Today, scientists believe that the main reason the Earth has had periodic ice ages is:
A) slow changes in the tilt of our planet's axis of rotation
B) the grinding of continental plates against each other over the centuries
C) changes in the composition of the Earth's atmosphere that affect the ozone layer
D) the fact that the Moon is slowly moving toward the Earth and drawing off heat
E) no one has any good theories about the cause of the ice ages
Section 8.4: Life, Chemical Evolution, and Climate Change

Question

Quizplus · Accepted Answer

Slow changes in the tilt of our planet's axis of rotation are believed to be the main reason for Earth's periodic ice ages. This tilt changes over tens of thousands of years, causing variations in the amount of sunlight that different parts of the Earth receive, which can ultimately affect global climate patterns.

Today, Scientists Believe That the Main Reason the Earth Has