Mixing Diet Advice and Climate Advocacy?

Projecting Personal Values Can Backfire


There are many reasons why we should think carefully about our diets and the balance of meat we consume, climate change being among them. But research suggests that when celebrities like James Cameron make headlines by advocating veganism as a solution to climate change, these well intentioned statements may backfire with broader audiences.

April 21, 2014 | Matthew Nisbet

I very much enjoyed the first episode of the new Showtime series Years of Living Dangerously and I have been rooting for the series' success. In part, the cable network production directly speaks to my own outlook as someone who is deeply concerned by climate change and who leans more liberal than centrist. But as a social scientist studying the climate debate for the past decade, I also believe that Ted Nordhaus' and Michael Shellenberger's recent New York Times op-ed and subsequent essays have raised a number of questions that are well worth considering, especially by fans of the series.

I’ve highlighted those questions at Google + and plan to return to them after I have a chance to reflect on the rest of the Living Dangerously episodes.

Yet in the meantime, I wanted to flag a recent instance where in promoting the series, executive producer James Cameron may be conveying the type of cultural cues that speak to only a narrow slice of the public, while potentially turning off broader segments of Americans who are otherwise inclined to be concerned about climate change

In an interview with the viral web site Reddit, Cameron was asked the best thing that an individual can do to fight climate change. “Stop eating animals,” was his reply. As he elaborated:

This may surprise you, because it surprised me when I found out, but the single biggest thing that an individual can do to combat climate change is to stop eating animals…Because of the huge, huge carbon footprint of animal agriculture. I was shocked to find out that animal agriculture directly or indirectly accounts for 14.5% of all greenhouse gas emissions, compared to all transportation – every ship, car, truck, plane on the planet only accounts for 13%. Less than animal agriculture. So most people think that buying a Prius is the answer, and it’s certainly not wrong, but it’s not the biggest agent of climate change.

In past comments, Cameron says he was converted to veganism by the documentary Forks Over Knives and he has argued that you can’t be an environmentalist if you don’t eat a plant-based diet.

I view Cameron's comments as sincere and well-intentioned. In part, they are as Roger Pielke Jr has aptly argued an example of climate change being "a bit like a policy inkblot on which people map onto the issue their hopes and values associated with their vision for what a better world would look like."

All of us working on climate change are likely guilty of this to a degree, but there is a bigger perceptual problem with Cameron’s advocacy of veganism in promoting the Showtime series, one that could potentially backfire with intended audiences.

In a 2010 co-authored study with Ed Maibach and colleagues our interview results showed that broad segments of Americans –ranging from the Alarmed to the Dismissive in their views about climate change – found information about the problem useful and compelling when it was framed in terms of mitigation related actions that offered specific benefits to public health.

But the one argument that members of all segments reacted to relatively negatively was the suggestion that they change their eating habits from meat to more fruits and vegetables. *As far as I am aware, our study is the only to date that directly evaluates how different publics respond to advice to shift their diets in the face of climate change, indicating that we need to do more research on this line of argumentation before deploying prominently in public engagement campaigns.

Until then, when celebrities like James Cameron make headlines by advocating their own personal embrace of veganism, they would be wise to reflect on how such recommendations are likely to be received and re-interpreted by the public.

Below is the key section from the results section of our study and you can read the full open-access version here. *We designed the study believing that the diet advice along with the other health co-benefits highlighted would be persuasive. In the figures linked below, you can see that although the other emphasized health co-benefits resulted in a strong positive response and train of thought with people finding the information useful and compelling, the advice on diet (sentence labeled B4) disrupted this positive train of thought, with reactions moving in the negative direction among all groups, but most prominently among those on the more doubtful part of the climate change perception continuum.

Also worthy of note, as Figures 4 and 5 indicate, is that all six segments reacted positively to the following statements focusing on specific mitigation-related policy actions that lead to human health benefits:

"Taking actions to limit global warming - by making our energy sources cleaner and our cars and appliances more efficient, by making our cities and towns friendlier to trains, buses, and bikers and walkers, and by improving the quality and safety of our food - will improve the health of almost every American."

"Cleaner energy sources and more efficient use of energy will lead to healthier air for children and adults to breathe."

"Improving the design of our cities and towns in ways that make it easier to get around on foot, by bike and on mass transit will reduce the number of cars and help people become more physically active, lose weight."

Conversely, respondents in all segments responded less positively to the statement:

"Increasing our consumption of fruits and vegetables, and reducing our intake of meat - especially beef - will help people maintain a healthy weight, will help prevent heart disease and cancer, and will play an important role in limiting global warming."

* Post updated with more details on study design and results in response to query about diet advice "backfiring" or resulting in more negative/less positive reactions to an argument intended to be persuasive.


Maibach, E., Nisbet, M.C. et al. (2010). Reframing Climate Change as a Public Health Issue: An Exploratory Study of Public Reactions. BMC Public Health 10: 299.


  • The diet-related messages probably also trigger latent, negative stereotypes about environmentalists: that they’re sanctimonious and judgmental, they’re out to control or subvert your way of life that in many ways defines who you are, etc. I’m a liberal and I recoiled at this image…I can only imagine how it goes down with people to the right of me.

    By Luis Hestres on 2014 04 21

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  • Hi Luis,
    Thanks for this comment. There was a recent study on negative stereotypes about environmentalists that is of relevance. News summary: http://www.salon.com/2013/09/26/study_everyone_hates_environmentalists_and_feminists_partner/
    Actual study: http://onlinelibrary.wiley.com/doi/10.1002/ejsp.1983/abstract

    By Matthew Nisbet on 2014 04 21

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    • V. interesting. You could call this the Activism Paradox: to attract like-minded and committed people you need to play to those stereotypes to some extent, but that also repels others who might otherwise be sympathetic. It’s so important to pair the right message with the right messenger, which is easy enough to do through narrower channels like face-to-face or social media, but not so much through mass media. The real danger is when a stereotypical activist becomes the “face” of an issue through mass media.

      By Luis Hestres on 2014 04 22

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  • Preaching Veganism will mostly fall on deaf ears. People around the world are choosing to eat more meat as they rise out of poverty. If James Cameron wants people to convert he is more likely to succeed with tasty and economic synthetic meats.

    By David Owen on 2014 04 21

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  • Thanks again Luis for this follow up. Readers may be interested to read Luis Hestres’ recently published study on the organizing strategies of 350.org. It’s a fascinating analysis and a line a research I will focus on more in depth in coming months at The Public Square.

    By Matthew Nisbet on 2014 04 22

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  • I agree with your position here. This particular item, is causing much divisiveness locally, where dairy farming is a major component of the county economy.  We can’t work through mitigation efforts if farmers feel under complete attack.  See for example: http://whatcom.wsu.edu/ag/biogas.htm.  Washington State University’s Agricultural Extension Service has worked to help farmers develop and implement agricultural systems and practices that mitigate global climate change.  Whatcom County, in Northwest Washington State, just south of Vancouver BC, Canada, is not an area where global climate change is, or is predicted to be, very observable in local weather patterns. In personal conversations with WSU researchers, it is clear that advocating for changes that aid climate mitigation efforts needs to be done with sensitivity to farmer’s economic needs.  This aids in increasing acceptance of global climate change as a matter of concern.  In this case, “Storage and land applying animal manure contributes significant greenhouse gas (methane, carbon dioxide, oxides of nitrogen) to the environment. Converting animal manure to energy and useable byproducts can reduce greenhouse gasses, plus provide other beneficial effects. ”  The health of salmon runs and shellfish beds are also of concern locally, and field applied manure is also an issue in that regard.

    By Gaythia Weis on 2014 04 22

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