There is an ever-popular claim going around that burping cows contribute more to climate change than cars do. We asked our climate experts to weigh in on this allegation, and they gave it a two-Pinocchio rating on the Glenn Kessler scale. Here is why:
Cows do not necessarily produce more carbon dioxide (CO2) than cars, but they contribute significantly to methane (CH4) emissions, which has a more significant short-term impact on climate change.
This is because methane initially has a higher warming factor than carbon dioxide, but it does not stay in the atmosphere for very long. So, while cows contribute to climate change, they do not necessarily drive it the same way cars do (pun intended).
Do Cows Produce More CO2 Than Cars?
As mentioned above, cows produce less carbon dioxide than cars do, but they still produce some. Like humans, cows produce CO2 when they respire, but how much CO2 do they exhale daily, and how does that stack up against cars?
On average, a cow produces about 6,137 liters of CO2 per day. To put that into perspective, a car emits 217 liters of CO2 per mile driven. On average, people in the United States drive 32 miles per day, meaning the average daily CO2 output of a car is approximately 6,944 liters. That is a difference of 807 liters per day.
Still, it is not entirely helpful to compare cows’ and cars’ climate impact based only upon their CO2 emissions because cows do not just emit CO2; they also emit methane.
Do Cows Produce More Methane Than Cars?
Cows emit more methane (CH4) than they do carbon dioxide. So, we have to discuss their climate impact in terms of methane if we will fully explain how cows contribute to climate change.
Methane as a Greenhouse Gas
Methane is a greenhouse gas, like carbon dioxide, but initially, it is 84 times more potent than CO2, meaning it traps heat more effectively. Therefore, methane emissions contribute more to global warming trends than carbon dioxide in the short-term.
Unlike carbon dioxide, which can remain in the atmosphere for thousands of years, methane only stays in the atmosphere for a decade or two. This is why methane’s overall impact on climate change is considered to be near-term.
In general, methane accounts for just 16% of total global greenhouse gas emissions. Of that, livestock is responsible for 39% of total methane emissions. As such, methane emissions are only really to blame for about 25% of the total global warming that has been measured over the last 100 years.
Methane Emissions from Cows
Cows emit, on average, 650 liters of methane a day in the form of digestive gasses, which accounts for 55% of the total livestock-related methane emissions.
Admittedly, you would have to drive your car approximately 280 miles per day to achieve the same immediate warming factor. Not that we recommend doing so, though, because, as mentioned above, those CO2 emissions will continue to fuel climate change long after the equivalent methane has left the atmosphere.
Cow vs. Car Climate Impact
Now that we better understand how cows contribute to climate change, let us revisit the claim that cows contribute more to climate change than cars do.
On its head, this statement may still appear to be accurate because cows emit a higher volume of greenhouse gasses than your average car. Yet, to compare the climate impact of cars and cows based upon greenhouse gas emissions is like comparing apples to oranges; they are not equivalent. To truly grasp the difference, you have to think in terms of the timeframe.
Cows will contribute more to climate change in the short-term due to their methane emissions, whereas the CO2 emissions from cars will continue to drive climate change long-term.
Mitigating Climate Change with Cows and Cars
Armed with this more profound understanding of what causes climate change and when, what can we do to help mitigate the progression of global warming?
Likely, you have heard extreme suggestions on all ends: Those who believe cows are the main culprit will suggest that you become vegan, or at least cut out red meat and dairy. Those who point to transportation emissions shame you for taking a road trip to grandma’s house.
The truly sustainable solution lies somewhere in the middle. So, let us take a look at what that could mean, in terms of cow and car-caused greenhouse gas emissions.
Cow-Based Approaches
If you are really concerned about the immediate contribution methane makes to climate change, there are some really interesting ways to reduce the amount of methane cows emit that are worth considering.
- Change how you feed them: allowing cows to graze will produce smaller animals that emit more greenhouse gases per body weight than animals raised on grain.
- Include alfalfa in their diets: the inadvertent consequence of grain-feeding cows is that corn and soy make them belch more. Trading one type of emission for another is not necessarily efficient. Still, by adding alfalfa supplements to a grain-feeding diet, scientists have been able to optimize their digestion and reduce belching.
- Inoculate cows against unwanted microbes: A microbiologist at AgResearch in New Zealand identified specific gut-bacteria strains in cows that increase methane production. These ancient microbes do little to help modern cows digest their food, so the team led by Sinead Leahy is working on a vaccine that will kill these belch-inducing microbes.
Diet-Based Approaches
Diet-based approaches to mitigating methane emissions, and thereby climate change, are focused on reducing the demand for carbon-intensive foods. Meat, particularly red meat, is usually considered the main offender by those advocating for diet-based climate change mitigation.
But recent studies have shown that going vegan or vegetarian actually only cuts your greenhouse gas emissions by 4.3%. That’s because we often forget to factor in how many cars are required to help us maintain that diet.
Think about it; if you live in Maine, you do not live in a natural soy-bean habitat. That means your vegetarian protein sources have to be transported to you from far away, resulting in more CO2 emissions. In the end, you would be mitigating climate change more by eating a balanced local diet, even if it included beef.
Car-Based Approaches
If you are more worried about the long-term impact of carbon dioxide emissions, focusing on your travel habits could be an excellent way to mitigate your personal climate impact. Here are a few ideas to help reduce your car-caused emissions:
- Work from home: If 2020 has taught us anything, it is that working from home does help decrease commute-related CO2 emissions. Even if you work out a deal with your boss to telecommute one day per week, you would be reducing your CO2 emissions by nearly a whole cow’s-worth.
- If you have to go long-distance, fly: flying isn’t good for the environment, but if you do have to travel long-distance (longer than six-hours), studies have shown that flying is now more fuel-efficient than driving and will result in fewer CO2 emissions.
- Carpool: This is not a new suggestion; carpooling is one of the oldest ways to reduce your environmental impact, though there are cool new tools to make it easier. We recommend checking out a carpooling app to get started.
In Summary
Both cows and cars contribute to climate change. While cows do produce less CO2, overall, they do emit a higher volume of greenhouse gasses, which causes them to have a greater initial impact on global warming.
That said, due to the nature of methane, cow-caused emissions really only contribute to climate change for a decade or two, whereas CO2 drives climate change long-term, staying in the atmosphere for thousands of years.
Therefore, while you may have to answer to your child for the environmental sins of your cheeseburger, you will definitely have to answer to your great-grandchildren for the impact of your current commute to work.