1. Oil running out
1.1. fuel shortage
1.1.1. messier extraction methods of e.g. oil tar sands
1.1.2. likely to lead to armed conflict due to military prioritization of fuel acquisition
1.1.3. rising prices of consumer goods (due to increased shipping prices)
1.1.4. increased dependence on bio-fuels, taking away nourishment that could be used to combat famine.
1.2. likely to increase dependency on other fossile fuels (as long as a viable full-scale alternative is not found)
2. Ressources running out
2.1. oil = affects our plastics dependency
2.2. rare minerals / metals, e.g. computer industry
2.3. food ressources, e.g. fishing stocks
3. Plastics pollution of the oceans
3.1. "The Great Pacific Gyre"
3.2. Wide-spread pollution of our oceans is a reality
3.3. risk of destroying vital part of the global food chain
4. Economy
4.1. based on perpetual expansion
4.1.1. impossible due to dwindling resources
4.1.2. impossible due to existing production methods, carbon emission problems et.al.
4.1.3. a "virtual" construct, based largely on the perception of value, rather than actual value.
4.2. market economy problems
5. Climate change
5.1. temperature increase
5.1.1. impact on food chain
5.1.2. famine
5.1.3. destruction of fragile eco systems
5.1.3.1. coral reefs
5.1.3.2. arctic-based species, e.g. krill, shrimp
5.1.4. melting of glaciers
5.1.4.1. disruption of natural water flow
5.1.4.2. removal of vital water supply (e.g. in the Himalayas)
5.2. melting of polar ice
5.2.1. sea levels rising
5.2.1.1. civil unrest
5.2.1.2. refugee problems
5.2.2. release of gasses tied up in the ice
6. Population growth
6.1. increased demands on infrastructure
6.2. famine
6.3. demands for higher quality of life for vast amounts of people
6.4. slanted, high population growth in some areas, low in others, leading to some countries having too many old people. A system that's based on perpetual expansion crumbles when new influx of people is much smaller than the existing population base, which needs sustaining.
7. Political extremism
7.1. fascism on the rise in Europe / US
7.1.1. restrictive legislation
7.1.2. fewer civil rights
7.1.3. more control (police/legal)
7.1.4. increased media control by the gov't
7.1.5. removal of influence from ordinary citizens
7.1.6. leaders not always elected, chosen instead (example: the EU / religious edicts in e.g. Iran)
7.1.7. fewer public elections, e.g. expansion of the EU (EU president, military, economic)
7.2. extremism
7.2.1. Islamic countries political/religious melding
7.2.2. US political/religious melding
7.2.3. atheist increasingly organized / firm stance