🚀 go-pugleaf

In order to measure the sustainability of any proposed economy/technology, it is
useful to adopt a figure-of-merit that provides an estimate of how long it can
endure before collapse. One such FOM is what is sometimes called the Thirty-
Seven Percent Rule.

If we assume that once an economy can no longer draw on an external reserve of
materials, and must sustain itself entirely by recycling its internal stocks,
that its annual unrecoverable loss rate to the external environment of such
materials is given by r, and that it can sustain an aggregate loss of 63 percent
of its stocks before undergoing collapse, then for values of r less than about
.1, the endurance, or length of time before collapse occurs, is approximately
1/r.

Therefore, if we require that, to be tolerably sustainable, an economy should
endure for at least 1000 years, then the annual unrecoverable loss to the
environment would need to be held down to less then 1/1000, or about .1 percent.

What are the achievable values of r for each of the actual or conceivable
economies and technologies we can imagine? How must people live, work, and
use materials to get values of r down to less than 1/1000?

It turns out that to even get it down to less than 1/100, it would be necessary
for people to abandon scattered living on the surface of the planet, and move
into compact cities that try to recycle all materials.

To achieve values of r less than about 1/10,000, is is necessary for such cities
to even recycle their air, and become totally sealed from the environment. To
endure for more than 10,000 years, even the losses of materials due to evaporation
becomes significant.


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starflt@uunet.uu.net, jdr@starflight.corp.sun.com
Jon Roland
Starflight Corporation, 1755 E Bayshore Rd #9A,
Redwood City, CA 94063-4142, 415/361-8141