Carbon cycle Exchanges

Question 1

Precipitation

Answer 1

Atmospheric CO2 dissolves in rainwater to form weak carbonic acid.

Carbonic acid levels are increasing due to increased combustion - leads to acid rain.

Question 2

Photosynthesis

Answer 2

The flux of carbon from the atmosphere to land plants and phytoplankton via photosynthesis averages 120 gigatonnes a year.

Question 3

Weathering

Answer 3

Breakdown of rocks at or near the earths surface, via chemical, physical or biological processes.

Question 4

Respiration

Answer 4

The opposite of photosynthesis.

Respiration is the process which carbohydrates are converted to co2 + water.

Question 5

Decomposition

Answer 5

Bacteria and Fungi breakdown dead organic matter, extracting energy and releasing CO2 into the atmosphere and minerals into the soil.

Question 6

Combustion

Answer 6

Organic material is burnt in the presence of oxygen. The combustion process releases CO2 + other gases into the atmosphere.

Question 7

Fast carbon cycling spheres

Answer 7

Pedoshpere
Atmosphere
Biosphere
Hydrosphere

Question 8

Slow carbon cycling spheres

Answer 8

Cryosphere

Lithosphere

Question 9

Biological organic pumps

Answer 9

CO2 absorbed by phytoplankton, which is absorbed into zooplankton, which are eaten by fish - This fixes carbon from the atmosphere into the hydrosphere.

Question 10

Physical organic pumps

Answer 10

Downwelling:
The absorption of co2 into the ocean in colder temperatures / salinated water.

Upwelling:
The release of co2 from oceans in warmer temperatures.

These pumps affects the THC + cause positive feedback mechanism

Question 11

Thermohaline circulation