The other day I encountered an interesting review of facts and suppositions on the question of how the human diet affects the environment. Interesting, because it challenges some of the generalities that tend to dominate the public conversation on the topic, for example, that consumption of vegetables invariably has a lower environmental impact than masticating meat.
The writer, Tamar Haspel, is quite persuasive in suggesting that it "ain't necessarily so." To cite just one example: Broccoli, if judged purely on the basis of the carbon impact of growing it (carbon emissions per pound), shows up as one of the lowest-impact foods. But food equivalencies depend upon calories -- meaning that if you want to replace a kilo of beef in your diet with broccoli, you have to eat (and therefore grow) 6.7 kilos of it to obtain the same caloric value. That 6.7 kilos, of course, has a much greater carbon footprint than just 1 kilo.
The position of tomatoes in the hierarchy changes even more drastically when calories are factored in. So lamb is still the most "evil" of the 20 foods ranked here, but tomatoes move from an angelic position 19 (i.e. near-lowest environmental impact) to a "bad-boy" ranking of 4 (right behind lamb, beef, and turkey) on a calorie-equivalent basis.
And oh by the way, the rankings of all these foods can change drastically depending on how they are raised.
The key point for me is that, as the author of this piece concludes, there is no definitive "last word" on what's best, because there are just too many variables and tradeoffs:
"...which means there’s not a lot of room for sanctimony. While I think we all need to pay attention, vegetarians shouldn’t tell omnivores to eat quinoa instead of pork any more than omnivores should tell vegetarians to eat venison instead of quinoa."
How true. I'm sure we've all encountered those who will very insistently provide their take on environmental matters, and not just on food. For example, take my neighbor "please!" - (I bow to Henny Youngman) - who nags the rest of us about getting downspout rainbarrels, or even our county board member who is spearheading a campaign against plastic water bottles. Each radiates moral certitude, and each deploys only the facts that fit his/her personal views.
We've all got to make our own decisions, but - here's another good thought - in the long run the best way to reduce our impact on the planet is for us humans to stop reproducing so fast. Ah, but thereby hangs a far different tale.
Comments