Carbon cycle

Question 1

early history of CO2

Answer 1

• carbon atoms part of earths early formation from ancient star
• volcanoes first introduced CO2 into atmosphere
• co2 reacted chemically with rock to create limestone and released back into atmosphere
• cycle sped up 3.5bya as photosynthetic microorganisms converted
  CO2 into organic compounds and respired and released CO2
  back into the atmosphere

Question 2

Charles Kedwig

Answer 2

• started to monitor CO2 atmospheric concentration in Mauna Loa, Hawaii
• hypothesis of increaser in co2 proven by early data
• monitored there currently by infra red gas analyser
• 315-404ppm 1958-2015

Question 3

variations in CO2 inputs

Answer 3

• geological, volcanoes, mid-ocean ridges
• biological, respiration
• human, deforestation, burning fossil fuels

Question 4

CO2 removal

Answer 4

• geological, weathering of silica rocks
• biological, photosynthesis

Question 5

green carbon

Answer 5

terrestrial vegetation and soils

Question 6

blue carbon

Answer 6

marine vegetated habitats and sediments

Question 7

brown carbon

Answer 7

GHG emissions

Question 8

black carbon

Answer 8

emissions as a result of imperfect combustion e.g. soot and dust from wood burners and diesel card

Question 9

evidence of rise in CO2

Answer 9

• change in isotope ratios and gas bubbles trapped in ice cores
• matches with increase in industrialisation

Question 10

global carbon cycle stores

Answer 10

• marine and terrestrial
• short and long term

Question 11

long term carbon cycle

Answer 11

• driven by geological processes
• volcanoes, CO2, global dimming
• silicate erosion
• subduction, CaCO3 into mantle
• carbonate weathering
• sedimentation

Question 12

decomposition

Answer 12

• breakdown of organic materials
• bacteria and fungi
• detritivores

Question 13

arctic soil

Answer 13

• holds 1/3 of soil carbon
• plants are deep rooted to survive exposed conditions so store most biomass underground
• peat stores lots of carbon
• cold and dry, slow rate of decomposition
• threatened by arctic amplification

Question 14

tropical rainforests

Answer 14

• shallow soils
• most biomass above ground
• dramatic rates of photosynthesis
• deforestation creates localised drought
• effective at sequestering carbon
• can be regenerated relatively quickly

Question 15

marine systems

Answer 15

• > 50% CO2 captured by marine autotrophs (phytoplankton in sea and macrophytes at coast) and absorbed by sea
• threatened by ocean acidification and warming