Do Cows Really Pollute As Much As Cars?

Cattle burp so much methane into our atmosphere that it's the equivalent of how much cars pollute every day. Learn what researchers are trying to do about the gassy situation in this episode of BrainStuff, based on this article: https://animals.howstuffworks.com/mammals/methane-cow.htm 

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff Lauren Vogelbaum. Here,
agriculture is responsible for an estimated seventeen percent of the
world's greenhouse gas emissions, and within the category of agriculture,
cattle produced the most greenhouse gases, and it's because of burbs.

(00:25):
Cattle emit a massive amount of methane through belching, with
a lesser amount through flatulence. Statistics vary regarding exactly how
much on average, as some experts say it's some one
hundred to two hundred liters per day, while others say
it's up to five hundred. In any case, that is
a lot of methane, an amount comparable to the pollution

(00:45):
produced by a car in a day. On a global scale,
these methane emissions are about as much of a problem
as emissions from the oil and gas industry at large,
and the problem is expected to increase. A demand for
meat and milk is growing as the human population grows
and as more populations around the world are becoming able

(01:06):
to afford it. Methane is relatively short lived in our atmosphere.
It only sticks around for about twelve years, as opposed
to the hundreds or thousands that carbon dioxide can last,
but methane's effects are much more powerful. Its contribution to
global warming is about twenty eight times out of carbon
dioxide while it lasts. This is part of why some

(01:28):
climate activists and scientists are urging people who have a
choice in their diet to choose less beef so that
the world will keep fewer cattle and decrease those emissions.
But okay, let's talk about why cattle produces so much methane. Cows, goats, sheep,
and several other animals belong to a class of creatures

(01:50):
called ruminants. Ruminants have four stomachs, and they digest their
food in those stomachs instead of intestines as humans do.
A ruminants eat food, regurgitate it as cud, and then
chew and swallow it again. The stomachs are filled with
bacteria and other microbes that aid in digestion, but those

(02:10):
microbes also produce methane. The same process happens in humans too,
albeit on a smaller scale. When we fart, we are
in fact passing our microbes farts out. Life is wondrous,
But okay, this became a problem with the development of
large scale agriculture. In the mid twentieth century, when farming

(02:31):
became a big business for some companies, farms became consolidated
into large enterprises with many thousands of animals across large acreage.
Before then, grazing areas were filled with a variety of
grasses and flowers that grew naturally, offering a diverse diet
for cows and other ruminants. However, in order to improve

(02:52):
the efficiency of feeding livestock, many of these pastures became
re seeded with perennial rye grass with the aid of
art fertilizers. Perennial rye grass grows quickly and in huge quantities.
The downside is that it lacks the nutritious content of
other grasses and prevents more nutritious plants from growing. It's

(03:12):
been called the fast food of grass. This simple diet
allows many cows to be fed, but it inhibits digestion.
This is where the methane comes in. The difficult to
digest grass ferments in the cow's stomachs, where it interacts
with microbes and produces gas. Research into how to improve

(03:34):
the situation has been going on for at least twenty years.
There are lots of ideas out there, such as breeding
and feeding beef cattles that they produce more meat, thus
reducing the number of cattle needed to meat meat demand.
This thing goes for improving milk production in dairy cows.
There are also efforts to alter cattle's diet so that

(03:55):
they produce less gas in the first place. For example,
a team of resecar in Germany created a pill to
trap gas and a cow's rumen its first stomach and
convert the methane into glucose. However, the pill requires a
strict diet and structured feeding times, which don't lend themselves
well to grazing. Other experiments have tried supplements like garlic

(04:19):
or garlic extracts, the idea being that garlic contains compounds
that can kill off some of the microbes that produce methane.
It works, though with variable amounts of success, and don't worry,
it doesn't make their milk taste like garlic. A Seaweed
is also under investigation as a dietary supplement. A one
study out of UC Davis found that replacing just one

(04:41):
percent of cattle's normal diet with seaweed led to a
sixty percent decrease in methane production. Of course, growing enough
seaweed and getting cattle to eat it may prove difficult.
Many researchers are investigating ways to alter what livestock eat
and to mix the best of old cow pastures, diverse,

(05:02):
naturally growing and nutrient rich grasses, and other plants with
the best of the new, fast growing and resistant to
invasive species. One possibility is to increase the ability of beneficial,
nutrient rich plants and flowers to grow alongside the fast
growing grasses commonly used in pastures. Another branch of research

(05:23):
focuses on plants that are high in tannins, which are
believed to lower methane levels in ruminants and boost milk production,
though excessively high levels are harmful to the animal's growth.
Yet another possibility exists in trapping the methane gas and
using it as energy or selling it back to the
electrical grid. Some farmers already extract methane from livestock waste,

(05:45):
but that doesn't solve the bigger problem of belched methane.
Harnessing that methane would mean trapping it in the air,
which again isn't really conducive to letting cattle do what
they do best, which is wander and grays. It's a
difficult problem, but people all over the planet are working
to better understand cattle's digestive systems and make them better

(06:08):
for the planet. Who knew cowbirds could cause so much excitement.
Today's episode is based on the article do cow's pollute
as much as cars? On HowStuffWorks dot com, written by
Jacob Silverman. Brain Stuff is production of iHeartRadio in partnership
with HowStuffWorks dot Com and is produced by Tyler Klang.

(06:30):
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