I am having a tough time wrapping my head around this study’s finding that grass-fed beef carries a greater carbon footprint than that from feedlots.
“It’s related to the much higher volumes of feed throughput and associated methane and nitrous-oxide [GHG] emissions.” He added that most pastures were highly managed, and subject to “periodic renovations and also fertilization.” Finally, with grass-fed cattle “there is also a high [grass] trampling rate. So the actual land area that you need to maintain magnifies that [GHG] difference,” Pelletier said.
I asked Shannon Hayes, a farmer, author of The Grassfed Gourmet and someone who’s readily offered meat advice in the past, about this.
She’s a farmer and an advocate, and not impressed with the argument. She’ll be on travel for a few weeks, but offered a first take.
Thanks for sending this along. i will have to look through the article
more thoroughly and construct a proper response on my website, but it
looks to me like propaganda. Increasingly, as grassfed meat gains more
market acceptance, I’ve seen more of this.
Grassfed cattle do have higher methane production. That is because, when
they have a natural diet (not grain), it is higher in roughage. A grain
diet unnaturally suppresses enteric fermentation in the animal’s rumen.
That’s why they don’t burp as much. It is also suspected that the
unnatural supression of the enteric fermentation process reduces the
nutritional value of the meat. But that’s another story.
Dr. Rita Schenck at the Institute for Environmental Research and Education
studied the net impact of grassfed cattle and determined that, because of
the carbon sequestration, even with the increased burping and farting,
there is still a net reduction in carbon emissions at the end of the day.
See my article posted at grassfedcooking.com titled Methane Production in
Grassfed Livestock for more guidance.
In this story segment you sent, one problem I see is that Pimmental was
comparing cattle to cattle, but I can’t tell if he/she was considering the
full impact of the whole feed production process. He only considered what
the cows ate, then what burped and farted – he did not consider the
ecological issues surrounding HOW that food was produced. A lot more
fossil fuel(and therefore carbon emissions) is required to grow the grain,
fertilize and spray it, harvest it and transport it, than is required to
to grow grass in place, then have the animals walk over it and eat it —
EVEN if the grasses were sprayed with fertilizers. For the record, I know
of NO farmer who is worth his salt who would spray fertilizers on his
pastures. If he or she is doing their job and managing the pastures
correctly, then the cattle are restoring nutrients to the soil, and the
use of fertilizer would be a waste of money. Also, when the pastures are
managed correctly, they come back stronger and stronger, AND better able
to sequester more carbon. Pelletier does not mention carbon sequestration
in the section you sent me.
As for trampling the grasses, that sounds just plain silly to me. This
“scientist” doesn’t seem to have walked in a real pasture managed by a
real farmer. I don’t even know what she or he is implying with this. The
statement is very vague. In fact, the hoof action across the soil (in
properly managed, not OVER GRAZED pastures) helps to build soil fertility,
as well as helps the ground to capture more water, which increases our
clean ground water supply, reduces run-off, and increases the land’s
resiliance to drought….making it far more stable in a global climate
All in all, this sounds pretty suspect to me. One other point I’d like
to make is that I do take issue with the singular, reductionist view of
considering ecological issues simply in terms of “carbon emissions.” I
agree that they are bad, but isolating our environmental concerns down to
one single variable is dangerous thinking. Bio-diversity must be
considered, as well as the pollution of our air, soils and water by so
many other chemicals. Soil erosion is a serious issue. Food security
with minimal reliance on fossil fuels is also a critically important
issue. When you look at all these things as the big picture, the choice
of grass-fed over grainfed is a no-brainer. The only way to try to keep
the conventional ag business looking halfway decent in the public eye is
to narrow the issue down to a cow burp, and as the entire argument above
outlines, that technique is highly suspect.
(Hat tip: NYT’s Bitten blog)