| Date | May 2015 | Marks available | 1 | Reference code | 15M.1.HL.TZ1.16 |
| Level | Higher level | Paper | Paper 1 | Time zone | Time zone 1 |
| Command term | Define | Question number | 16 | Adapted from | N/A |
Question
What is the best definition of the greenhouse effect in the Earth’s atmosphere?
A. A naturally occurring effect by which shorter wavelength radiation is trapped
B. A naturally occurring effect by which longer wavelength radiation is trapped
C. An effect of pollution by which shorter wavelength radiation is trapped
D. An effect of pollution by which longer wavelength radiation is trapped
Markscheme
B
Examiners report
This was answered correctly by only a third of candidates, and the distribution of wrong answers revealed two popular misconceptions. The first is that the greenhouse effect is caused by pollution, when the teacher’s notes for assessment statement 5.2.3 state that it is a natural phenomenon that is merely enhanced by the emissions of greenhouse gases. The second misconception was that it is shorter wave radiation that is trapped in the atmosphere. The same teacher's note states that students should be aware that it is longer wave radiation that is trapped.
