Carbon

Question 1

Fast carbon cycle

Answer 1

Circulates between 10 to 1000 times times faster than the slow carbon cycle

Plants absorb co2 by photosynthesis

Co2 is released back into the atmosphere by plant and animal respiration

Co2 and methane are released back into the atmosphere by decomposition of dead organic matter by microbial activity

Gas exchange occurs between the the atmosphere and the oceans ( atmospheric c02 dissolves in ocean surfaces waters while the oceans ventilate co2 back into the atmosphere through respiration.

Through this, individual carbon atoms are stored in oceans by natural sequestration for 350 years

Fast movement between the soil, vegetation and atmosphere.

Question 2

Slow carbon cycle

Answer 2

Movement of carbon between rock stores, atmosphere and oceans by weathering over millions of years

Carbon is stored in rocks, sea -floor sediments and fossil fuels.

Betweeen 10-100 million tonnes of carbon is circulated by the slow carbon cycle a year.

Weathering of rocks on continents creates a net carbon sink in the oceans

Chemical weathering of rocks by carbonic acid produces carbonate run-off which gets transferred to oceans

Used to make shells on marine organisms such as clams and corals ( fixes carbon with with calcium calcium carbonate)

Organisms die - remains sink to ocean floor

Carbonate sediment produced forms limestone through heat and pressure - held in rocks for 150 million years

Long term carbon store is released to the atmosphere by volcanic eruptions through subduction into the upper mantle by at tectonic plate boundaries.

Question 3

Carbon availability by the natural world and humans

Answer 3

Stores : carbonate rocks ( limestone) ,atmosphere, oceans,see floor sediments and the biosphere

Large molecules are built from carbon molecules eg, proteins,carbohydrates and nucleic acids

Contained in fossil fuels = economic resource powering the global economy and oil used for the manufacture of certain products

Agricultural crops and forest trees, human use of food,timber, textiles

Question 4

Is the carbon cycle open or closed

Answer 4

Global scale = closed with only energy passing the boundary not matter

Local scale = open with materials and energy moving between system boundaries eg, forest ecosystem

Question 5

Atmospheric carbon cycle

Answer 5

Co2 and methane

Methane is a powerful greenhouse gas but is short lived in the atmosphere

Co2 is removed from the atmosphere through terrestrial and oceanic interactions such as photosynthesis and water absorption.

Co2 levels in the atmosphere are the highest they have ever been in 800,000 years

Question 6

Oceanic carbon cycle

Answer 6

Dissolved carbon is held in the ocean water and in the tissues of oceanic organisms

Gas exchange move the inputs and outputs with inputs of organic carbon and and carbonate ions from continental run-off

Large store so any changes in the carbon cycling have large global impacts

Long term carbon store - 38,700 Gt store

Question 7

Use of carbon - flora

Answer 7

Respiration - releases co2 into the atmosphere due to glucose being converted to energy

Photosynthesis - needs co2 to produce glucose

Cycling between atmosphere and biomass

Question 8

Use of carbon - human and animals

Answer 8

Carbon is present in carbs, protein and lipids

Stable molecule to form bonds for living organisms

Carbon based fossil fuels and wood and trees.