Do Cow Farts Really Significantly Contribute to Global Warming?
There are currently approximately 1.3 to 1.5 billion cows grazing, sleeping, and chewing
their cud at any given time on planet Earth.
And these 1,300 pound (average weight for both a beef and dairy cow) animals eat a lot.
Much like humans, when they eat, gas builds up inside of their guts and has to be expelled.
(See Why Beans Make You Fart) Cows fart and burp… a lot.
The result is a large amount of methane being introduced into the atmosphere.
In a 2006 United Nations’ Food and Agricultural Organization report, it claims that the livestock
sector, most of which are cows, “generates more greenhouse gas emissions as measured
in CO2 equivalent – 18 percent – than transport.”
According to a Danish study, the average cow produces enough methane per year to do the
same greenhouse damage as four tons of carbon dioxide.
So is this significantly contributing to global warming?
Let’s start with how and why cows produce so much methane gas.
Cows, sheep, goats, giraffes, and deer belong to a class of mammals called ruminants.
Most ruminants have four stomachs, two-toed feet, and store their food in the first chamber
of the stomach, called the rumen, before regurgitating it.
This regurgitated food is called “cud” and the animals chew it again to help further
break it down to make it easier to digest.
Inside of the rumen, over four hundred different kinds of microbes exist that also play a critical
role in the digestion process.
Several of these microbes create methane gas as a byproduct.
Due to the sheer number of cows on the planet, along with the large size per cow, our tasty
friends produce more methane gas than all other ruminants combined.
Why could this potentially be bad?
Methane is twenty one times more potent at trapping heat from the Sun than carbon dioxide.
Though it is less prevalent in the atmosphere than carbon dioxide, it is, by unit, the most
destructive of the greenhouse gases.
Since the turn of the 19th century, methane gas emissions have increased by 150%, according
to NASA’s Goddard Institute.
Methane gas, like all other greenhouse gases (which includes water vapor), acts like a
blanket around our planet, trapping heat.
The right amount and the planet has an average temperature of a life-supporting 59 degrees
Fahrenheit.
Too little and the greenhouse effect becomes weak, like on Mars.
Too much and the surface of the planet becomes so hot “it can melt lead,” like on Venus.
Livestock is the largest source of methane gas emissions worldwide, contributing over
28 percent of total emissions.
Wetlands, leaks from oil refineries and drills, and landfills also contribute methane gas
to the atmosphere.
In fact, unlike the ratios on a global scale, in the United States livestock is only the
third largest contributor, behind the mining and transportation of natural gas and rotting
landfill waste.
In actuality it’s not as much the farting that’s the problem, cows’ burping and
manure contribute more methane gas than flatulence.
According to researchers at New Zealand’s largest Crown Research Institute, AGResearch,
up to 95 percent of the emissions comes from the cow’s mouth rather than its behind.
It’s estimated, through whichever orifice, that each individual cow lets out between
thirty and fifty gallons of methane per day.
With an estimated 1.3 to 1.5 billion cattle in the world today, this adds up fast.
Exactly how significant this it to our global environment isn’t something that anyone
can easily put a number on, but the EPA, NASA, various global agriculture organizations,
and the United Nations all recognize that this is a real problem.
In recent years, several different solutions have been proposed.
Scientists and experts have experimented with cows’ diets to see if that could help cut
down on the amount of methane gas.
For instance, Welsh scientists studied the effects of putting garlic into cows’ feed.
According to BBC News, “Garlic directly attacks the organisms in the gut that produce
methane.”
So far, results have been positive.
Researchers have also studied adding plants that are high in tannins to the diet, which
are believed to lower methane levels in ruminants.
Another branch of study focuses on not lowering the amount of methane gas, but figuring out
a way to contain it and repurpose it.
Some farms have experimented with having their livestock live in a plastic bubble, which
takes the expelled gas and converts it into electricity.
But this process is both expensive, inefficient, and considered somewhat inhumane, forcing
animals to live inside an artificial bubble.
Methane gas emitted by cows and other livestock does have a significant impact on the amount
of greenhouse gases in our atmosphere, which are the main culprits behind climate change
and global warming.
While farts aren’t the only way cows are expelling methane, it is, at least, accurate
to say that cow farts play a part in our planet’s climate growing hotter.