permaculture

[Toby Hemenway <hemenway@jeffnet.org>]

Claude, quoting Geoff Lawton, wrote:

>> Sustainability means returning more to the sytem than you take out. Period.

Dawn replied:

> If you look at this policy in terms of mass, it would actually cause your
> system to grow. I think sustainability means perfect maintainance instead of
> growth. 

Gotta agree; Geoff is describing growth, not sustainability (that dogmatic
"period" [full stop for our UK friends] really bothers me). What you return
to the system has to come from somewhere, so you're depleting some other
system. A good design will minimize imports, close the cycles. ideally, a
system should need only enough imports to offset the losses from friction
and other consequences of the 2nd law of thermodynamics. Sunlight +
photosynthesis should give you this, rather than needing us to return things
to the system.

Paul Hawken (I believe) said something along the lines of "sustainability is
merely the midpoint between destruction and regeneration," implying that for
now we need to do better than simple sustainability. I think that's what
Geoff is getting at; treading water won't keep you from drowning eventually;
you've got to swim to safety.
> 
> I'd like the definition of
> sustainability to mean maintainable into the indefinite future. It seems
> like a lot of texts want to make sustainability defined only over a
> given (rather short) time period.

Most definitions of sustainability are laughable in that they refer to
"sustainable growth" or "sustainable in alignment with economic policy" (an
earlier post linked to some of these). This is because most definitions have
to be made politically palatable. And in some cases, more excusably, a short
time frame is all that can be realistically grasped or predicted for (as
Keynes said, "in the long run we're all dead"). All systems undergo
unpredictable perturbations; straight-line extrapolations always wind up
wrong (read the first edition of "Limits to Growth" to see how wrong they
were). To assume we'll continue resource use, or whatever, at the current
rate is a poor assumption. Thus trying to assess whether a particular action
is "sustainable" is terribly difficult. I think that's why short time-lines
are used; it results in defensible assumptions.

My personal take on sustainability: Sometimes I try to imagine that the
effect of each of my actions is local instead of invisibly far off. So, if I
buy a new computer (just did), I picture an enlarging hole in my front yard
that the metal ore came from, an oil well outside my window chugging away to
make the plastic, and a landfill outside my door stuffed with the waste that
the manufacturing process and packaging created. This usually slows down my
shopping urges. If we can actually see the effects of our actions, we may
begin to act sustainably. This little visualization exercise works well to
show non-Green people their ecological footprint, BTW.

Toby