Certain memes become so widely repeated they eventually evolve from manufactured propaganda to conventional wisdom.

Exhibit A on that list is “Eating meat is destroying the environment.”

The source of that allegation is based on a trifecta of issues: Raising livestock requires feed, which consumes energy and water during cultivation, harvesting and processing. The “by product” of such production is manure, which can cause pollution of surface and groundwater. And the animals themselves produce greenhouse gas emissions, which exacerbate climate change.

It’s that final factor that activists have seized upon like a pit bull on a poodle, to the point that statistics are taken completely out of context to support the contention that meat should be considered a four-letter word.

Here’s a typical example of the misinformation, presented as if it were a given:

“Meat consumption has had adverse effects on the environment, maybe more than we realize,” a recent article on TrendinTech.com stated. “It is estimated that meat production alone contributes to more than 14% of annual greenhouse gas emissions worldwide, and something needs to be done to . . . save the planet. Reducing the amount of meat that is both produced and consumed will help the environment tremendously.”

Not-so-sweet story

One of primary pillars of the “meat is an eco-disaster” meme is a comparative analysis of the amount of water used to produce a given amount of food. Fair enough. Water — not oil — is likely to be the world’s most precious resources in future decades, many experts predict. It is entirely valid to evaluate the efficiency of various food sources in terms of water use, especially as so much contemporary cropland is irrigated from underground aquifers that are being systematically depleted.

As long as it’s done on a level playing field.

For example: According to numerous self-appointed “authorities” that compile charts showing water use per kilogram of various types of food, it requires only 52 gallons of water to produce “one kilogram of sugar crops,” versus a horrendously inflated estimate of 4,000 gallons of water required to produce one kilogram of beef.

But notice how the statistic is listed: sugar crops. Not edible sugar; just the crop. Even so, 52 gallons seems awfully low, given that it requires a 200 pounds of sugarcane to produce a kilo of the white stuff. The only reason that number is remotely plausible is because sugarcane is cultivated almost exclusively in tropical areas where rainfall is abundant.

Let me clarify that: Sugar cane is primarily grown in tropical areas that used to be rainforests, the world’s greatest source of oxygen production and CO2 consumption. Since the basis for eliminating meat-eating is supposedly to save the planet from the eco-destruction, shouldn’t wiping out rainforests to grow sugarcane figure in the equation?

Plus, it’s a long way from sugarcane to sucrose. As described by UNICA, the Brazilian sugarcane trade association, in a video with a script that sounds like one of those 1950s filmstrips happily touting “The Wonders of Atomic Energy,” sugar production seems to require just a bit more than the mythical 52 gallons of water per kilo:

The cane is mechanically chopped and deposited in a vehicle moving alongside the harvester, transferred to another vehicle to be transported to the mill, where the cane is washed to remove impurities, then crushed. The cane juice is chemically purified, then undergoes evaporation and boiling to crystalize the sucrose, which is isolated in a centrifuge, moved to dryers, filtered, and packaged.

The cane isn’t all that has to be washed, however. I’ve been inside sugar mills, and believe me, the rollers and belts and drums and tanks all need to be regularly washed or else they end up covered with a sticky residue the consistency of hardened epoxy.

And about as tough to remove.

Not to mention the bottom line: Sugar isn’t any good for you. It’s not even a “food!”

Beyond skewed statistics, though, the one calculation activists and their clueless disciples never seem to consider is what replaces all the meat and milk we’re no longer supposed to be eating. You can’t substitute nut milks for dairy. It takes literally ten times as much water to produce a gallon of almond milk as it does a gallon of cow’s milk.

And unless we simply downgrade our diets to include less protein and fewer calories, the meat and poultry we no longer produce and consume under this “Save the Planet” scenario would need to be replaced with other foods. Even if those are fruits, veggies and soy products, they all have to be planted, irrigated, harvested, processed, packaged and distributed, same as animal foods.

Ultimately, what’s most troubling is the assumption that if people just say no to meat, that somehow the associated problems (allegedly) linked to its production would somehow magically vanish.

Even David Copperfield is going, Uh, no — that’s not possible.

The environmental impact of animal agriculture can never disappear. It can only be replaced with — at best — slightly less energy- and resource-intensive alternatives.

There’s no magic in any of this meatless make-believe. 

Dan Murphy is a food-industry journalist and commentator