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Comment by enkid | Hacker News Reader

Sounds like BS to me. Cows would have an environmental impact both by their release of methane when they digest the food they eat, and the hydrocarbons it takes to transport them/their food etc. And the electric power it takes to support them. There's also the issue of opportunity cost, i.e. that farm land could be carbon trapping forest instead. Considering eating beef is much more energy intensive then eating the equivalent vegetarian diet, there's simply no way cattle farm is energy negative just from bacteria taking carbon from the manure.

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> and the hydrocarbons it takes to transport them/their food etc.

Obviously, if you graze sheep / cattle / goats on marginal land, or even relatively arable land (jumping ahead to your op-cost comments) you don't have to transport food to them.

Transporting grain to feed grass-eating animals is not uniquely a north-American strategy, but is much less common in other parts of the world.

> Considering eating beef is much more energy intensive then eating the equivalent vegetarian diet, there's simply no way cattle farm is energy negative just from bacteria taking carbon from the manure

Eating beef, or raising beef? Again, if you focus on large tracts of relatively non-arable land to run cattle, the numbers are quite different than if you look only at land that can support nutrient- or calorific- dense crops.

I'd suggest Simon Fairlie's excellent 2010 book 'Meat - a Benign Extravagance' for some deeper examination of the logistics / numbers here.

Our cows don't use much electricity. And I don't think the claims was about being energy negative, just carbon negative. That's an important difference. I'll also call BS, but for a different reason. The growing animal takes carbon from the soil by eating grass. If one continually harvests animals off the land, that's carbon being continually removed and taken elsewhere. What happens to that carbon downstream is complicated, but one can be sure it's not being sequestered in the ground where the cattle originated.

Replying to my own comment, because I can't seem to edit it from this mobile app.

Thinking about this a little more, I had it a somewhat wrong above. Most of the carbon that makes up the animal comes from the air in the form of photosynthesis. So if it's re-released back into the atmosphere, that's not a net gain. So I suppose to be completely neutral there would need to be an equal amount of carbon being sequestered in the soil to offset the factors already mentioned, like transport and processing. That does actually seem conceptually possible.

The great plains in the US were legendary for having multiple feet of deep, rich topsoil for farming.

Rich topsoil is that which has lots of organic matter in it, i.e. carbon.

There are people who say the great plains were built by roaming buffalo herds, grazing on the grasses growing there.

So if that natural system was able to sequester carbon it stands to reason that humans could mimic it and in doing so also sequester carbon.

We should also figure out how many millennia it took the bison to do this and whether other uses for the land could sequester more carbon.

Some regenerative agriculture advocates say soil can build up pretty fast with the right techniques that include animals: https://www.youtube.com/watch?v=9yPjoh9YJMk

Soil builds up real fast. A few leaves here and there, some dust, a little water and boom: grass, bushes, flowers. All this in several weeks to months. I've seen it happen so many times because our streets aren't well maintained. 5cm soil on concrete, asphalt, rooftops, etc.

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