Natural impacts on the carbon cycle

Question 1

volcanic activity accounts for only ……% of global sources of CO2

Answer 1

0.03 % of global sources of CO2

Question 2

the Earth goes through a climate cycle roughly every…………..

Answer 2

100,000 years

Question 3

a climate cycle is when the Earth’s orbit

Answer 3

the Earth’s orbit changes over 100,000 years where the orbit brings the Earth closer and further away from the sun

Question 4

the process of climate cycles affecting the Earth’s average temperature is called

Answer 4

natural climate change

Question 5

vegetation and the oceans reabsorb …….% of all CO2 emitted by fossil fuel combustion

Answer 5

50%

Question 6

rice paddies produce…..% of all agricultural carbon emissions

Answer 6

10%

Question 7

livestock produces……………% of all agricultural carbon emissions

Answer 7

39%

Question 8

ploughed farmland increases carbon emissions because

Answer 8

• the soil become more aerated due to ploughing, so bacteria colonies grow much quicker and larger thanks to the availability of oxygen
• organic matter in the soil, particularly of previous crops planted there, can be decomposed by the bacteria instead of locked underground and creating a carbon store
• the bacteria then transfer the organic carbon into CO2 which is released into the atnosphere

Question 9

in rice paddies, gaseous carbon compounds are released into the atmosphere because

Answer 9

the anaerobic conditions means methanogenic bacteria colonies decompose organic matter and produce methane

Question 10

deforestation accounts for ………..% of carbon emissions

Answer 10

30%

Question 11

in 20…., cities of population over 500,000 people, accounted for……..% of global carbon emissions

Answer 11

2012

47%