Consider the following statements regarding the natural greenhouse effect:
1. To maintain its long-term thermal equilibrium, the earth must re-radiate back to space the same amount of energy that is absorbed.
2. The re-radiation occurs in the form of thermal short-wave radiation in the infra-red part of the electromagnetic spectrum.
3. The natural greenhouse effect effectively keeps the earth’s surface at least 15℃ warmer than it would otherwise be.
Which of the above statements is/are incorrect?1
1 and 2 only
2
2 and 3 only
3
1 and 3 only
4
All of the above