1.A.5 - The Carbon Cycle

Question 1

What is carbon found in?

Answer 1

• All life forms
• Sedimentary rocks
• Diamonds
• Graphite
• Coal
• Petroleum (oil and natural gas)

Question 2

What is organic carbon?

Answer 2

The form found in living organisms such as plants and trees.

Question 3

What is inorganic carbon?

Answer 3

The form found in non-living organisms such as ores and minerals

Question 4

What is stored in the bonds between atoms in molecules containing carbon?

Answer 4

Chemical energy needed for life

Question 5

Carbon dioxide’s formula and description

Answer 5

CO2 - A gas found in the atmosphere, soils, oceans and sedimentary rocks

Question 6

Methane’s formula and description

Answer 6

CH4 - A gas found in the atmosphere, soils and oceans

Question 7

Calcium Carbonate’s formula and description

Answer 7

CaCO3 - A solid found in calcareous rocks, oceans and skeleton and shells or ocean creatures

Question 8

Description of Hydrocarbons

Answer 8

Solids, liquids and gases usually found in sedimentary rocks

Question 9

Description of Bio-molecules

Answer 9

Complex carbon compounds produced in living things. E.g proteins, carbohydrates, fats & oils and DNA.

Question 10

Why do geographers study CO2 in most detail? 1/3

Answer 10

CO2 has a profound effect on climate. By volume it’s a very significant greenhouse gas.

Question 11

Why do geographers study CO2 in most detail? 2/3

Answer 11

It is difficult to separate a natural carbon cycle from one that is affected by human activity. Earth has a completely natural GHG effect but humans are affecting it.

Question 12

Why do geographers study CO2 in most detail? 3/3

Answer 12

Anthropogenic CO2 emissions fundamentally affect the carbon cycle so affect climate. Humans are transferring carbon from the lithosphere to the atmosphere faster than ever in Earth history.

Question 13

Where did CO2 originate from?

Answer 13

Stored in the mantle when the Earth formed

Question 14

Where does the carbon escape from inside the Earth?

Answer 14

At constructive and destructive plate boundaries as well as hot-spot volcanoes

Question 15

What kind of rock is the carbon released back into the atmosphere from at destructive plate boundaries?

Answer 15

Carbonate rocks subducting with the ocean crust

Question 16

Where do we find other carbon?

Answer 16

• Some is dissolved in oceans
• Some carbon held as biomass in living or dead and decaying organisms
• Some bound in carbonate rocks

Question 17

Where and how is carbon removed into long-term carbon?

Answer 17

Burial of sedimentary rock layers, especially coal and black shales and carbonate rocks like limestone.

Question 18

Describe how the carbon stored in plants and animals living in the oceans get transferred to the lithosphere

Answer 18

When organisms die, their dead cells, shells and other parts sink into deep water. Decay releases carbon dioxide into this deep water. Some material sinks right to the bottom, where it forms layers of carbon-rich sediments. Over millions of years, chemical and physical processes may turn these sediments into rocks.

Question 19

What is humus?

Answer 19

Thick brown or black substance that remains after most of the organic litter has decomposed

Question 20

What role do animals play in the carbon cycle?

Answer 20

Very important in the generation of movement of carbon in the carbon cycle

Question 21

What impact has human activity had on levels of carbon in the atmosphere?

Answer 21

It is higher than it has been for at least 800,000 years

Question 22

Why is Carbon Dioxide important?

Answer 22

It is a potent greenhouse gas and pays a vital role in regulating the Earth’s surface temperature

Question 23

What is the name of the graph that shows change in levels of atmospheric CO2?

Answer 23

Keeling curve