Factors causing long term change to the carbon cycle

Question 1

Natural activity

Answer 1

Volcanic activity

Wildfires

Question 2

Volcanic activity

Answer 2

Expulsion of CO2 and GHG into the atmosphere
380 million tonnes of CO2 emitted by volcanoes
30 billion tonnes of CO2 emitted by human activity

Warming effect of CO2 counterbalanced by action of sulphur dioxide that - when converted to sulphuric acid - increases reflection of the sun, cooling the Earth’s atmosphere

Question 3

Wildfires

Answer 3

Releases biological terrestrial carbon from carbon sinks

Victoria case study: (2009)
330m2 tonnes of CO2

Question 4

Human activities

Answer 4

Fossil fuel combustion
Cement manefacture
Farming practices
Deforestation
Urban growth

Question 5

Fossil fuel combustion

Answer 5

90% CO2 release comes from combustion of fossil fuels
Vegetation and ocean reabsorb 50% of this
CO2 levels have risen by 80ppm in the last 50 years

Question 6

Cement manefacture

Answer 6

Produces 5% of all human-induced global CO2 emissions

For every 1000kg of cement produced, 900kg of CO2 is released

Question 7

Farming practices

Answer 7

Enteric fermentation (methane from digestion from livestock) - 39% of all agricultural emissions
Rice paddies generate 10% of CO2 emissions
Burning tropical grassland
More population = more demand
Slash and burn techniques
Soil ploughing leads to increased CO2
Tractors

Question 8

Deforestation

Answer 8

Driven by need for agricultural land
Lose 600 million metric tonnes of stored CO2 per year
13 million hectares/ year
Logging needs
Help maintains the water cycle

Question 9

Urban growth

Answer 9

Increased pop. in urban areas
CO2 from transport, industry, domestic use, and cement
In 2012 - 47% of all CO2 emissions
Concentrated around cities