Abandoning humanity’s traditional dietary choices in favor of salads and soy protein is a construct lost of born-again veggie believers embrace. But a credentialed scientist? Please.

Yet another study has just been published linking the consumption of animal foods with the destruction of the planet through exacerbating climate change. While I understand the threat that continuing production of greenhouse gases (GHG) poses for the global (and local) ecosystems, I’m getting sick of reading studies that all conclude the same way (as this one does): “It is likely that reductions in meat consumption would lead to reductions in dietary GHG emissions.”

Commentary:  Pushing vegan fairy talesTitled, “Dietary greenhouse gas emissions of meat-eaters, fish-eaters, vegetarians and vegans in the UK,” the study, published in the journal Climate Change (June 2014), purports to make the case that switching to a vegan diet would have a significant impact in reducing levels of GHG emissions.

As is always the case, it has serious flaws.

For starters, the lead investigator, Peter Scarborough, a researcher at the University of Oxford’s British Heart Foundation Centre, is a card-carrying member of the British Vegan Society. Might there be a wee bit of bias in his report? Just maybe?

Scarborough is also a specialist in two other areas that don’t support arguments about his objectivity: A scheme he’s developing to apply additional taxes on food products based on (his) calculations of their impact on public health and a related proposal to incorporate the cost of GHGs into the retail price of food.

Be glad this guy doesn’t hold an important public office.

Second, from reading through his methodology, it’s apparent that Scarborough recruited participants to the study through advertisements in vegan magazines and on vegetarian websites. Veggies who signed up were then asked to recruit their friends and relatives, a process he euphemistically called “snowballing.”

Most people call it “skewed sampling.”

Not surprisingly, based on the way the participants were chosen, he ended up with 42,838 women and only 12,666 men, and 25,915 non-meat eaters, compared with 29,589 meat-eaters. No way is that sample even remotely representative of the general population, which matters because the analysis of the GHG emissions was based on the differences between Scarborough’s arbitrary categories of vegan, vegetarian, fish-eater and meat-eater.

Are we really to believe that holier-than-thou vegans and veggies reported exactly what they ate? Including snacks and treats and less-than-healthy indulgences? Even if you pretend that the biases inherent in any food diary recall project were somehow minimized for this study, I doubt that avowed vegans and vegetarians would be scrupulous about identifying everything they ate.

Inside the numbers

But the ultimate problem with this study — and many others like it — is that the actual GHG values assigned to various food products make no sense. Supposedly, the relative value of the CO2 equivalents produced for various foods were based on a “life cycle analysis” of production, processing, packaging, distribution, retailing — the impact of food waste was also considered part of the calculations.

That should provide accurate estimates of the total emissions related to various food products, from planting the seed, whether for food or feed, to final disposition of any waste materials.

So what are we to make of the following data, which show an estimated GHG emissions comparison among various foods (in kilograms of CO2 equivalent per kilogram of product)?

  • Sugar                 0.1
  • Oranges              0.6
  • Corn                   0.7
  • Milk                    1.8
  • Soybeans           1.8
  • Beer                   3.8
  • Poultry                5.4
  • Pork                   7.9
  • Coffee              10.1
  • Mutton              64.2
  • Beef                 68.8

Seriously? Keeping in mind that this is a UK study — and they don’t grow oranges in Great Britain — Scarborough wants us to believe that beef is 100 times worse as a source of GHG emissions than tropical citrus fruit? Yes, Britain imports a lot of beef, especially since its domestic industry was devastated by BSE and hoof-and-mouth disease epidemics.

But the country imports all of its oranges, which have to be irrigated, fertilized, picked, packed and shipped across at least one ocean. And most conservative estimates of shrink and spoilage in the produce category start at about 30 percent. Yet we’re supposed to swallow the idea that meat from cows living on grass — neither Britain nor Ireland, its principal beef supplier, have extensive feedlots — is exponentially worse than citrus fruit in terms of GHG emissions?

And sugar? Grown in cane fields that are burned every season to produce a highly refined product that also must be shipped across the Atlantic Ocean? And its CO2 equivalent in only one-sixth that of citrus fruit?

Not likely, guv’nah.

And what’s with mutton’s calculation being almost as high as beef? Nobody bothers to fatten sheep for slaughter. They’re not eating grain; they live their entire lives on pasture. I’m guessing that since Britain imports a lot of mutton from Australia, that GHG calculation is skewed because the products has to be packaged, frozen and shipped some 12,000 miles to its destination.

But what both policymakers and the public is left with, however, is a takeaway that demonizes red meat as a climate scourge, while it lionizes tropical fruit and other imported foods are being healthier and climate-friendlier.

What happened to eating local? If Britain’s “ideal” diet, one that’s supposed to halt climate change, consists of fruit, vegetables and grains — most of which have to be imported — not only is such a theory unsupported by reality but the impact of a dietary switch on that scale would devastate local economies wherever animal agriculture is practiced.

But hey, Peter Scarborough’s expertise is in figuring out ways to add taxes to food products, not in making sure people have a job so they might be able to afford those taxes.

The opinions expressed in this commentary are solely those of Dan Murphy, a veteran food-industry journalist and commentator.