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

I question this big time . The old ways of farming had brought the land to a
state where chemical fertilisers became a necessity to get to the  highest
yield possible.
Cultivation of the soil interfere with the natural fertilisation process
and render the necessity to steal some energy from the outside to ,( at the
best of organic farming, ) maintain with lot of pain the fertility.
Only Nature is able to increase fertility and top soil !  with the Natural
way of farming presented by Masanobu Fukuoka which we can approach that at
the most.

>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.

That is not enough , Modern organic will prove itself as unsustainable  in
the long term ( tho it will do way better in the mid term )
The tendancy here in North america  is to become more and more refined in
fertilisers and treatments of diseases.. Organic farming will slowly and
surely come back to the same place than chemical agriculture with the same
problems of unbalanced soils and diseases.
a successfull organiser of an organic farm in California is in the process
of moving to Salt spring and showed us his movie "Beyong organic" . He want
to quit because at least at the human level it is not sustainable, The farm
is successfull but the man is worn out !

>
>Over here are quite some good ecosystems left.

Come to visit  what is left of  the Temperate rain forest of Canada before
it disappear and you will have a glimpse on how the "wild ecosystems " of
europe are very poor in comparaison. The degradation started with the roman
there , here just 100 years ago.




) ?
>
>Well, paper wood is mostly from "weak" wood, and a some more from managed
>forests in Europe and Skandinavia. Not a big problem.

i wish it was true  here,  good lumber wood ( by european standard ) are
turned into pulp what is harvested in europe as good wood is left to rot on
the ground nor even more frequently just burned to make room for new
seedling , And canada is exporting its paper to Europe!
the economic reality have nothing to do with "good sense"

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

It is requiring more than switching to organic farming!

>I think you do realize, that these figures apply to all countries with
>"developped" agriculture as well.
>
most of the other countries can't afford the luxuary of modern organic
farming, so the peoples who want change go to Natural way of farming.
Masanobu Fukuoka got invited by the ministry of forestry in May  to help
them  find alternative to their "so called sustainable traditional way. "
 and there they recycle everything on their cultivated land , even poop )
their forest suffer.anyway .
The ecological impact  of a cultivated ( plowed) field is way beyong its
physical boundaries..


jean-claude