6.2a

Question 1

How does thebiolgical pump work?

Answer 1

1. Phytoplankton sequester carbon through photosynthesis. Phytoplankton are microorganisms that live near the surfce of the ocean, their huge population makes up half the world’s biomass
2. When they are eaten the carbon they absorbed is released by the consumer through respiration or digestion
3. However 0.1% of them die and end up on the sea floor where they either decompose or turn into sediment
4. Phytoplankton sequester 2 billion tones of CO2 annually

Question 2

How does the cabonate pump work?

Answer 2

• Marine organisms build shells from calcium carbonate (CaCO3). When the organisms die the shells dissolve as they sink and become part of deep ocean currents.
• Shells that don’t dissolve build up slowly on the seafloor forming limestone over a long period of time.

Question 3

How does the Physical pump work?

Answer 3

• Colder the water the more CO2 can be absorbed into the ocean. This means that polar water can hold upto double the carbon tropical water can.
• Ocean currents take water to the poles where it is colder meaning more carbon is absorbed. As the surface water cools it sinks taking the carbon it absorbed with it.