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"Cow methane is biogenic; it doesn't count."
cattle methane lasts about 12 years in the atmosphere, but in that time it warms far more than CO₂. That's why cutting methane is one of the fastest ways to slow warming, and the UN estimates that agriculture, mainly livestock, accounts for about 40% of the methane emitted by human activity. The claim that a stable herd causes no further warming only holds if the herd doesn't grow, and it does. And the methane from a stable herd still keeps the planet warmer than it would be without it.
Short answer
Methane lasts about 12 years in the air, but during that time it warms much more than CO₂. That's why cutting methane is one of the fastest ways to slow warming. The UN estimates that agriculture, mainly livestock, accounts for about 40% of methane from human activity. A stable herd wouldn't cause further warming, but herds are growing. And even if stable, a herd keeps the planet warmer than it would be without it.
For children
Methane is a gas cattle release when they burp. It doesn't stay in the air very long, but while it does, it warms the planet much more than other gases. Since there are billions of cattle, that makes a difference. If there were fewer cattle, the planet would cool a little quite quickly.
"If cutting methane cools the planet quickly, why not shrink the herd?"
Como pode aparecer
"Methane disappears in 12 years."
"Cows have always burped."
"The problem is oil, not cows."
"Bison were burping long before cattle."
"Under the GWP* metric, stable herds cause no additional warming."
"Livestock pollutes little; the problem is fossil fuels." (which is H12)
The strongest version
"Methane disappears in 12 years. Cows have always burped."
Strongest version (steelman):
- P1The methane emitted by cattle is part of a biological cycle: the carbon comes from plants and returns to them.
- P2Methane breaks down in about 12 years, unlike fossil CO₂, which accumulates for centuries.
- P3A herd of stable size keeps methane concentration constant, with no additional warming.
- CSo cattle methane shouldn't be counted like fossil fuels.
P1 and P2 are true. P3 is technically correct for a stable herd. The problem lies in the conclusion: herds are growing, the methane already emitted keeps the planet warmer, and cutting it would bring rapid cooling.
The argument is valid for stable herds. Its soundness fails because herds aren't stable, and because "not warming further" isn't the same as "not warming".
Full answer
- a
Reconstruction and diagnosis
The argument has a correct technical part and a wrong conclusion:
Claim Status Methane lasts about 12 years True The carbon in cattle methane comes from plants True A stable herd causes no additional warming Technically true So cattle methane doesn't matter False: herds grow, and methane already emitted keeps the planet warmer - b
Where the argument breaks
1. Methane is a very potent greenhouse gas.
Over 20 years, it warms dozens of times more than the same amount of CO₂. Its short life makes cutting it especially effective.
2. Agriculture is the largest human source of methane.
The UN's 2021 methane report estimated that agriculture accounts for about 40% of human-caused methane, with livestock as the largest source within it.
3. Herds are growing.
The world's cattle population has increased in recent decades and tends to grow with demand. More animals mean more methane and more warming.
4. "Not warming further" isn't "not warming".
A stable herd maintains a level of methane that leaves the planet warmer than it would be without it. Shrinking the herd would bring real cooling.
5. The comparison with bison and other wild animals doesn't hold.
Today, the mass of farmed animals is about fourteen times that of all wild mammals, and those animals occupy land that could store carbon (H4).
- c
Data and sources
Source What it says Note UNEP, *Global Methane Assessment* (2021) Agriculture accounts for about 40% of human-caused methane, and livestock is the largest agricultural source Report by the United Nations Environment Programme Agri-Pulse, on the FAO report *Tackling Climate Change through Livestock* (2013) Livestock supply chains account for about 14.5% of human greenhouse gas emissions In 2023, the FAO revised the estimate to about 12%, a figure disputed by researchers who consider it an underestimate Bar-On, Phillips and Milo, 2018, *PNAS* Farmed animals total about 0.1 gigatonnes of carbon; wild mammals, about 0.007 The distribution of biomass on Earth - d
The strongest counter-reply: the GWP* metric shows cattle warm less
The most serious version cites the GWP* metric, which treats short-lived gases differently and shows that stable or declining herds contribute little additional warming.
- e
Why the counter-reply doesn't reach the conclusion
GWP* itself shows that shrinking the herd cools.
Used correctly, the metric indicates that reducing the herd would bring rapid climate benefit.
The metric doesn't justify keeping the current level.
It measures additional warming, not the warming already caused.
- f
Back to the moral question
Even if cattle methane were harmless to the climate, the cattle would still be raised and killed. The climate argument, however important, doesn't answer the central question: is it fair to kill animals when we don't need to?
Reasoning errors
Logical
Is the form valid?
Equivocation
Epistemological
Does the evidence support it?
False factual premise
Selective use of metrics
Biases
Motivated reasoning
A technical detail becomes a justification for not changing
General literature on motivated cognition
Extrapolations
The principle being tested is: "if a pollutant breaks down quickly, it doesn't matter".
If it applied to…Urban air pollutionTap to see
It wouldn't matter, because it disperses within days
No one concludes this
If it applied to…Wildfire smokeTap to see
It wouldn't matter, because it disappears
No one concludes this
If it applied to…Methane from gas leaksTap to see
It wouldn't matter either
The same gas, in the same way
Contradictions
But not cattle methane.
Which contradicts the premise of stability.
The metric itself would point the other way.
What the argument gets right
What is true
There is a real difference between methane and CO₂, and the GWP* metric captures something important about short-lived gases. It's also true that the carbon in cattle methane comes from plants, and that fossil fuels are the biggest climate problem.
But
But these truths lead to another conclusion: since methane is short-lived, shrinking the herd would bring a rapid climate benefit. Cattle methane counts, and a lot.
Connections
Usually comes before
Usually comes after