Conditions of sustainable civilizations

Lasting (enduring) civilizations manage to preserve knowledge indefinitely.

Theses on the conditions of lasting civilizations

1. Population in lasting civilizations does neither grow nor decrease in the long term.

Population numbers can fluctuate within limits, but the average growth is zero.

Any intermediate fluctuation must maintain the essential knowledge, ruling out disruptive all-out competitition for individual survival (unless survival of some can be ensured and information can be stored to be re-learned)

1. Lasting civilizations do not produce waste.
2. Lasting civilizations do not consume anything that is required but no longer retrieveable from their environment with adequate effort by means certain to be available in the future.

Increases in knowledge can make it possible to reduce the efforts of retrieval (within natural limits), but a gamble on such increase will sometimes not work, so long term existence requires certainty about retrievability.

Lasting civilizations use what remains available by known means and what is replentished at the same rate. Carbon and hydrogen in various forms would seem prime candidates, while a lot of other materials we now use seem less plausible. Technical cycles for other materials might be possible, but they must be closed.

1. Lasting civilizations manage to contain internal threats (e.g., conflicts) from reducing their population below critical lower limits or impeding its ability to pass on knowledge
2. Lasting civilizations manage to avert destruction by external threats (e.g., asteroids, averse climates, reversal of magnetic poles). This would seem to require significant technical capabilities.
3. Lasting civilisations manage to survive internal and external threats that are beyond its control (resilience).
4. Lasting civilization uses practices that can be sustained and is organized to be resilient against threats beyond its control.

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