Question

There has been multiple ice ages on earth. what causes ice ages?

Answer 1

The variation of sunlight reaching Earth is one cause of ice ages. .

Step-by-step explanation:

When less sunlight reaches the northern latitudes, temperatures drop and more water freezes into ice, starting an ice age.

When more sunlight reaches the northern latitudes, temperatures rise, ice sheets melt, and the ice age ends.

Answer 2

The onset of an ice age is related to the Milankovitch cycles - where regular changes in the Earth's tilt and orbit combine to affect which areas on Earth get more or less solar radiation. When all these factors align so the northern hemisphere gets less solar radiation in summer, an ice age can be started.