IB ESS SL 2.3.9 Ocean Carbon Exchange Topic Practice

Complete correct answer:
Net gain in carbon in the oceans:

Inputs to oceans = 92 + 0.8 = 92.8 Pg
Outputs from oceans = 90 + 0.1 = 90.1 Pg

Net gain = 92.8 - 90.1 = 2.7 Pg

Since 1 Pg = 10^15 g, the net gain is 2.7 x 10^15 g.

Marking guidance:
Award 1 mark for 2.7 in units of 10^15 g, with valid use of the Figuredata.

Advantage:
oceans are large so absorb a lot of CO2 / increases primary productivity/photosynthesis / reduces global warming/climate change;

Disadvantage:
increasing $\mathrm{CO}_{2}$ in oceans causes acidification / ocean acidification harms sensitive marine species/ecosystems like coral reefs;