IB ESS HL 2.3.10 Ocean Acidification Topic Practice

a. $\mathrm{CO}_{2} /$ greenhouse gas emissions lead to increasing global/atmospheric temperatures;
b. higher levels of atmospheric $\mathrm{CO}_{2}$ lead to more $\mathrm{CO}_{2}$ dissolved in ocean water…;
c. ...which leads to ocean acidification / reduced pH;
d. increased global temperatures cause rise in ocean temperature...;
e. ...also cause expansion/increase in volume of ocean/rising sea levels (same MP if linked to melting of glaciers MPg);
f. ...also may increase algal growth, which absorbs more sunlight / making water even warmer / increasing oxygen availability in water (locally);
g. ...also cause melting of ice caps/glaciers...;
h. ... which, in turn, dilutes salinity of surrounding sea;
i. rising sea temperatures reduce solubility of gases/available oxygen [no contradiction with local impact in MPf];
j. changing salinity/temperatures will cause changes in ocean currents/conveyor belt;
k. oil spills may cause pollution/reduce light penetration...;
I. ...regionally reduced light penetration/killing of phytoplankton results in reduced oxygen levels (due to reduced photosynthesis) [no contradiction with local impact in MPf];
m. changing weather patterns/events may affect wind-driven oceanic currents;
n. lower pH may cause death of sea life (e.g. coral) which will decompose (aerobically), thus increasing $\mathrm{CO}_{2}$ in oceans / or decompose anaerobically in deep ocean, thus increasing $\mathrm{CH}_{4}$;
o. Increased GHGs/temperature may increase ocean evaporation leading to loss of water / increased salinity;

Note: Do not credit mention of acid rain, NOx, SO2 emissions affecting ocean pH. Do not credit use of oil in manufacturing petrochemicals (e.g. plastics) Credit may be given for any other valid responses linking fossil fuel use to some abiotic change in oceans.