Question

The Karoo Ice Age started about 360 million years ago and lasted for about 40 million years. During this time, less energy entered the Earth system than exited. What is one change to the atmosphere that could have caused this?

a) Carbon dioxide decreased, leading to less energy in the Earth system because less energy was retained by gases and held in the atmosphere.
b) Carbon dioxide decreased, leading to less energy in the Earth system because less incoming energy was reflected back toward Earth.
c) Carbon dioxide increased, leading to more energy in the Earth system because more incoming energy was absorbed and held in the atmosphere.
d) Carbon dioxide increased, leading to less energy in the Earth system because more energy from the sun was reflected back toward outer space.

Answer 1

One change to the atmosphere that could have caused the Karoo Ice Age is a decrease in atmospheric carbon dioxide levels, leading to a diminished greenhouse effect, allowing more heat to escape and cooling the planet.

Step-by-step explanation:

The change to the atmosphere that could have caused less energy to enter the Earth system than exited, leading to the Karoo Ice Age, would be a decrease in carbon dioxide levels. Carbon dioxide decreased, leading to less energy in the Earth system because less energy was retained by gases and held in the atmosphere. This diminishing greenhouse effect resulted in a reduction in heat trapped on Earth's surface, which contributed to the global cooling and the onset of an ice age.

During the Karoo Ice Age, about 360 million years ago, low carbon dioxide levels would have weakened the greenhouse effect, allowing more heat to escape the Earth's atmosphere. This period of reduced greenhouse gases is consistent with geological evidence that suggests lower global temperatures and glaciations.

The role of carbon dioxide in regulating Earth's temperature is well-documented. When atmospheric carbon dioxide is high, it creates a stronger greenhouse effect, trapping more heat and leading to warmer climates. Conversely, when carbon dioxide levels are low, less heat is trapped, and the earth can experience cooling periods severe enough to plunge it into an ice age, as happened during the Karoo Ice Age.