March 29, 2010

Unsupported Claims About Livestock and Climate Change in the Media

Center for a Livable Future

Center for a Livable Future

As a public health doctoral student, I have been taught the importance of communicating scientific information to the public, journalists, and policy makers in a careful manner, especially when dealing with complex issues.  Scientific research almost never provides clear answers, but as a scientist you should never make statements that overstep the conclusions of your work, even if it would make your life easier by simplifying the message you are trying to get across.  Describing questions that remain unanswered and limitations of studies is important.  While reading a news release last week regarding research on food animal production and greenhouse gas (GHG) emissions, I was suspicious that this “rule” was not being followed.

An air quality scientist at UC Davis, Professor Frank Mitloehner, has been in the press talking about implications of his research on livestock production and GHGs (here, here, and here).  He has been quoted as saying it is  “scientifically inaccurate” and a “distraction” to encourage a reduction in meat consumption as part of an effort to combat climate change.  Those are very strong statements, so I did a little digging to see if his research supports these claims.

Professor Mitloehner co-authored a report on this topic, Clearing the Air: Livestock’s Contribution to Climate Change, that was published last year, and on March 22nd he presented the findings at the American Chemical Society meeting in San Francisco.  The authors take aim at the 2006 UN report, Livestock’s Long Shadow, for overestimating global GHG contributions from livestock while underestimating transportation emissions.   A major conclusion of Livestock Long’s Shadow is that livestock production contributes 18% of global anthropogenic GHG emissions, more than transportation.  One of the report’s main flaws, according to Prof. Mitloehner and his colleagues, is more inclusive methods were used to calculate GHG emissions for livestock compared to transportation.  Lifecycle analysis, which is very comprehensive, was used to produce the livestock emission estimates whereas a simpler, and less inclusive, method was used for transportation.  For example, the livestock estimates included indirect sources such as deforestation and feed production, while the transportation estimate only included direct emissions from vehicles (emissions associated with drilling, processing, and distribution of fuel were not included).

From what I have read, this is a fair criticism of the report and I think it is a positive step that the UN is currently working on a new comparison that will be released by the end of the year.  If the conclusions shared with the press focused on the importance of producing more comparable estimates for global GHG emissions from different sectors, that would be logical.  The problem is that Professor Mitloehner states that reducing meat consumption will have no impact on GHG emissions or global warming.  I am not a climate scientist, but it is easy for me to understand that if meat production contributes significantly more GHGs than non-meat food production, then reducing meat production would result in less GHGs produced.  (Just as reduced meat production would result in less water, fuel, and land being used to produce food.)  The claims Prof. Mitloehner is making could only be supported by research that found no difference after comparing food production based on different levels of meat in the public’s diet to estimate the resulting GHG emissions.  His research makes no such comparison.  In addition, the author is quoted as saying that reduced meat production would result in more hunger in developing countries.  Hunger is not addressed in the “Clearing the Air” report and it is not an issue researched by any of the report’s three authors.  In fact, research has shown the opposite to be true.  Some experts suggest that reducing meat production and consumption is one way to feed a growing human population.

After seeing the unreasonable disconnect between the claims made in the press and the actual research conducted by Prof. Mitloehner and his colleagues, I was not surprised to learn that the research was funded by a $26,000 grant from Beef Checkoff (source).  The funding source for the research was not disclosed in the journal where the report was published (Advances in Agronomy) or any mainstream media stories I have seen.  Obviously, industrial food animal production organizations have every right to fund scientific research, but it is disingenuous for scientists they fund to make statements that are not supported by their research in an effort to turn consumers and policy makers away from reducing meat consumption to combat climate change.  Unfortunately, the statements that have been in the media over the past week have only served to further confuse the issue and misinform the public.  This is an example of scientific integrity gone awry, and it illustrates the importance of an informed public and vigilant press that demand research results be communicated in a forthright, transparent manner.

–Jillian Fry


  1. I think this is a very good review for the manuscript. I share some of your thoughs and I don´t totally agree with Dr. Mitloehner´s views.

    I am not an author of the manuscript. I just know the work because I was sitting many times next to Dr. Pitesky while he was writing parts of the manuscript. Both of us are veterinarians and I have a PhD in animal production and so I got interested in his work. We were in Davis together taking the MPVM (vets equivalent to MPH). During the MPVM they insist very much in the importance of communicating scientific information in a good ethic manner, an I always felt that Dr. Pitesky is a great example good ethic communication. Probably, any bias in the manuscript could probably be more due to unintentioned errors than to an intention to favor beef industry, even when they are paying.

    Going back to the manuscript, I truly think current animal production needs a deep change and I think Dr. Pitesky shares this comment to, at least, 50%. What the manuscript says about the consequences of eating less meat is probably not true. You are right. It is also true that Long´s shadow report has very serious flaws that could be understood as intentioned at some point. I prefer to think that who wrote the report just lacked some technical knowledge at some point. Perhaps including Dr. Mitloehner in the panel would be a good idea while discussing next report.

    Livestock, and specially cows, are being over attacked for their responsability in climate change. Beef production system needs a reform, no doubt. And eating less meat would be benefitial, no doubt. However it is probably more accurate to say that what we need to do is to eat less (not only meat but especially). Pointing only to meat only produces unfortunate reactions from some interests. A more incusive collaborative approach is needed.

    We should not underestimate the magic of ruminants. These are animals that are able to create protein from straw and nitrogen, and they are vital in many parts of the world. So it would be helpful not to demonize them.

    Finally, I would like to bring here some of the discussions we had with Dr. Pitesky while he was working on the manuscript. I think these examples will help to put in perspective the effect of Dr. Pitesky´s work in a low impact journal compared to other works. For example, both visited in separated ocassions the wonderful academy of science in San Francisco. You just need to approach the section when they compare different sources of CO2 and they recommend to eat organic over conventional food. We both were horrified because millions of people, mainly kids, are seeing that sentence a year. That affirmation is difficult to demonstrate and I would like to know the source of such a sentence. For sure it is not Dr. Mitloehner but it had been a good thing if they had talked to him about his opinion about that sentence.

    This is to long of a comment and so lets leave the rest of examples for another day.

    As I said at the begining this is really a very good review. Congrats!!!

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  3. Posted by Frank Mitloehner

    Hi Jilian,

    I did not write the press releases and feel that a lot of the recent reporting has been a line-up of catchy sound bites.

    I want to draw your attention to the Columbia Journalism Review article, which has done an outstanding job analyzing the issue at hand (

    The FAO’s Livestock’s Long Shadow report was very valuable in creating an awareness of the importance of environmental sustainability as it relates to global livestock production. I agree with large portions of the report but, as has been reported extensively, have pointed out a flaw in one of its main conclusions. One could say, this one main conclusion is just one aspect of an otherwise relevant report, but this is the one point of livestock vs transportation is what the global media have focused on. This key statement in LLS’s executive summary — “The Livestock sector is a major player, responsible for 18% of GHG emissions measured in CO2e. This is a higher share than transport.” — has been quoted extensively over the last few years by animal welfare and food activists, leading to Meatless Monday and other social policy initiatives. This statement has now lost its validity (see BBC report, which is regretted by many who advocate for meatless nutrition. That’s what happens when a social or political agenda tries to use science as its sword. Science evolves constantly, and that evolution in my field has been unfortunate at this time for these individuals. What I really regret is that of these individuals do not really argue the science but try to discredit the scientist instead (i.e. conflict of interest discussion – see paragraph at the bottom of this contribution). This common approach is disturbing and problematic because it could cause scientists to steer away from contentious issues.

    If we go along with the erroneous calculations, then we relax on the transportation in the developed world, which is not right (the other day I heard a host of a well known TV show stating that “If you drive a Prius and eat burgers, then that is the same as driving a Hummer” — a classical example of LLSs unintended consequences). We should not relax on any issue concerning our society’s mass consumption and what it takes to make these products available. My personal approach is to purchase to the greatest extent possible food that is produced locally and sustainably, and that includes meat and dairy products, which we purchase from producers at our local food co-op and farmer’s market. My scientific objective, however, is to find real solutions for society at large that support a reduction in greenhouse gases and other pollutants. I believe we contribute to this phenomenon in every sector of industrial production and society, and I also believe we have the obligation to go about the mitigation of our contributions through evidence-based techniques and technology.

    In my opinion, modern livestock agriculture has experienced a marked improvement of efficiencies, leading to significantly decreased numbers of animals to produce a given amount of product that satisfies society’s nutritional demands. LLS agrees and concluded that “intensification of livestock production provides large opportunities for climate change mitigation and can reduce greenhouse gas emissions from deforestation, thus becoming a long-term solution to a more sustainable livestock production”. I fully concur with this statement and feel intensification will move us closer to a solution to provide nutrients to a growing population while protecting our natural resources as best we can. Intensification includes the use of improved animal nutrition, adapted livestock breeds, better health care for animals and improved hygiene – basically a second green revolution in the development world to satisfy the populations growing nutritional demands while minimizing environmental impact.

    In summary, I am not saying that livestock agriculture should take its focus off on reducing their environmental impact–they should and can become more environmentally benign as should all other industries. However, recognition of each industry’s relative impact and their potential to improve their sustainability will help inform farmers and regulators how to effectively reduce GHG emissions, as climate change is one of the most serious issues facing humanity.

    Frank Mitloehner

    P.s. You point out that the funding was not disclosed. This is incorrect. A UC davis news release from December stated the following:
    Clearing the Air” is a synthesis of research by the UC Davis authors and many other institutions, including the U.N. Food and Agriculture Organization, U.S. Environmental Protection Agency, U.S. Department of Agriculture, California Environmental Protection Agency and the California Air Resources Board. Writing the synthesis was supported by a $26,000 research grant from the Beef Checkoff Program, which funds research and other activities, including promotion and consumer education, through fees on beef producers in the U.S.

    Since 2002, Mitloehner has received $5 million in research funding, with 5 percent of the total from agricultural commodities groups, such as beef producers.

  4. I raise pigs on pasture. I eat meat. I have a net negative carbon footprint – our land sucks up over 1,400 tons of carbon a year and all that good stuff. I am pissed about the Livestock’s Long Shadow report for the simple reason that it lumped me, a low fossil fuel user and pastured farmer, in with CAFO factory farms and feedlots. I’m not promoting a “Eat Meat Only Diet”. Unlike the vegan evangelists I don’t really care what people eat. That is their business.

    What would be a far better is study that looks at local food, pastured for the meat, low fossil fuel inputs for both meat and veggies. A good omnivore diet based on local resources. This varies greatly with where you are. Veganism is NOT practical in our northern climate. Veganism and even vegetarianism requires too much transportation. Meat is an excellent way of harvesting sunlight and storing it as high quality protein and lipids for our long winters. It is part of a good diet here.

    Small scale farmers can feed the world. We don’t need Big Ag. Stop promoting it. This can be done and on a scale that would feed the world. Far better to have 10,000,000 small farmers. That’s food security.

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