I know farming will create some to run the machinery and transport the meant and milk but isn't it a closed loop for the cattle? They eat grass for energy. They use that energy and create CO2. But the grass had to pull the same amount of CO2 out of the air to store that energy right?
Is it that the other gases are more harmful or is there something I'm missing?
The other issue is that grassland absorbs less CO2 than forests, and lots of forests have been cut down in favor grassland suitable for grazing animals.
Cows don't have little nuclear fusion reactors in their rumens, producing carbon from other elements, nor do they eat fossil fuels.
Every atom of carbon "emitted" by a cow was taken from the atmosphere by a plant, likely a year ago at most. Now, methane is a more potent greenhouse gas than CO2, but it breaks down over time. The cycle can be perfectly "sustainable".
Much of the land in the United States that is currently occupied in grazing cattle was formerly inhabited by vast herds of American bison, an animal so genetically similar to domestic cattle that they can actually interbreed, yet the methane emissions from the bison didn't bring on a global climate crisis. Why not?
For 2, we “turn” cows faster by killing them to eat them (rather than letting nature sort it out). So that 2x is then multiplied by some factor
For 3, our consumption habits have exported the cow to new environments where bison were not native (like Brazil).
(citation needed)
> For 2, we “turn” cows faster by killing them to eat them (rather than letting nature sort it out). So that 2x is then multiplied by some factor
Neither the absolute number nor the turnover rate matter. Only the raw amount of biomass. The turnover rate has nothing to do with the fact that essentially all the carbon emitted by the cow was recently removed from the atmosphere by a plant, making the whole process carbon-neutral.
> For 3, our consumption habits have exported the cow to new environments where bison were not native (like Brazil).
I limited my observation to the United States for a reason, but okay, I'll bite. How does a cow being "in Brazil" change the fact that any carbon it emits was almost certainly removed from the atmosphere by a plant within the last year, making the cow's digestion effectively carbon-neutral?
About 95mn head of cattle in the US. https://www.ers.usda.gov/topics/animal-products/cattle-beef/...
Why would I make up such a specific number?
Most US beef and dairy cows also eat hay / grain that's been grown commercially (using a lot of energy to plant, fertilize, harvest & transport). It's cute to think cows just wander around grassy fields eating naturally occurring 'carbon neutral' grasses, but there's a reason one sees so many bales of hay at dairy farms.
And a cow being 'in Brazil' means it's standing where the rainforest used to be.
That's not answering my question.
Any atom of carbon emitted by a cow was almost certainly removed from the atmosphere by a plant quite recently, yes?
So how is that not a carbon-neutral cycle?
We're talking about the specific claim that cow digestion, in and of itself, leads to increased carbon levels in the atmosphere. Clearly it does not, and cannot.
Talking about the rain forest is shifting the goalposts.
Note that North America has more forest land than it did a hundred years ago, largely because modern mechanized agriculture has dramatically increased the crop yield per acre, leading to marginal agricultural land being returned to forest cover.
The "slash-and-burn" agricultural methods that destroy the rain forest are largely a feature of the "low tech" "traditional" "organic" farming techniques that are beloved by environmentalists.
Bro, I'm answering your question as to why cows cause a global warming crisis and bison did not.
You're intentionally being obtuse on that point though, right? Like yeah, cows may be just like bison in a very very narrow frame of reference, but bison did not get their food trucked to them & they did not cut down trees to graze (both of which are things cows require now).
That's why. Period.
EDIT: If you want to narrow your frame of reference even further & just talk about methane, then 1) It's not the main culprit so I guess we agree there. But again, Global Warming is a cumulative thing, so they fact that they product that methane AND require carbon emissions to exist is pretty bad. 2) Yeah, it's a crude estimate, that's why I almost doubled it to give you the benefit of the doubt.
I'm addressing the specific, and oft-repeated, claim that cow farts as such somehow magically put more carbon in the air than there was before.
Now, there may be other issues associated with cattle raising, but that is not, and has never been, my point.
Since you apparently do not dispute my main point, I think we're finished here.
P.S. After reading your reference on the pre-European number of bison more carefully, your claim of 30 million is not supported at all by the author. The previous estimates given in the paper range all over the place, up to 1 billion (!). The author is careful to point out that all of those numbers are more or less junk, and the only conclusion the author actually makes is that there were "likely" "tens of millions" of bison.
That does not match your claim of a hard 30 million.
And btw, what's your endgame here? Climate Change denialism? I hope not, b/c that's a real bummer.
Just as I said.
I'm not sure why that counts as "moving goalposts".
And my "endgame" here is to not doom billions of people in the Third World to starvation because modern agricultural methods offend the sensibilities of privileged white people living in an affluent society.
That number is just for the "western prairies", when in fact bison were found throughout the entire North American continent.
The author is also careful to point out that this number is, at best, a crude estimate.
The stable populations of both may have in fact been about half of their peak. And while that doesn’t absolve us of anything, it may mean when we are building a report card for our current progress, we may be setting the bar a little high, and could be directing some of that energy elsewhere.