Question 18M.3.sl.TZ2.b
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.3.sl.TZ2.b |
| Level | sl | Paper | 3 | Time zone | TZ2 |
| Command term | Discuss | Question number | b | Adapted from | N/A |
Carbon dioxide is a product of the combustion of petrol.
Discuss the significance of two greenhouse gases, other than carbon dioxide, in causing global warming or climate change.
[2]
Any two of:
H2O AND «relatively» greater abundance/stable concentration/less effective at absorbing radiation/lower GWP so not much overall effect on global warming/climate change
CH4/N2O/CFCs/SF6/O3/HCFCs AND more effective «than CO2» at absorbing radiation/higher GWP so could contribute to global warming/climate change
PFCs/SF6/NF3/Some CFCs AND have very long life in atmosphere so could contribute «in the future» to global warming/climate change
Accept names or formulas.
Accept two different gases with the same effect for [2].
Award [1 max] for identifying the names/formulas of two greenhouse gases.
Accept “greenhouse factor” for “GWP” but not just “greenhouse effect”.
For M3, do not allow “CFC” alone as only some have long lifetimes (eg, CFC-115, CFC-113).
[2 marks]
