Processes Of The Carbon Cycle

Question 1

Photosynthesis

Answer 1

The flux of carbon from atmosphere to land plants and phtoplankton averages 120 GT per yr.
Equation:6CO2 + 6H2O➡️C6H12O6 + 6O2
(Uses solar energy)

Question 2

Acid rain

Answer 2

Atmospheric CO2 dissolves rainwater to for weak carbonic acid.
Rising concentrations of atmospheric CO2 due to emissions have increased acidity of rainfall and therefore ocean waters. This has harmful effects on marine life.

Question 3

Weathering

Answer 3

The in situ breakdown of rocks at or near the Earth’s surface by chemical, biological and physical processes
Carbonation equation: CaCO3 + H2CO3➡️ Ca(HCO3)2
Calcium carbonate and carbonic acid makes calcium bicarbonate

Question 4

Chemical weathering and example of solution weathering

Answer 4

Transfers 0.3 billion tonnes of carbon to oceans and atmosphere per yr

At norber brow in Yorkshire dales, the limestone surface has been lowered by half a metre over 13 000 yrs

Question 5

Biological weathering

Answer 5

Chelation also contributes to rock breakdown

Question 6

Respiration

Answer 6

Equation: glucose + oxygen➡️carbon dioxide and water

The volume of carbon exchanged by this and photosynthesis each year is 1000 times greater thsn that moving through the slow carbon cycle

Question 7

Decomposition

Answer 7

Bacteria and fungi breakdown dead organic matter which releases CO2.
Rates depend on climatic conditions with faster rates occuring in warmer, humid climates like tropical rainforest

Question 8

Combustion

Answer 8

Combustion is a natural fuel e.g. wildfires caused by lightning are essential to the health of some ecosystems

Combustion of fossil fuels transfers 10GT of CO2 a yr from geological store to oceans, biosphere etc.