Climate Change (HL IB Biology)

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).

Outline the impacts of increasing average global temperatures.

Methane 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.

Suggest a reason why wetlands would be the largest contributor of atmospheric methane, as shown in the graph above.

Carbon 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.

Suggest possible causes of the trends in the data presented in part (a).

Discuss the importance of greenhouse gases, such as carbon dioxide, in the atmosphere.

One 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.