DP Biology (first assessment 2025)
Question 23M.2.SL.TZ2.c
Date | May 2023 | Marks available | [Maximum mark: 7] | Reference code | 23M.2.SL.TZ2.c |
Level | SL | Paper | 2 | Time zone | TZ2 |
Command term | Describe | Question number | c | Adapted from | N/A |
c.
[Maximum mark: 7]
23M.2.SL.TZ2.c
Describe how human activities have caused average surface air temperatures on Earth to increase.
[7]
Markscheme
- release of carbon dioxide;
- combustion of fossil fuels produces carbon dioxide;
- forest fires (caused by humans) produce carbon dioxide;
- deforestation reduces carbon dioxide uptake by photosynthesis;
- release of methane;
- from cattle/sheep/ruminant digestive systems / other verified source of anthropogenic methane;
- greenhouse effect / carbon dioxide/methane is a greenhouse gas;
- carbon dioxide/methane allow short wave radiation in sunlight to pass through the atmosphere;
- longer wave/infra-red radiation emitted by the warmed Earth’s surface;
- carbon dioxide/methane absorbs/reflects back longer wave/infra-red radiation;

