On Wed, 22 Nov 2006 10:49:39 -0700, Lynnet Bannion <[log in to unmask]> 
wrote:

>Philip wrote:
>
>>
>>I was speaking only of Paleo foods, not of modern foods like grains, when
>>I said that demand will eventually exceed supply to the point that it
>>drives up prices dramatically, whether it takes 10, 50, 100 or 1000 
>>years. ...
>>
>I see no reason to believe this.  It takes about 10 calories of energy
>to grow one calorie worth
>of grain.  This is not sustainable.  There is no doubt we will run short
>of that energy some day, and
>long before 1000 years passes; the only argument is about when., between
>those who believe the
>effects will show up in the next 10-20 years, and those who believe we
>have 100 years to figure out
>our problems.  Any food which takes an order of magnitude more energy to
>grow than its yield
>is unsustainable.
>

There are apparently some horticulture supporters who believe that modern 
food agriculture, while unsustainable in the longer run, can last another 
several thousand years:

From: Eden was a Garden, Not a Farm
Is Sustainable Agriculture an Oxymoron?
Published in Permaculture Activist #60, May, 2006
http://www.patternliteracy.com/sustag.html

"Horticulture is the most efficient method known for obtaining food, 
measured by return on energy invested. Agriculture can be thought of as an 
intensification of horticulture, using more labor, land, capital, and 
technology. This means that agriculture, as noted, usually consumes more 
calories of work and resources than can be produced in food, and so is on 
the wrong side of the point of diminishing returns. That’s a good 
definition of unsustainability, while horticulture is probably on the 
positive side of the curve. Godesky (10) believes this is how horticulture 
can be distinguished from agriculture. It may take several millennia, as 
we are learning, but agriculture will eventually deplete planetary 
ecosystems, and horticulture might not."

Whether modern foods become scarce and expensive or not doesn't alter my 
point, which is that Paleo foods are sure to become very expensive at some 
point, the only question being when.

>And without the cheap petroleum that causes the starchy staples to be
>cheap, it will also happen.
>When grain is grown by horticultural means (producing more calories than
>it takes to grow), it will
>be more expensive because it will embody more human labor.
>

Energy scarcity or abundance is another issue that could take up a whole 
new thread, so I won't get into it here.

>organic home gardens are generally
>well under the horticulture/agriculture limit (it's horticulture if it
>takes less than a calorie to grow a calorie, and
>it's agriculture if it takes more).  I'm sorry I've forgotten the book
>where I read about this; maybe someone else
>on the list has also read that book who has a better memory.

I did a quick search and found *Against the Grain* by Richard Manning, 
could that have been it? I also found this:

"Overall, as a generalization, global agri-business consumes over ten 
calories of petroleum and coal energy to deliver a calorie of food to your 
dinner plate." --Jac Smit, "the world's authority on Urban Agriculture" 
http://www.cityfarmer.org/deskSmit.html

Thanks for heading me in this direction, Lynnet, it's fascinating stuff.