Syllabus Edition
First teaching 2023
First exams 2025
7 marksIncreased carbon dioxide levels in the atmosphere are having an effect on ocean chemistry.
Outline the way in which atmospheric carbon dioxide affects the pH of oceans and how this change may impact marine organisms.
1 markDefine the term carbon sequestration in the field of climate science.
Did this page help you?
Outline the relevance of increasing atmospheric carbon dioxide levels to the results shown in part (a).
Describe a process that removes carbon dioxide from the atmosphere other than that referred to in part (b).
Did this page help you?
2 marksMethane is an example of a greenhouse gas that commonly occurs in the atmosphere. The graph below shows the main sources of methane as well as the percentage contribution of the different components of each source. A teragram (Tg) equals 1012 grams and is equivalent to one megatonne (1 million tonnes).
Calculate the amount of methane, in Tg year-1, that is released from wetlands. Show your working.
2 marksSuggest a reason why wetlands would be the largest contributor of atmospheric methane, as shown in the graph above.
Did this page help you?
3 marksCarbon dioxide is one of the main greenhouse gases in the atmosphere. The graph below shows the changes of carbon dioxide levels in the atmosphere, as well as the change in global temperatures over a period of time.
Describe the general trends in the data.
2 marksSuggest possible causes of the trends in the data presented in part (a).
2 marksDiscuss the importance of greenhouse gases, such as carbon dioxide, in the atmosphere.
Did this page help you?
3 marksOne mark is available for clarity of communication throughout this question.
Suggest the possible impact that an increase in global temperatures would have on the polar regions, as well as the global consequences of this impact.
Did this page help you?
The image below shows two shells from marine organisms. Both shells were placed in a saltwater solution for 45 days; shell A at pH 8.5 and shell B at a pH of 7.
Explain the results shown in the image.
Outline the relevance of increasing atmospheric carbon dioxide levels to the results shown in part (a).
Describe a process that removes carbon dioxide from the atmosphere other than that referred to in part (b).
Did this page help you?
Outline the impacts of increasing average global temperatures.
Did this page help you?