Yes, I understood it to be 10:1 measured by fossil fuel energy in, food calories out. It is still a totally meaningless metric. As I said, that makes lard measure better than lettuce, simply because lard has more calories. Not a good metric at all.
It is a process of converting one form (fossil fuel) to another form (food) that is useful to us in different ways. So the comparison just isn't apples:apples. Let's make some other comparisons:
Let's say a potato takes 10x (or whatever) the water to produce it than it contains. Is that "bad"? Sometimes we need a potato, not water.
A solar PV panel is about 10% efficient in converting sunlight to energy. Does that make PV "bad"? No, because sometimes we need electricity, not sunlight.
How many calories of sunlight does a lettuce plant absorb for each calorie of food energy it provides? Is it a useful measure if we want lettuce and not sunlight?
We don't eat fossil fuel, but if it is cost effective, we can use it (convert it) to food that we do need. That can be a good thing.
Fossil fuels are still relatively cheap, so we can afford to have an angels-on-the-head-of-a-pin debate on what "food miles" really means at this point. But in the future, with fuel supplies dwindling and corresponding price increases...I think all bets will be off.
But presentations like this don't seem to discuss it, they seem to just say "food miles is bad". And I don't see it as an "angels-on-the-head-of-a-pin debate", it is a very pragmatic debate. If it was cheaper to grow the food locally, I bet that "greedy capitalists" would choose that path.
And when fossil fuel makes it impractical, then producers will adapt and seek alternatives. But it just seems silly to me to say, "prices are going up in the future, so stop using it now". BTW, my GPS and soil test example was just the first to pop in my head regarding technology - I didn't mean it as a major contributor, but one of thousands of contributions that together lower the price of food.
Let me end on a positive note: We are probably more in agreement than you think. Sustainability is important, and there are probably some great cases to be made for some local products/processes. I think it is counterproductive to use bad metrics and "feel good" talking points to push an agenda. Think about ethanol as fuel, for an example - "We grow it here in the midwest, it comes from corn, blah,blah, blah. And ethanol is an economic and environmental disaster - but a lot of people felt good about it.
If this "sustainability" agenda is going to have legs, they need some real-world positives that are clear wins and are economical. They won't need to "sell" it, people will buy it because it is the best choice. I suggest they focus on those and drop the useless numbers and "feel good" prattle and accentuate the pragmatic positives.
-ERD50