1. Global warming
  2. Water problems – too much or too little
  3. Aquifer depletion and/or contamination
  4. Ocean acidification – death of sea life
  5. Ocean warming – death or migration of sea life
  6. Wind storms – increased hurricanes & tornados activity and intensity
  7. Temperature fluctuations-extreme heat and cold
  8. Increased volcanic & seismic activity
  9. Reduced soil moisture
  10. Crop failure
  11. Disrupted energy transmission along grids
  12. Oil shortages
  13. Mineral depletion
  14. Over population
  15. Terrorism
  16. Chaos and anarchy
  17. Nuclear war
  18. Religious war
  19. Methane air contamination
  20. Insect plagues
  21. Drug resistant microbes
  22. Pandemic disease
  23. Solar electro-magnetic bursts (flares)