I have some doubts about the usefulness of the water usage numbers given. Most of the water plants and animals take in is not retained long term or used in chemical reactions that break down the water. It mostly ends up being released by the organism back into the environment.
That argument misses the point, which is the ecological costs incurred by shifting that water. For example, depleted rivers effect fisheries.
Also, irrigation requires energy. The more water, the more energy. Though, I'm not sure how significant of a factor that is in the grand scheme of things.
"released back into the environment", yes, along with all of the contaminants introduced by the industrial agricultural system, and in a different place from where it started. The "water" runoff from feed lots is considered toxic waste to be managed, not a natural resource to be celebrated or conserved.
It's not a zero-sum game. There's a reason there's a (political, at leas in the US) war being waged over water in every region where water is scarce and cows are plentiful (likewise for many kinds of plant agriculture, admittedly, but the water used for the same nutritional value of plant-based foods is vastly lower).
Anyway, these are complex systems, sure. And, as with climate change science, in general, there are all sorts of variables one can debate the precision of. But, the general trend is in a dangerous direction. It's pretty widely accepted now, by folks who study the subject, that meat consumption is a large part of the equation. How much is debatable, but no one who studies the field that I'm aware of is saying it isn't a big part of the picture.
The runoff is sealed off from the environment, but water vapor isn't. This appears to be pretty well studied; for instance, just the non-waste biological activity of an indoor lot of live cows can saturate the air, which then needs to be vented.
I think 'tzs is just pointing out that the water consumption numbers here are oversimplified. They probably are, right?
Yes, they probably are oversimplified, as is almost every number we talk about when discussing climate change. It's a big topic, and very few people (maybe actually nobody) understand all of the facets of it in enough detail to speak with authority on how they all interact.
Sure. But sometimes the numbers are oversimplified but valid to a first approximation, and others (like, perhaps, the water numbers for California almonds) are so oversimplified as to be not helpful for discussion.
So then you're left wondering, which kind of number is this one? Does most of the water used to produce beef return to the environment in the course of raising the animals to their slaughter weight, or does most of it get retained in concrete and plastic lined manure pits?
On the specific issue of the carbon budget, there is a point I miss: what do we count in the carbon dioxide emission by agriculture and livestock? In both cases carbon emitted to the atmosphere is just carbon that was earlier fixated from the atmosphere, since plants and animals have no other sources of carbon (where there is a lot in the soil, but that counts as carbon that was already fixated from the atmosphere). So, while industrial activities unilaterally move carbon from oil fields to soil or atmosphere, growing plants or raising livestock just move carbon back and forth between living bodies and atmosphere/soil. In particular, it seems that having more more animals helps reducing the amount of carbon in the air (but it also requires more energy to handle them, so it increases oil usage, therefore the net effect is probably bad).
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[ 3.6 ms ] story [ 44.3 ms ] threadAlso, irrigation requires energy. The more water, the more energy. Though, I'm not sure how significant of a factor that is in the grand scheme of things.
It's not a zero-sum game. There's a reason there's a (political, at leas in the US) war being waged over water in every region where water is scarce and cows are plentiful (likewise for many kinds of plant agriculture, admittedly, but the water used for the same nutritional value of plant-based foods is vastly lower).
Anyway, these are complex systems, sure. And, as with climate change science, in general, there are all sorts of variables one can debate the precision of. But, the general trend is in a dangerous direction. It's pretty widely accepted now, by folks who study the subject, that meat consumption is a large part of the equation. How much is debatable, but no one who studies the field that I'm aware of is saying it isn't a big part of the picture.
I think 'tzs is just pointing out that the water consumption numbers here are oversimplified. They probably are, right?
So then you're left wondering, which kind of number is this one? Does most of the water used to produce beef return to the environment in the course of raising the animals to their slaughter weight, or does most of it get retained in concrete and plastic lined manure pits?