1)
W hat causes the long-term changes leading to an ice
age?
Factors that are thought to play important roles in
long-term changes in Earth's climate over millions
or tens of millions of years are
- Changes
in the positions of the continents
- Variations
in the energy output of the sun
- Changes
in atmospheric carbon dioxide concentration
- Changes
in volcanic activity
- Influence
of the biosphere
2) What causes the glacial cycles within an ice age?
During an ice age, the shorter-term cycles of
advancing and retreating glaciers are thought to be
driven by regular, predictable variations in Earth's
orbit and orientation relative to the Sun.