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Business Advisor

How Green Is Your Meat?

Calculating the greenhouse gas coefficient of commercial meat production

It's more than the numbers
Image Credit: Eliza MacLean and Bill Beasley

I was thinking about what to throw on the grill this weekend when my friend Bill Beasley sent me an E-mail about the greenhouse gas (GHG) impact of various types of meat.

I had generally understood there was a “bovine flatulence problem” with eating beef and that it was better to choose chicken or lamb for the grill. But Bill had gone the extra mile to put numbers to the green house gas impact of commercially raised chicken as compared to Beef, Pork, and Lamb.

What he discovered made him decide to become a vegetarian…

Beef cattle produce methane (CH4) mostly from enteric fermentation, meaning digestion (and flatulence), and a little from manure management (not free-range). Their total annual methane output in 2007 was 102.4 Terra-grams carbon dioxide equivalent (Tg CO2 eq.)

Due to methane’s long shelf life (mixes well and hangs around longer), it is estimated that for equal quantities, it is 23 times more damaging to our atmosphere than CO2. We have 96 million cattle to 300 million people in America, 3 humans per cow.

Comparing this to 2007 US transportation emissions and to our residential housing industry’s annual emissions one can summarize (again, just comparing CH4 to CO2 emissions)…

  • Transportation CO2: 1,887 Tg CO2 eq.
  • Residential CO2: 341 Tg CO2 eq.
  • Beef cattle CH4: 102 Tg CO2 eq.

Our consumption of beef is equivalent to 30% of all residential GHG production, or 5% of all transportation GHG production!

So I’ll be cutting way back on the steaks and burgers this summer.

But what about other meats? Bill calculated the GHG contribution per pound of chicken, lamb, and pork from both the life cycle of the animal and the disposal of the manure.

As expected, poultry is the lowest GHG emitter, with 277 Mega-Grams eq./ million pounds (Mg CO2 eq/ 1M) lbs of meat. And beef cattle are the worst, with 1,741 Mg CO2 eq/ 1M lbs of meat, so beef has 6.3 times the GHG impact of chicken.

Second on the list is lamb, with 356 Mg CO2 eq/ 1M lbs of meat or 1.3 times the GHG impact of poultry. Most lamb is pasture raised, with very low methane production related to their manure, and virtually no antibiotics and pesticides involved. So, considering animal cruelty and the health of your family, that marinated, butterflied leg of lamb is looking pretty appetizing.

Pork barbeque, my local favorite here in NC, doesn’t fare so well with 1,121 Mg CO2 eq/ 1M lbs of meat, or 4.1 times the GHG impact of poultry. But this is largely due to the factory farm management process with over 90% of it’s methane coming from the hog waste lagoons.

But many small family farms are now producing pasture-raised, antibiotic-free pork. If we assume that pork raised in this way has about twice the waste-related methane as lamb, then we can calculate that it would come in at 125 Mg CO2 eq/ 1M lbs of meat, or half the GHG impact of chicken.

What to drink with it? Consider a glass of the greenest beverage.

I can see the marketing slogan already:

“Pasture-raised pork, the other green meat.”


  1. user-669103 | | #1

    me to
    much the same as motivated me to go vegitarian.
    One way that I explain it to people is to make an obviously radical statement:

    The planet can only support so many humans and so many cattle, pigs and sheep. Would you prefer less cattle pigs and sheep or less humans? And if you choose to keep the cattle pigs and sheep which of the humans would you like to get rid of?

    I'm still waiting for someone to answer "I'd choose to get rid of you!"

  2. Expert Member
    Michael Maines | | #2

    Small diversified farms are the answer
    Industrial-style farming and meat production do create waste and pollution on many levels, and I have dabbled with vegetarianism as one answer. There is another solution though--replicate nature's systems to incorporate the rich fertilizer produced by animals, on a scale that is sustainable. If you need a manure lagoon, you're not doing it right. is one place that is doing it right. is a publication with a lot of information on intensive pasture grazing. We need to think of agriculture the same way we think of green building; the status quo is not good enough but systainable models do exist.

  3. Brent_Eubanks | | #3

    concientious beef
    Everything in this post is true about industrially-raised beef, which is generally raised in confinement and fed a diet consisting mostly of corn and antibiotics.

    However, there are options in the beef department, at least in some parts of the country. In the SF Bay Area, Markegard Family Grass-Fed Beef raises free-range 100% grass fed beef. They use a rapid rotation system -- moving the animals from padock to padock every few days -- which optimizes the rate of grass regrowth and prevents the animals from damaging the underlying soil. In fact, the net effect is the opposite -- the animals' manure delivers most of the biomass they eat back to the soil, and the healthy soil and grass helps break that biomass down quickly (and aerobically) sequestering carbon to the soil.

    You can get more information about Markegard Family Grass-Fed Beef at the wife's website:

    Oh, yeah, and the beef is extraordinarily good. Much much better than the insipid corn-fed stuff that is the standard.

  4. Brent_Eubanks | | #4

    should have also mentioned
    Cows will always fart, but a lot of that flatulence is the result of their corn diet, which their digestive system has trouble coping with. Grass fed animals should produce a lot less methane.

  5. tom gentry | | #5

    where is all this pasture?
    The calculations in the article assume that there is a bunch of idle pasture just waiting to be grazed. If everyone switched to pasture-raised animals, we’d need to deforest most of the planet. If you factor in deforestation, you’ll get dramatically different results.
    Bill Beasley apparently looked at the big picture and decided that vegetarianism was the appropriate response. If one is unwilling to eat a plant-based diet, they should at the very least dramatically reduce meat consumption. Creating a demand for pasture-raised meats and the deforestation they require is not the answer. Unfortunately, “green meat” may be an oxymoron.


    "green meat an Oxymoron"?

    I'm with you on that. Our consumption of meat, and fuel and resources is out of control. We can't even switch to fish because the rate we are harvesting the oceans is unsustainable. And fish farming, esp open water salmon and Indonesian shrimp farming, has terrible unintended consequences. Bottom line is we have too many people living too harshly on the planet.

    My point is not that we should all switch to pasture raised meat but that, when offered a choice at the market between industrially raised meat and pasture raised meat from small local farms, we should give preference to the small farm product and, honestly, if it means spending the same amount of money for a smaller piece of food, well yeah, that's what I'm saying too.

    I'm not really calling for mass vegetarianism. I just think it makes sense to look at the big picture with all the day-to-day decisions we make and that means finding exuberance and joy in ways that are less detrimental to the planet and our fellow travelers here. I'll still enjoy some salty, fatty, smoked pork, just better quality free range pork in smaller quantities.

    Get me a side of harmony with that order of delight.

  7. tom gentry | | #7

    Well said, Michael
    We indeed need to rethink a variety of day-to-day decisions and not get fooled by greenwash. I just had a commentary published in Asheville's Mountain Xpress that I think you will enjoy. It's at

    Thanks for your thoughtful article and comments.

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