The processes in the carbon cycle - carbon exchange

Question 1

What are the main processes involved in carbon exchange

Answer 1

Precipitation
Photosynthesis
Weathering
Respiration
Decomposition
Combustion

Question 2

How is precipitation involved in the carbon cycle

Answer 2

Atmospheric C02 dissolves in rainwater to form weak carbonic acid
Human activities are increasing the acidity of rainfall resulting in ocean surface waters becoming more acidic

Question 3

How is photosynthesis involved in the carbon cycle

Answer 3

The flux of carbon from atmosphere to land plants and phytoplankton via photosynthesis averages around 120 gigatonnes
CO2 is used in photosynthesis

Question 4

What is weathering

Answer 4

In situ breakdown of rocks at or near the surface

Chemical, biological and physical processes

Question 5

Explain chemical weathering

Answer 5

Most weathering involves rainwater which contains dissolved CO2
This dissolves carbonate rocks
Transfers carbon to the atmosphere, streams, rivers and the ocean

Question 6

Explain physical weathering

Answer 6

Freeze-thaw breaks rocks donw into smaller particles but involves no chemical weathering
This process increases the surface area exposed to chemical processes