March 29, 2010
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.