carbon cycle

Question 1

what are the linkages in the inorganic carbon cycle?

Answer 1

• volcanism
• solubility pump
• chemical weathering
• subduction

Question 2

what are the reservoirs in the inorganic carbon cycle?

Answer 2

• oceans
• atmosphere
• rocks

Question 3

what is volcanism?

Answer 3

melting rocks as a result of intense heat from the interior of the planet that rise towards the surface, reach the crust and emerging into the atmosphere

Question 4

how is volcanism a part of the carbon cycle?

Answer 4

• carbonate rocks release CO2 when broken down
• CO2 gas is released along with heat and melted minerals during volcanic activity

Question 5

what is the solubility pump?

Answer 5

the direct exchange of carbon between the atmosphere and the ocean

Question 6

what happens when CO2 enters the ocean?

Answer 6

1. CO2 dissolves in water
2. reacts with water to create carbonic acid
3. carbonic acid can turn into bicarbonate
4. bicarbonate can turn into carbonate

• all these reactions are reversible

Question 7

what are the steps in chemical weathering?

Answer 7

1. CO2 reacts with H2O in the atmosphere -> carbonic acid
2. carbonic acid falls with rainwater
3. reacts with exposed sedimentary rock
4. results in the production of calcium ions and bicarbonate ions
5. rainfall washes bicarbonate/calcium ions into the ocean
6. calcium ions and carbonate ions combine in solution to form calcium carbonate
7. calcium carbonate is used by shell-producing life forms
8. calcium carbonate settles on the ocean floor
9. forms mineral deposits of calcium carbonate

Question 8

what is subduction?

Answer 8

when one tectonic plate is pushed under another -> the plate being subducted eventually melts as a result of the heat in the interior of the planet

Question 9

how does subduction contribute to the carbon cycle?

Answer 9

carbonate rocks from the ocean deposits melt during subduction and convert to CO2 gasses

Question 10

what are the linkages in the organic carbon cycle?

Answer 10

• photosynthesis
• decomposition
• cellular respiration
• fossil fuels
• biological pump
• anthropocentric linkages

Question 11

what is humus?

Answer 11

the organic component of the soil composed of partially decomposed organic molecules

Question 12

what are fossil fuels?

Answer 12

reservoirs of concentrated carbon formed in the ancient geological past from the remains of plant and animal life that did not fully decompose

Question 13

what are the steps to fossil fuel formation?

Answer 13

1. dead organic matter buried by sedimentation before it can be fully decomposed
2. increasing build up of sediments
3. increasing weight compressing organic matter moving it deeper in the crust
4. increasing compression and heat which removes trapped water and gases and transforms larger carbon molecules to smaller ones
5. concentrated carbon remains

Question 14

what happens in the biological pump?

Answer 14

photosynthesis, cellular respiration, decomposition and fossil fuel formation in the marine habitats

Question 15

how do calcium carbonate deposits get back on land?

Answer 15

through tectonic plate movement

Question 16

why are there seasonal fluctuations in the carbon cycle?

Answer 16

because photosynthetic rates increase in the spring/summer, taking up carbon diozide and then plant growth slows down in fall/winter so cellular respiration becomes the primary process involving carbon dioxide

Question 17

what are the three major anthropogenic linkages in the carbon cycle?

Answer 17

• burning of fossil fuels for energy
• changing land use
• creating concrete from limestone

Question 18

what is the concequence of ocean acidification on shell formation?

Answer 18

• the increasing H+ ions in the ocean bind with the available carbonate making bicarbonate
• this removes the reservoir of dissolved carbonate for the formation of calcium carbonate
• because H+ has higher affinity to carbonate than calcium, existing molecules of calcium carbonate can break appart and shells can dissolve at a low pH

Question 19

what is the Greening Hypothesis?

Answer 19

carbon dioxide is a fertilizer and when increased, it will stimulate greater plant productivity and expand forests

Question 20

what is a FACE system?

Answer 20

Free Air Carbon Dioxide Enrichment system
- large scale experimental exposure of plants in real world conditions to elevated atmospheric carbon dioxide levels

Question 21

what are the results of the FACE experiment?

Answer 21

plants love the CO2 at first exposure and then eventually they run into other limitations
- there are other climatic stressors from climate change that dramatically modify the relationship between increase CO2 and plant growth (like drought and nutrient deficiencies)

Question 22

what is the Junk Food Effect?

Answer 22

increased sugar production in plants results in decrease in production of other organic molecules and reduction in mineral uptake
- cells only have a finite amount of space!