FACTORS affecting how long it will be POSSIBLE-to-SUSTAIN the Crew of Space-Ship-Earth:

 1. The INTEGRITY of the Crew of Astronomically-Tiny-Space-Ship-Earth; their abilities to Communicate, Cooperate and Learn.

 2. The Total-Isolation of Space-Ship-Earth as regards the Most-Coveted-Material-Resources in Space-Ship-Earth.

 3. Exponential-Growth-Rates-of-Populations - - - Especially in Low-Consumption-Rate-Per-Capita Parts of The-Ship.

 4. Exponential-Growths of Per-Capita-Per-Year Consumption-Rates of Exhaustible-Finite-Supplies of Material-Resources - - - 

    including:
    a. Fossil Fuels: Oils, Coals, Natural-Gas, U-235, U-238 and Thorium of various degrees of purity/accessibility.
    b. Uneven Geographical-Distributions and Political-Contexts - - - of where the Material-Supplies are in The-Ship
    c. Environmental-Degradations in acquiring, transporting and Purifying Available-Supplies.
    d. Environmental-Degradations in Manufacture, Use-with-Energy, Recycling, and Land-Fill-Disposal of SOLIDS.
    e. Environmental-Degradations due to Polluting by Non-Bio-Degradable-Non-Recycled: Plastics and Volatile Materials.
    f. Environmental-Degradations due to Genetically-Modified Life-Forms Crowding-Out Genetic-Diversity.

 5. The absence of: Trust, Cooperation, Colaboration, and Agreement-on-Scientific-Facts regarding Objective-Realities
    and Objective-Descriptions-of-Objective-Relationships/Processes.
    a. How increasing concentrations of Carbon-Dioxide and Methane in Earth's-Atmosphere Causes-Global-Warming.
    b. How much humans have been increasing such concentrations during the past 100 years.
    c. How impossible it is to understand Global-Warming that Has-Occurred - - - without being honest about human effects.
    d. How much faster than ever anticipated, ice around the world is NOW melting and Profoundly-Changing Space-Ship-Earth 
    e. How much Ocean-Waters are likely to flood the Mega-Cities of Half of the Crew of Space-Ship-Earth in a few lifetimes.
    f. How fast the Crew-of-Space-Ship-Earth will inevitably have-to-give-up relying on Disappearing-Fossil-Organic-Fuels.
    g. How utterly interdependent all forms of life are within this Astronomically-Tiny-Space-Ship-Earth.

 6. The absence of: Consensuses about Reliable-Clusters of reflexive: Ideals, Values, Principles, Virtues, etc.

 7. The absence of Mutual Understanding-and-Respect among people with different Religious-and-Cultural Heritages.

 8. The absence of: Consensuses about Reliable-Ways to Mitigate-our-Own-Alienative-Conflicts and Enduring-Alienations.

 9. How long humans will continue to trust Domineering-Bullies, Mobbing-Mobsters, and Concentrators of Wealth/Powers.

10. How long humans will continue to try to Win their Collusive-Games-of-Mutual-Self-Deception.

11. Levels-of-Consensus about what are the Essential-Complementary-Aspects of Being a Sustainable-Civilization.

12. Levels-of-Consensus about what are the Essential-Complementary-Aspects of Healthy-Reflexive-Relationships.

13. Levels-of-Consensus about what are the Tragic-Core-Aspects of Destructive-Reflexive-Relationships.