Question

based on the information above, which of the following statements are true? select all that apply.

1. earths average temperature is warmer than it would be if earths atmosphere did not contain any greenhouse gases.
2. after infrared radiation is trapped in the atmosphere, the infrared radiation may be absorbed by other greenhouse gas molecules.
3. greenhouse gas molecules gain energy after absorbing infrared radiation.
4. greenhouse gas molecules absorb but not release infrared radiation.

Explanation:

1. The greenhouse effect warms Earth's surface by trapping infrared radiation; without greenhouse gases, more heat would escape to space, making the planet colder.
2. Trapped infrared radiation in the atmosphere can be absorbed multiple times by different greenhouse gas molecules as it moves.
3. When greenhouse gas molecules absorb infrared radiation, they take in the energy of the radiation, increasing their own internal energy.
4. Greenhouse gas molecules re-emit infrared radiation after absorbing it (some back toward Earth, contributing to the warming effect), so this statement is false.

Answer:

• Earth's average temperature is warmer than it would be if Earth's atmosphere did not contain any greenhouse gases.
• After infrared radiation is trapped in the atmosphere, the infrared radiation may be absorbed by other greenhouse gas molecules.
• Greenhouse gas molecules gain energy after absorbing infrared radiation.