Why do ice ages occur?

Related questions

1. How much of the Earth was covered in the last ice age?
2. How often do ice ages occur?
3. When was the last ice age on Earth?
4. How did humans survive during the ice age?
5. How did the ice age affect humans?
6. Do humans share 50 DNA with bananas?
7. Can an ice age happen again?
8. Are Sharks older than dinosaurs?
9. What are the 5 major ice ages?
10. Can a volcano cause an ice age?

Tags

1. #solar
2. #which
3. #onset
4. #areas
5. #where
6. #these
7. #northern
8. #combine
9. #hemisphere
10. #earth
11. #affect
12. #cycles
13. #factors
14. #started
15. #regular
16. #milankovitch
17. #align
18. #related
19. #summer
20. #radiation
21. #changes
22. #orbit