- Widely-held unsupported assumption
- Conflating the impacts of free-living species with those of domesticated breeds of species
- Oversimplifying the complex footprint of animal ag down to methane emissions (likely based on the media's frequent claim that "cow farts" are solely to blame)
The methane emissions of ruminants due to their digestive processes (mostly from their belching, actually, not their farting) are only one source of greenhouse gases from "livestock," and greenhouse gases are only one part of the extensive footprint of animal agriculture. Animal production has many additional environmental externalities, making the impact of farmed animals on the environment nothing like that of their natural wild ancestors who once roamed the planet.
Additionally, as argued in BayNature, "Although some landscapes and habitats... benefit from disturbed soil conditions, which were once provided by native ungulates such as elk and by wildfires, cattle do not mimic those conditions. Cows use the landscape very differently than native browsers like elk or deer."
Vegans aren't saying it's somehow bad to have ruminants roaming the Earth. Of course we know that large ruminants existed in the wild; so-called livestock weren’t created by humankind from nothing. We turned them into repurposed mutants and we constantly artificially inseminate tens of billions of them into brief and highly controlled existences, replacing their wild counterparts (and prey and predators) en mass to make room for their mutant “livestock” counterparts. (Note that "livestock" animals are breeds of species, and only species can truly go "extinct.")
Since “livestock” don’t exist naturally in any ecosystem or outside of human confinement and control, their existence is totally different from that of self-sufficient autonomous free-living animals. The latter typically perform ecosystem services and, when not hunted or otherwise manipulated by people, self-regulate the balance of trophic cascades.
We are now using 45% of the Earth’s global surface to accommodate “livestock” per ILRI, a major reason, along with overhunting, that many of their original ancestors are now extinct.
As pointed out by Sailesh Rao of Climate Healers, our “livestock" are an entirely unnatural mix of mostly very young animals (essentially rapidly-growing babies) who eat much more than their biomass might warrant in a normal population mix of young and old, and they metabolize food much faster. They don't mature and age and slow down; we kill and replace them well before that point. This would impact their methane emissions.
The waste of wild ruminants would have been naturally composting rather than amassing into amounts far exceeding what can be absorbed by soils, thereby off-gassing potent nitrous oxide emissions. A third major source is the nitrous oxide emissions from the fertilizers used to grow feed, another reason the wild ruminants emissions wouldn't hold a candle to those of their domesticated counterparts. And then we've got all those CO2 emissions from slaughterhouse processing and transportation of refrigerated products, which of course no one was doing to wild bison, buffalo or aurochs.
But of course, emissions are only one of the many negative impacts that result from human demand for animal production:
- We didn’t breed, feed, water, confine, accommodate, transport, slaughter, process, package, refrigerate, or ship any of those wild large ruminants like we do our "livestock."
- We didn’t tear down rainforests to graze them and grow their feed.
- We didn’t kill wild animals to make room for them and to make sure no one else could kill them before we could.
- We didn’t fatten them up and feed them human-edible crops like wheat, corn, and soy.
- We didn’t pump underground aquifers or drain rivers to grow that feed.
- We didn’t fertilize those crops and let the fertilizer run into the ocean and create dead zones.
- We didn’t collect their feces in giant toxic manure lagoons and then spray it onto “spray fields” once full.
Shall we go on?
Hey, vegans would love to re-wild all that land currently used for accommodating "livestock" and get those wild ruminants back to do their thing (along with the complex trophic cascades that should accompany them, including apex predators). We agree they were a valuable part of our ecosystems but also had inherent moral worth every right to be here. They were also here first, but they've been replaced by the artificial food chain of animal agriculture, which is destroying our planet... remember?
In conclusion, this failed attempt at an anti-vegan "gotcha" moment needs to go the way of the aurochs.