Hi Jean-Claude
first of all I'd like to tell you, that I fully agree with
your point of view on "modern society", way of living and
all the points stealing energy, soil and biomass from other
countries. This is a major point of my interest in
old cultures and their sustainable ways of living.
And a factor that led to my own way of eating and living.

To your points I'd like to add a few remarks.

>The 2 life styles are not comparable , because one proved itself to be able
>to sustain peoples in a very long term
>while the other one is unsustainable if we look at the loss of topsoil ,
>the degenerative diseases, the disparitions of species ( impoverishment in
>biodiversity) and the extension of deserts ...

This is true and somewhat unbearable (to me).
Therefore I've looked at the statistiks and done a number of calculations.
Germany, for example is very densely populated. 10 or 20 times as dense as
USA. Germany and the EU indeed produce about 95 % of the crops needed
on their own space. But at at what expense. Soil is depleted of trace
minerals. Fertilizer requires enormous amounts of energy.
And poisons are spread over the land.
And *most* of all the crop is fed some animals, which waste 90% again.

However there *are* sustainable agricultural lifestyles and have proven
over the centuries (60 centuries in europe).

I distinguish between 4 major ways of living upon a given land.

1.Hunter gatherer requires about 10000 ha per person of good woodland.
  long term sustainable
2.linearband (very first agriculture) the harvest was very small   compared
  to today, but it sustains about 1000-1200 as much
  people (10 ha per person), but only of good soil. With much safety
  included. I have some more details available. Long term sustainable.
3.modern organic (long term fertilizing with intermediate plants only).
  Harvests about 1800kg spelt per ha. or 40000kg carrots.
  Needs 0.12 ha per person.
  Long term sustainable. Needs very little external energy in form of
  tractor fuel (could be grown on some additional space too).
  One organic acre is producing nearly the same yield if having fruit trees
  grown   (for about 5-10 people year round needs per ha in terms of
  energy and protein).  See
  http://www.hort.purdue.edu/newcrop/morton/index.html
4."conventional"
  harvests about 6000-8000kg wheat per ha.
  high energy demand for producing fertilizer.
  high toxin load, soil depletion, limited time soil would bear it
  high imports with "power food" -soy fish flour, crops from foreign
  countries (including USA, but often poor).
  In this way able to nourish itself *with* producing 250g meat per day per
  person.

I think it's obvious that the *only* way to survive in the long term
for humanity (without killing 95% off) is option 3: modern organic.

Example Germany: It has about 1/3 of its space as wood (really, i was
astonished too). Of the rest some 12 mio ha are fields.
This are about *double* the acres as necessary
to nourish the 80 million people in the organic and sustainable way.
But not if you produce much meat out of it (because 90% is lost then).

>You also forget something essential in your comparaison. It is , that the
>energy necessary to maintain those 20 million peoples is not coming from
>the space where they live but is,  for the most part , stolen from
>somewhere else .

Well, very much oil from under the north sea and from arabia.

>how much food is produced by south west germany ?

Enough , but at which cost.

> where do the fertilisers,
>necessary to compensate the lost of fertility caused by agriculture ,come
>from ?

From the own chemical industry, from foreign oil.
But the mineral depleted and deteriorated soils need to be rebuilt.

>How many species  of animals and plants or hunter -gatherers  had
>to disappear to allow this overpopulation of civilised human  and
>domesticated animals and plants?

Over here are quite some good ecosystems left. And few species are
endangered (as opposed to the tropics, due to worls wood and crop demand).
However it would be a better feeling to leave 50% of the land to the nature
and use the rest 50% of the fields in a sustainable non-toxic peacefull way.

> How many whole ecosystems  had to disappear to be able
>to sustain their "need"   for consumerism, ( like the temperate and
>tropical
>rain  forests  to produce paper wood and new agricultural land to feed the
>domestic animals of Europe ) ?

Well, paper wood is mostly from "weak" wood, and a some more from managed
forests in Europe and Skandinavia. Not a big problem.
Building wood often comes from the tropics, and many refuse to use them.
Animal fedder..... *much* soy from north and south america.

>South west germany is not sustaining thoses 20 millions peoples , it is
>sheltering them from seeing the rest of the world,

It is not self sustaining, but it could, and i whished it would.

I think you do realize, that these figures apply to all countries with
"developped" agriculture as well.

regards

Amadeus S.