Question

What initiated the runaway greenhouse effect on Venus?

A) Venus slowly got closer to the Sun.

B) The Iack of plant life on Venus

C) The gradual warming of the Sun

D) The Iack of water vapor on Venus

Answer 1

The runaway greenhouse effect on Venus was initiated by a gradual increase in the energy output of the Sun, which caused increased evaporation of water from the oceans and the release of gas from surface rocks. This led to an amplification of the greenhouse effect and a continued rise in temperature.

Step-by-step explanation:

The runaway greenhouse effect on Venus was initiated by a gradual increase in the energy output of the Sun. Venus may have once had a climate similar to that of Earth, with moderate temperatures and water oceans. However, as the Sun's energy output increased, even a small amount of extra heat caused increased evaporation of water from the oceans and the release of gas from surface rocks. This led to a further increase in the atmospheric CO₂ and H₂O, amplifying the greenhouse effect and causing the temperature to continue rising. This process is known as the runaway greenhouse effect.

Answer 2

The runaway greenhouse effect on Venus was initiated by modest additional heating due to a gradual increase in the Sun's energy output, leading to the release of greenhouse gases and a cycle of increasing temperatures. So the correct option is C.

Step-by-step explanation:

The runaway greenhouse effect on Venus was not initiated by Venus slowly getting closer to the Sun, the lack of plant life, or the lack of water vapor. It was triggered by a modest additional heating from a gradual increase in the energy output of the Sun. This small amount of extra heat could have led to increased evaporation of water from the oceans, if they existed on Venus and the release of gases like CO2 from surface rocks. This, in turn, caused an increase in atmospheric CO2 and H2O, which are gases that amplify the greenhouse effect. Once this cycle began, the temperature kept rising without any processes in place to offset it, leading to the current inhospitable conditions on Venus.