Answer:
As temperatures decrease, less sunlight reaches the water. This causes the ice to freeze, when this happens in mass it causes an ice age. Later, temperatures rise and the ice melts.
Step-by-step explanation:
Temperatures plummet as less sunlight reaches northern latitudes, and more water freezes into ice, triggering an ice age. Temperatures rise, ice sheets melt, and the ice age ends as more sunshine reaches northern latitudes.