Lesson 3.3.4

3.3.4 How is climate change impacting the ocean system? Quiz: OCR Geography, Unit 7

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

In partnership with Revision Ninja

Lesson 3.3.4, How is climate change impacting the ocean system?: 20 multiple choice questions for the OCR Geography (H481), Unit 7: Exploring Oceans, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. What process occurs when oceans absorb excess atmospheric carbon dioxide, lowering their pH?

    • Coral bleaching
    • Ocean acidification
    • Eutrophication
    • Ocean thermal expansion

  2. How does ocean acidification primarily affect calcifying marine organisms such as corals and molluscs?

    • Weakens calcium shells
    • Boosts photosynthesis rates
    • Increases swimming speed
    • Prevents thermal expansion

  3. What phenomenon occurs when corals expel symbiotic zooxanthellae due to elevated sea surface temperatures?

    • Coral bleaching
    • Ocean stratification
    • Eutrophication
    • Coral calcification

  4. What is the main physical cause of sea level rise resulting from seawater warming?

    • Ocean acidification
    • Thermal expansion
    • Isostatic rebound
    • Enhanced bioaccumulation

  5. Besides thermal expansion, what main process directly adds water volume to the oceans?

    • Submarine volcanism
    • Terrestrial ice melting
    • Deep sea mining
    • Atmospheric condensation

  6. Which feedback mechanism occurs as melting Arctic sea ice exposes darker ocean water?

    • Ocean acidification
    • Positive feedback loop
    • Negative feedback loop
    • Dynamic equilibrium

  7. What term describes a critical point in climate change beyond which environmental changes become irreversible?

    • Ecological threshold
    • Dynamic baseline
    • Carbon sink
    • Thermal equilibrium

  8. What is the primary cause of falling fish stocks linked to ocean chemistry changes?

    • Decreased turbidity
    • Isostatic uplift
    • Ocean acidification
    • Ocean freshening

  9. Which key measure reflects the reflectiveness of sea ice compared to open ocean water?

    • Surface albedo
    • Ocean pH
    • Thermal capacity
    • Salinity gradient

  10. How does sea ice retreat in the Arctic create new economic opportunities for global shipping?

    • Lower water levels
    • Higher wave heights
    • Increased sea ice
    • Shorter shipping routes

  11. Which intergovernmental forum specifically addresses environmental protection and sustainable development in the Arctic region?

    • UN Environment Programme
    • Greenpeace International
    • Arctic Council
    • Antarctic Treaty System

  12. What natural resource discovery is driving geopolitical tension as Arctic ocean ice retreats?

    • Deepwater coral reefs
    • Coastal mangrove forests
    • Atmospheric nitrogen
    • Seabed mineral reserves

  13. How does loss of Arctic sea ice directly impact indigenous coastal communities like the Inuit?

    • Prevents solar radiation
    • Disrupts traditional hunting
    • Causes volcanic eruptions
    • Eliminates ocean tides

  14. What is a common engineering adaptation used by island nations to protect shorelines from rising seas?

    • Hard coastal defences
    • Cloud seeding
    • Deep sea dredging
    • Thermal heating

  15. What term describes the migration of people forced to leave island homes due to sea level rise?

    • Climate displacement
    • Isostatic adjustment
    • Thermal expansion
    • Ocean acidification

  16. Which source of terrestrial freshwater melting contributes most significantly to global ocean volume increase?

    • Floating sea ice
    • Subterranean aquifers
    • River discharge
    • Continental ice sheets

  17. What impact does ocean warming have on local communities heavily dependent on coral reef ecotourism?

    • Severe economic loss
    • Expansion of mangroves
    • Increased fish harvests
    • Enhanced beach formation

  18. What happens to the concentration of hydrogen ions in seawater as ocean acidification progresses?

    • Hydrogen ions increase
    • Hydrogen ions freeze
    • Hydrogen ions decrease
    • Hydrogen ions disappear

  19. Why does melting floating sea ice NOT contribute directly to sea level rise?

    • Sea ice dense
    • Ice contains salt
    • Open ocean freezes
    • Water already displaced

  20. What geopolitical challenge arises as receding Arctic ice opens international waters to resource extraction?

    • Overlapping territorial claims
    • Reduced global trade
    • Decreased maritime transport
    • Complete demilitarisation

All OCR Geography quizzes