous oxide (N2O), CO2 has the lowest potency (i.e. global warming potential per molecule). Yet, its life span is much longer. As the EPA points out, some of it is absorbed very quickly by the ocean, but “some will remain in the atmosphere for thousands of years ….”


It’s more than a story of climate change. It is THE story of climate change. In less than a century, we’ve churned through what many believe to be half of the fossil fuels that reside in the Earth’s crust, effectively turning the natural carbon cycle into a one-way street that dead-ends in our atmosphere. Consider that our greenhouse gases consist of more than 80 percent CO2.


And yet, we continue to hear that we have to take personal action to affect climate change. There’s an oft-heard battle cry that if we give up meat, we’ll save our planet. That’s far from the truth. In reality, in the US, 80 percent of all GHG stem from fossil fuel using industries. In contrast, all of animal agriculture contributes to 3.9 percent (all of agriculture is 9 percent) of GHG emissions and overall, agriculture and forestry combined, reduce (i.e. sequester) more GHG than they emit.


To be clear, I’m in no way suggesting that livestock and other factors don’t contribute to greenhouse gases. They clearly do. In the case of animals, some give off methane, which has 28 times the global warming potential of CO2. Even so, methane behaves very differently than long lived climate pollutants such as CO2, and thus, we have less to fear than some would have us believe. (Stay tuned for a future blog post about the difference between a short-lived gas like methane and CO2.)


Is anyone listening?

Indeed, there is a long list of activities that are turning up the heat on our plant. The problem I see is that some of them – meat consumption and deforestation, for example – while not innocent bystanders, are often put forth as scapegoats. The major problem by far – the 800-pound gorilla, as it were – is the burning of fossil fuels. Michael Mann and Jonathan Brockopp recently said as much in their op-ed that appeared in USA Today, America’s most widely circulated newspaper.


I wonder if anyone heard them. I wonder if anyone wants to.


It seems as if we will do whatever we can to avoid pointing a finger at our insatiable appetite for fossil fuels. And until we do, we’ll never be able to see the forest for the trees.

Use your head – the Amazon isn’t our lungs

Over the past three weeks, there’s been an abundance of news reports and opinion pieces related to the fires in the Amazon rainforest. It’s not undeserved. At more than 2 million square miles, the tropical rainforest is the world’s largest, not to mention a treasure trove of flora, fauna and landforms. Nowhere on Earth is there more biodiversity. Its beauty alone commands awe and respect.


Yes, it’s not surprising that the world should be concerned with the tens of thousands of wildfires that have hit this planetary wonder. What’s confounding is the amount of misguided rhetoric that has sprung forth, not the least of which is that U.S. beef consumption is to blame for the blazes. (For the record, it’s not. Only 0.5% of beef consumed in the United States comes from Brazil – where the largest portion of the rainforest is located – and soy produced there is not fed to U.S. beef cattle.)


Make no mistake – I’m not minimizing the wildfires. Neither am I being cavalier about the myriad of issues behind them or the effects they could or will have in the near and long term. The environment is an intricately composed symphony. When one instrument is out of tune or a musician misses a note, the performance is the lesser for it. Maybe not even worth the price of admission. In environmental terms, that means a lot of cacophony in the form of extinction, pollution, climate change and more.


Like you, I’ve been reading and listening intently these past few weeks. Elements of some conversations have intrigued me; others have caused me to shake my head. Perhaps the most alarming of all claims is that the Amazon is the Earth’s lungs.


The idea here is that such a vast reserve of plant life is responsible for taking a large amount of carbon dioxide out of the atmosphere and giving us much-needed oxygen through a process that harnesses solar power to perform photosynthesis. Lose the rainforest and we miss out on all that Obeing “exhaled” by plant life. Without oxygen, we struggle to breathe, and we die.


French President Emanuel Macron even went on record to say we’d be without 20 percent of our oxygen if the Amazon rainforest burned to the ground. He isn’t alone. Others are issuing similar warnings.


There’s nothing pleasant about the thought of gasping for air, but don’t let it keep you up at night. The Atlantic recently painted a very different picture, which should make us all breathe easier, at least when it comes to our oxygen supply. Kudos to Peter Brannen for tapping into the work of Shanan Peters, a geologist from the University of Wisconsin at Madison, to debunk the lungs myth.


Professor Peters points out that oxygen has been accumulating in our atmosphere for billions of years, the byproduct not of photosynthesis, but of wasted plants and animals that exist now as fossil fuels. In fact, we have a glut of the stuff that we humans need to live; our atmosphere is 20.9 percent oxygen. If the Amazon rainforest were to disappear, that number would move downward – by a mere .5 percent, Professor Peters said. In a nutshell, “Humans could burn every living thing on the planet and still not dent its oxygen supply.”


As an important aside, our store of oxygen doesn’t mean we’re in the clear. Particles and smog-forming gases that a fire produces are irritants; toxic even. Think of an ordinary housefire where inhabitants suffer smoke inhalation, but on a massive scale.


As far as oxygen goes, humans and plants have been in lockstep since the first person walked the Earth, both players in  a cycle whereby plants are able to absorb carbon and convert it to food that nourishes us – or if it can’t be digested by us – nourishes animals that we can digest. The oxygen that’s put back in the atmosphere during photosynthesis is a bonus, but we’d be fine without it. Incidentally, most of it (50 to 85 percent) comes courtesy of phytoplankton in Earth’s oceans, not vegetation in the Amazon rainforest. The microscopic algae serve as the first link in a complex and vast aquatic food chain.


We’re not in danger of running out of oxygen anytime soon, so we can relax about that, even if we can’t always sit back and take a cleansing breath.







Guardian and OPP ink deal to pen stories

It’s a frightening prospect to think any person or entity with significant funds could buy editorial time or space to promote a specific ideology, but that’s what’s going on between the Guardian and the Open Philanthropy Project (OPP).

In 2017, the daily U.K.-based newspaper sought and received a grant from OPP to regularly print editorial content in support of OPP’s well-established animal rights agenda. OPP is paying the Guardian $886,600 (USD) to publish a series titled “Animals farmed.” It consists of a steady stream of articles that paint animal agriculture as inhumane, unhealthy and dangerous to the environment.

Before going any further, let me be clear about something. In this day and age, newspapers are under increasing pressure to find sources of revenue to replace subscriptions and lost advertising dollars, for example. The Guardian has been transparent in its solicitation and receipt of funds from OPP and even includes a statement of funding and the OPP logo on all stories that are written under the terms of the grant. I don’t admire the Guardian’s selling of its editorial space, but at least it’s not keeping it a secret. Although honesty is the best policy, the Guardian’s actions still fall short of my view of what journalism should be about. I’m sure others would agree.

According to the National Union of Journalists’ code of conduct, which “has set out the main principles of UK and Irish journalism since 1936,” a journalist “at all times upholds and defends the principle of media freedom, the right of freedom of expression and the right of the public to be informed.” In the book “The Elements of Journalism,” Bill Kovach and Tom Rosential lay out 10 principles of good journalism. Journalism’s first obligation is to the truth and its first loyalty is to citizens, they say. Journalists must remain independent of those they cover and “must serve as an independent monitor of power.” Meanwhile, “members of the Society of Professional Journalists ascribe to the ideal that public enlightenment is the forerunner of justice and the foundation of democracy. Ethical journalism strives to ensure the free exchange of information that is accurate, fair and thorough.” Without these principles that guide so many journalists throughout the world, what we have is propaganda. Plain and simple.

The Guardian espouses “open, independent journalism,” or so it says on its website. “Our mission is to keep independent journalism accessible to everyone, regardless of where they live or what they can afford. Funding from our readers safeguards our editorial independence. It also powers our work and maintains this openness. It means more people, across the world, can access accurate information with integrity at its heart.”

What I have a problem with is this: OPP is no ordinary reader. It’s funded by Dustin Moskowitz, one of the founders of Facebook. It has an unapologetic focus on farm-animal welfare – which it has every right to have, by the way – that is led by Lewis Bollard, a former leader at the Humane Society of the United States. It recently handed over $4 million in support of Prop 12 in California. Oh, and it is an investor in Impossible Foods, the maker of the Impossible Burger. The point is, its resources are significant, and it stands to gain financially and otherwise from the furthering of its anti-livestock agenda.

I wonder how many of the Guardian’s readers throughout the world truly understand “Animals farmed” is advertorial copy designed to win them over to OPP’s view of animal agriculture.

I’ll debate the OPP and its beliefs until the cows come home. I’ll answer the call of any journalist who follows a published code of ethics. (And most of them do, thankfully.) I’m not afraid of anyone who disagrees with me. The important thing is to keep talking and listening to each other to broaden our minds and come up with answers to problems and issues that affect every person on this planet, most of all those who can’t afford to pay to play as the OPP can.

My beef has long been with people and entities that use their power and resources to unduly influence others.

Is it possible, thanks to the Guardian’s up-for-sale editorial policy, that we have something more nefarious to fear?

The “Cowspiracy” Conspiracy: Anti-Animal Agriculture Movie Producers Change Their Story

Something remarkable happened recently: The producers of the movie “Cowspiracy”, a documentary produced by Leonardo DiCaprio, which makes wildly inaccurate claims about the role of animal agriculture in climate change, publicly backed away from the main tenet of the movie and what may well be the biggest gee-whiz stat in the 2014 documentary.


In an effort to present animal agriculture as the most fearful threat to our environment, the World Watch Institute and producers Kip Andersen and Keegan Kuhn cherry-picked an inflated number from a single, flawed source. Armed with the faulty data, they made the claim that animal agriculture is responsible for a staggering 51 percent of greenhouse gas (GHG) emissions worldwide, more than any other source, including transportation.

I am afraid “someone whipped data until they confessed”, which does not make them right after all.


As a professor and air quality specialist at the University of California – Davis, and the former chairman of LEAP, a global United Nations Food and Agriculture Organization (FAO) partnership project to benchmark the environmental footprint of livestock production, I was dismayed by “Cowspiracy’s” claim. Not just has LEAP commented on Conspiracy earlier, I’ve been working tirelessly to set the record straight about animal agriculture in general and “Cowspiracy” in particular. My efforts are not simply for the satisfaction of being right; but rather, to help us focus on real, scientific-based facts that will lead to working toward a common, effective, well-informed solution to mitigate the serious problem of global warming.


I’m not alone, either. Anne Mottet and Henning Steinfeld, leading FAO livestock staff, recently published an article on the dangers of oversimplifying GHGs from livestock. Although they submit there is no life cycle estimate for global transportation, in the United States alone, “the life cycle of passenger transport would be about 1.5 times higher than the operational ones.”


These days, Andersen and Keegan are much closer to the truth, having tweeted and posted that 18 percent of GHGs is from global animal agriculture on their website,

Incidentally, the 18 percent figure is still not accurate, having come from the FAO study “Livestock’s Long Shadow,” which has since been revised by its authors to 14.5 percent (FAO “Tackling Climate Through Livestock,”), but at least it is far less misleading than 51 percent. Perhaps reluctant to dial back the statistic, they seemingly couldn’t resist stating that even at 18 percent, it is more than “the combined exhaust of all transportation,” using a life cycle (direct and indirect) assessment for animals and a mere tailpipe emission (direct only) for transportation, an assertion Mottet and Steinfeld debunked in their article noted above.

Even more disturbing is that the overly inflated 51 percent number is still being espoused, even in the infographic still on and elsewhere on the internet where people go for information. No wonder everyone is confused.


One of the latest to pick up on the cringe-worthy 51 percent is Beyond Meat, which showed the stat on its home page as recently as September 2018, seemingly to sway more people to purchase the company’s plant-based products that mimic meat.

Now, I’m not here to tell you what to buy or what to eat by any means, nor do I worry that others are happy to do one or both. What I take exception with is using false data for any purpose.


With that in mind, I fear that “Cowspiracy” is another example in a long list of vegan spokespeople who are more interested in furthering their agenda than in telling the truth. Given the size of the audience that “Cowspiracy” has played to on Netflix, I want to offer the facts to one that is just as large, if not more so. I’m hoping you agree.


Finally, when researching about this blog, I noticed that the same Leonardo DiCaprio who produced this film Cowspiracy, is also significant investor in Beyond Meat, the plant based company using the same flawed numbers. Some would say a logical consequence; other would call it a conflict of interest. Regardless, no reason why the one cannot learn from the other.


At the risk of sounding naïve, I believe people generally want to do the right thing. The problem is, we continue to bombard them with directives based on falsehoods. Whether intentionally or through misinformation, the outcome is the same. It keeps us from getting on the same page to work on a global solution to the problem of climate change.


-Frank Mitloehner (aka @GHGGuru)


Beef with meat tax and cancer claims

It seems we live in a time when people simply don’t know what to eat. Many of us want to do what’s right for our bodies and our planet, but we’re bombarded with conflicting messages or information that is just plain false.


On Nov. 7, 2018, news giant CNN, which touts itself as “the most trusted name in news,” reported a global meat tax could save 220,000 lives and cut health care bills by $41 billion each year. CNN’s report is based on a recent study from Oxford University.


“The numbers are based on evidence that links meat consumption to increased risk of heart disease, cancer, stroke and diabetes. Three years ago, the World Health Organization declared red meat such as beef, lamb and pork to be carcinogenic when eaten in processed forms, including sausages, bacon and beef jerky,” it said.


My life’s work centers on animal agriculture and air quality, and the goal of feeding a world population that will reach 10 billion in about three decade’s time. Information such as that put forth by CNN concerns me because meat’s connection to cancer has never been substantiated. Neither can one put the blame for heart disease, stroke and diabetes squarely on the shoulders of meat.


Peeling back the layers, today I want to take a half-step away from my day-to-day work to focus on the myth (perpetuated by many, including CNN yesterday) that eating meat, especially red meat and processed meat, can lead to cancer. My reason? We need – and will continue to need – animal protein to sustain human life. Without it, we simply can’t get enough essential nutrients for our global population. Buying into an unsubstantiated claim that red meat and processed meat lead to colorectal cancers (CRC) takes our eyes off the ball with nothing to be gained in return.


Partly to blame for the misconception is a 2015 study from the International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO). The report tried to link meat with certain types of cancer, primarily CRC. This year, IARC released the full scientific basis of its finding, confirming just how weak the evidence linking meat and CRC is.


For instance, IARC claimed that 800 studies were used in its review, but in reality, nearly all were eliminated. Only 14 studies investigating red meat and 18 studies investigating processed meat were considered, and evidence showed deeply conflicting findings, not clear and convincing evidence. In the end, one has to wonder why it took IARC more than two years to present the evidence used to arrive at its 2015 conclusion, especially if that evidence was so bulletproof.

The message from IARC has been so misleading and has caused such confusion that its parent organization, WHO, came forward several years ago to deflate IARC’s claim and reassure the public that meat should be consumed in moderation as part of a healthy, balanced diet.


In addition, the U.S. National Cancer Institute (NCI) states in relation to colon cancer, “There is no reliable evidence that a diet started in adulthood that is low in fat and meat and high in fiber, fruits, and vegetables reduces the risk of CRC by a clinically important degree.” In fact, the NCI takes it one step further, saying it’s “not clear” if diet affects the risk of colon cancer at all.


Professors Gordon Guyatt and Benjamin Djulbegovic, two leaders in evidence-based medicine, recently pointed out the minimal relative risk of meat leading to CRC: 1.17. Compare that to smoking, which makes one’s chances of developing lung cancer nine to 25 times greater, or to the fact that when IARC tested 1,000 substances for cancer-causing properties, only one – a chemical found in yoga pants – was found not to cause cancer. Further muddying the waters is the fact that it’s not possible to test meat’s connection to cancer in a vacuum. Other factors can’t be isolated easily, if at all. To that point, Professors Guyatt and Djulbegovic are correct in pointing out that vegetarians tend to be more alert to good health in general. They are more likely to exercise and refrain from smoking, at the same time coming from a higher-than-normal socio-economic class, some or all of which could have a bearing on the development of cancer.

If only cancer could be linked to a single cause. Who wouldn’t wish for that? However, cancer is a very complex disease that simply can’t be traced to one factor, let alone one food source. Genetics, physical activity levels and lifestyle habits (e.g., tobacco and alcohol use) play a role.


Putting a so-called “sin tax” on meat would only make it more difficult for consumers to access a food product that is vitally important to human health and survival now and in the future. Adding insult to injury is the fact that its upside (or promise) is negligible at best. There is no credible, science-based evidence to prove it would reduce cancer.


-Frank Mitloehner (@GHGGuru)



When fewer animals = more protein

When fewer animals = more protein

It’s a proverbial win-win situation. Find a way to get more protein from fewer animals. It would make us better positioned to feed a global population that will total 10 billion by 2050, at the same time avoiding or at least limiting the deforestation of lands to create farmland and reducing greenhouse gas emissions.

It’s not a dream. It’s an achievable goal, especially if we can apply the knowledge and expertise of developed countries to those that are developing. The latter are currently producing less protein from more animals. In addition, they stand to experience the greatest population growth in the next decades, making the need for efficiency critical to sustaining the planet’s life and its environment.

History gives us reason to be optimistic. Great progress has already been made to improve the environmental efficiency of cattle production in the developed world. According to the USDA, the total number of beef cattle in the U.S. peaked in 1975 with a population of 132 million head. Since then, the population has steadily declined, with the 2017 population at approximately 94 million. However, the amount of beef between 1975 and today has remained stable.

The record cattle population of 1975 produced 24 million tons of beef, while the 2017 population, with 38 million fewer head, produced 26 million tons of beef (USDA, 2016). This sustained trend means the beef industry has been able to produce much more beef per animal unit, thereby decreasing the amount of feed, animal waste and enteric emissions needed to produce each product of beef by diluting out animal maintenance costs (reducing the proportion of feedstuffs required to keep the animal alive relative to the total feedstuffs consumed).

We’ve achieved the same results with dairy production. For example, today one California cow produces the same amount of milk as two of her peers in Mexico and nine of her peers in India. Capper et. al. pointed out that compared to 1944, the 2007 U.S. dairy industry reduced its greenhouse gas emissions per unit of milk by 63%. This reduction was achieved through improved nutrition, management, genetics, etc., born through scientific research that has led to dramatic improvements in milk production per cow. It’s worth pointing out that even more could be achieved in the United States and other developed nations by advancing genetics, nutrition, animal health, etc., to dilute maintenance costs further to lower the life cycle GHGs per unit of beef or dairy product.

Intensification of livestock production provides large opportunities for climate change mitigation and can reduce deforestation, thus becoming a long-term solution to more sustainable livestock production. It also gives us the most efficient way possible of meeting an unprecedented need for protein as part of the 2050 challenge.

-Frank Mitloehner (@GHGGuru)

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