vtsnowedin wrote:emordnilap wrote:vtsnowedin wrote:we could feed the world easily if we ate the grain directly rather then feeding livestock for meat. OK if we want to do that we are going to need pretty much the same amount of grain that we are growing today.
That bit doesn't make any sense.
For the sake of argument I was accepting the figures in Table D in the paper posted above. Now make up my mind are we eating soya and grain or are we eating meat and potatoes?
http://www.thelandmagazine.org.uk/artic ... m-itself-2
I don't think you understand the energy inputs and outputs, though I am happy to stand corrected.
For example, a large portion of the energy contained in a given cereal that is fed to a cow ends up as inedible bits of the cow and/or heat necessary to keep the cow alive that then escapes into the environment. If that same cereal is fed directly to a human, all of its embodied energy ends up inside the human, making for a massive energy saving overall. In short, there is a far higher EROEI on an acre's worth of wheat as there is on an acre's worth of beef.
If you don't believe me, go and look up the numbers on how much tonnage of beef can be raised from a closed system of a given average of land and how much tonnage of, say, potatoes can be raised from that same closed system of land. Then convert the tonnage of each food type into energy in the form of joules or, calories, if you prefer. The difference is massive and it relates directly to the energy that the cow needs for itself to say alive.
Indeed, if one wanted to raise the kind of protein and other nutrients that beef provides, one would be far better off raising something like locusts. They do not return the same calories per acreage as vegetation, but they are massively better than cows. They also have the added advantages of being able to eat just about anything. The way to raise them is in a sealed building. All they need is a bit of water and biomass chucking at them.
All we need to do now is to wait for times to get tough enough that people become desperate enough to start to look at alternatives.