Why driving a Prius is really not enough

[Proco]

<div class='quotetop'>QUOTE(Masnyd @ Jul 18 2007, 07:43 PM) [snapback]481293[/snapback]</div>

Animals have a right to life too, just like you[/b]

What about the fruits & veggies? Regardless of what we eat, something must die.

[chogan]

<div class='quotetop'>QUOTE(sthayashi @ Jul 18 2007, 09:53 PM) [snapback]481342[/snapback]</div>

Congratulations, I've been lurking on and off on Priuschat for months, but now I finally have a question to ask and ironically, it has nothing to do with Prii.

Where does this 10 Fossil-fuel calories come from? I've not heard this figure before.

Anyways, thanks for giving me an excuse to sign up.
[/b]

Well, it's an estimate, and you can get at it a variety of ways.

The most basic is micro-costing studies of food production -- how much fertilizer, how much fuel to run the tractors, and so on. Much of the modern work there was done by an academic named Pimental at Cornell University. There is of course argument over the numbers, the estimates change over time, and what should go into the numbers can be debated, and so on, but the 10 calorie figure is the one that seems to get kicked around most often.

The best introduction to this I've found is here. You can find a bunch of others that do that as well, but this guy bothers to put in the references, but as cited in a footnote here, the Pimental's book "Food, Energy, and Society" is the usual source for the figure of ten fossil fuel calories per edible calorie, though I can't find an online summary of that.

http://bicycleuniverse.info/transpo/beef.html

Wikipedia has a long article, but you're never sure about accuracy. I thought it hit a lot of the high points:

http://en.wikipedia.org/wiki/Environ..._vegetarianism

I'm also attaching a spreadsheet I put together about a year ago. I has a page that lists a bunch of internet links. I'm not claiming its comprehensive or systematic, just that it gives you a few leads, organized, that you could follow if you wish.

The reason I'm comfortable with the 10 calorie figure is that you can also come at it from a macro level. I'm an economist, so I'm familiar with US Gross Domestic Product accounting. There is a set of reports that summarizes energy use by industry. I started from that, pro-rated portions of energy use in transport and retailing based on percent of revenues from food, added in some data on energy costs and average diet calories per person, and came up with an aggregate estimate of 14 (k)calories of fossil fuel for every edible (k) calorie consumed in the US. Which I thought was remarkably close to the 10 calorie figure, all things considered.

I don't mean to say that the "10" figure is set in stone, just that it appears reasonable based on several quite different calculations. I've seen figures as low as 7 and as high as 15. I think there's enough evidence to take 10 as a good working value for evaluating the impact of diet.

One large disconnect beteen the micro-level studies and the macro studies is that a large proportion of edible food is wasted in the US. Here's a cite from the USDA:

http://www.ers.usda.gov/publications/foodr...1997/jan97a.pdf


More than a third of the food calories harvested in the US never get eaten, at least by the USDA's estimate. So that's a rather large "fudge factor" in the calculation. The energy cost of each calorie actually consumed is therefore higher than the cost of growing the food, due to the waste. You can't directly translate the USDA data into a numerical adjuster (at least I haven't), but it's a factor to consider.

Finally, there is absolute agreement that grain-fed beef is the worst culprit, for the obvious reason that it takes several pounds of grain to make a pound of beef, and then for secondary considerations (such as, for example, shipping around the manure off the feedlots, shipping the grain to the feedlots, etc.) The data on the impact of cattle really are kind of amazing. The Wikipedia article above says that 80% of US agricultural land and 70% of US grain harvest are for feeding animals. So, in round numbers, three-quarters of US agriculture is devoted to animal products.

Which again squares with the published energy data. Taking the published estimates, if animal products account for 25% of your dietary calories, they are accounting for 75% of the fossil fuel used to produce your food. So the averages based on diet x fossil fuel calorie data, and the averages based on land use, appear reasonably similar. So, the energy cost between animal and vegetable calorie sources really do appear to be that large. There are also large, well-established differentials between (e.g.) chicken and beef, corresponding to the well-known differentials in the amount of grain required to produce a pound of meat (far less for chicken).

I switched to local grass-fed beef, but it's never easy. I mean, the beef is great, but it turns out that methane produced in rumanants' stomachs is a large source of greenhouse gases, and the rougher the diet, the larger the fraction of it that is off-gassed as methane. So, a grass-fed cow will produce more methane per pound than a grain-fed cow. I did just enough work there to estimate that the net GHG impact of grass-fed over grain-fed beef been still appears to be positive, but because methane is a vastly more potent GHG, it really matters quite a bit if you include that in the calculation or not. The same logic applies to dairy. Right now, about 80 percent of US milk is from grain-fed cows (as opposed to those picturesque cows out in the fields that they print on the milk cartons.) Because of the methane issue, it is plausible (though not proven) that fewer, larger, hormone-stimulated grain-fed cows might actually produce less net GHG for a given amount of milk, than more, smaller, un-stimulated grass-fed cows. That doesn't change my mind about grain-fed milk (it's not as good for you or for the cow), but it means that there may not be a good argument for grassfed milk based on total GHG emissions.

Well, golly, that has to be more than you ever wanted to know. See the spreadsheet for a few more random internet sources on this.

[tripp]

<div class='quotetop'>QUOTE(SSimon @ Jul 19 2007, 07:18 AM) [snapback]481535[/snapback]</div>

Even flax seed isn't a true omega, it has to be converted by the body and then the body needs to uptake it properly.
[/b]

Not only that, but you have to know your genetics. Different population groups process different diets differently. Some populations don't process flaxseed "omega3s", mostly folks from the British Isles and the like. Dessert folks (the Pima Indians, for example) don't process the American Carb overload (the American diet is very high in carbs, I doubt it's high in protein) well at all. Hence the massive obesity and diabetes issues in those populations. In fact, that's a problem in the States overall. The population is getting fatter and unhealthier. Europe and China are catching up with us. In a few decades they'll be just as fat and unhealthy as we are.

Chogan, were do you get your data on lifespan? It seems to me that there's massive skewing from other lifestyle effects. People that are vegans or vegetarians are probably a lot healthier than omni/carno types. Especially the carno types. I'd be willing to bet that they smoke a lot less as a population. There are probably loads of other factors that have nothing to do with diet that affect those numbers.

The real problem is that there are too many people and bovine food units. Our planet is too small for so many large animals.

[hyo silver]

<div class='quotetop'>QUOTE(tripp @ 2007 Jul 19 10:04 AM) [snapback]481649[/snapback]</div>

Not only that, but you have to know your genetics. Different population groups process different diets differently. Some populations don't process flaxseed "omega3s", mostly folks from the British Isles and the like. Dessert folks...
[/b]

I'm a main course person myself...

Seriously - for a change - are you saying different diets have evolved because of physiological differences?

[ohershey]

Oh, this is too damn funny. I'm reading through, trying to come up with some suitably snide comment ( you know, something like "I love cats, I just can't eat a whole one all by myself..."), when I reach the last post.

And there it is - sitting at the bottom of the page. Making me laugh with the perfect irony of the digital universe..

And the add at the bottom of the thread was:

[attachmentid=9929]

[tripp]

<div class='quotetop'>QUOTE(hyo silver @ Jul 19 2007, 11:14 AM) [snapback]481657[/snapback]</div>

I'm a main course person myself...

Seriously - for a change - are you saying different diets have evolved because of physiological differences?
[/b]

Bloody typos.

Probably the other way around. Peoples' genetics changed as they adapted to the food sources around them.

Hatter, that is too funny! You might say it's delicious.

[jamesbugman]

The way I figure it is I am helping the environment by eating a cow.

Cows produce Methane (toot) so by eating it I reduce the amount af methane production in this country, I also provide leather for my shoes, couch, wallet, wife's car seats....

Also when I eat too many veggies, I produce methane, so I remove a methane producer and prevent myself from producing more.

How can you argue with that logic

James

[Rae Vynn]

<div class='quotetop'>QUOTE(SSimon @ Jul 19 2007, 06:18 AM) [snapback]481535[/snapback]</div>

Please research this diet to ensure that she (and you) are getting all the proper nutrients. Vitamin b12 is lacking in this diet. You just aren't going to get this vitamin without eating meat. And a person can have a deficiency and the symptoms wouldn't manifest until damage is done. So, buy a supplement. I've read that this vitamin is best absorbed under the tongue (they sell ones specifically for this purpose), as it is better absorbed by the capillaries under the tongue. And, better research your protein options as we often have to eat various kinds of food in the same day to ensure a complete protein.

[/b]

One of the very best sources of B12 is Red Star nutritional yeast -- an absolute mainstay of every vegetarian/vegan kitchen that I know of!
B12 does not originate with animals. They ingest it from the food that they eat, as it is actually a product of micro-organisms.

The concept of "complete proteins", which was publicized by "Diet for a small planet" has since been proven to be unnecessary. As long as you are eating a variety of foods, such as grains, legumes, vegetables, and peas, at least within a week (if not every day), your body will function just fine. Besides, isn't it better to eat a variety of food every day, anyway?

We're all pretty familiar with the FDA food pyramid. How close are you to following that? Apparently, very few people who think that they are healthier eating animals and animal products even come close: What people are, unfortunately, really eating.

It is unfortunate that the weirdo, oddball, crazy person calling themselves a "vegan", who is truly a "junk food vegan", is the one that gets some sort of press coverage, and the thousands (millions?) of veggie/vegans who are just going along, eating real food, staying healthy, not having heart attacks or strokes, not needing Viagra or Pantax, are ignored.

[hyo silver]

Hey, Tripp. I know it was a typo; it was just too good to pass up. I know several dessert people.

So, how are we to obtain sufficient protein in a sustainable manner? I'm not sure city bylaws will allow multitudes of chickens and rabbits.

[chogan]

<div class='quotetop'>QUOTE(tripp @ Jul 19 2007, 01:04 PM) [snapback]481649[/snapback]</div>

Chogan, were do you get your data on lifespan? It seems to me that there's massive skewing from other lifestyle effects. People that are vegans or vegetarians are probably a lot healthier than omni/carno types. Especially the carno types. I'd be willing to bet that they smoke a lot less as a population. There are probably loads of other factors that have nothing to do with diet that affect those numbers.

[/b]

I take it back. I'd rembered reading that somewhere, but a quick lit search at the National Library of Medicine disproves that. The unadjusted difference in lifespan might be near that, but that's not the right comparision. I found several studies of cohorts of health-conscious individuals, and there is pretty good agreement that there's little or no difference in overall (all-causes) mortality among otherwise equally healthy vegetarian and non-vegetarian health-conscious persons. At least, not that is detectable within the limits of those studies. The only standout is a large longitudinal study of Seventh Day Adventists where vegans had longer average lifespan (by about 3 years) than vegetarians.

There is wide agreement among the studies that a vegetarian diet yields lower risk factors for heart disease and roughly 25% lower average mortality from ischemic heart disease (clogged heart arteries). But most of those predate widespread use of cheap statin (cholesterol-lowering) drugs. So nowadays, I wonder if even that advantage will hold up, as you dont' have to give up animal fat any more to lower your blood cholesterol -- just take a pill.

So, I take it back. Maybe the raw difference is that large, and there is a well-documented differential in deaths from clogged heart arteries, but that's about it. Little or no systematic evidence of lower all-causes mortality rates in modern (1990s or later) data. Guess I can barbeque tonight after all.