1. Carbon Cycle

2. Atmosphere
Biosphere
Hydrosphere
Lithosphere

3. Carbon Cycle
a description of how carbon is moving through Earth’s Systems
this movement of carbon includes living things as carbon-based molecules provide the basis for the structure of every living thing

4. Earth’s Systems
just like in the water cycle, Earth’s systems serve as temporary stores of carbon until is moves on to a new system
Hydrosphere
Lithosphere
Biosphere
Atmosphere

5. Earth Systems

6. Atmosphere
Biosphere
Hydrosphere
Lithosphere

7. 1. Hydrosphere
Earth’s surface water can primarily store carbon in the form of carbonic acid (H2CO3)
when carbonic acid levels get high, the pH of the water drops

8. 1. Hydrosphere
In a lab experiment, a sea butterfly (pteropod) shell placed in seawater with increased acidity slowly dissolves over 45 days.
Credit: Courtesy of David Littschwager/National Geographic Society

9. 1. Hydrosphere
Low pH levels kill coral. Coral provide habitats for many other ocean-dwelling species.

10. 2. Lithosphere
many of Earth’s sedimentary rocks have large amounts of carbon

11. 2. Lithosphere
fossil fuels buried in the Earth also contain large amounts of carbon

12. 3. Biosphere all living things are made of molecules made of carbon
recently dead living things also make up the soil on the surface of the earth

13. 4. Atmosphere
most of the carbon in the air is in the form of carbon dioxide (CO2)

14. 4. Atmosphere
carbon dioxide levels have been steadily increasing due to increased combustion of fossil fuels

15. 4. Atmosphere
Graph of atmospheric carbon dioxide concentration vs. mean global temperature during the past 1,000 years.

16. Which system stores the most carbon?
Reservoir
Amount of Carbon
(gigatons)
Atmosphere
720
Oceans (total)
38,400
Surface ocean layer
670
Deep ocean layer
36,730
Lithosphere
75,004,130
Rocks
75,000,000
Fossil fuels (total)
4,130
Coal
3,510
Oil
230
Gas
140
Peat
250
Biosphere
2,002
Land biosphere (total)
2,000
Living biomass
800
Dead biomass
1,200
Aquatic biosphere 2
Lithosphere
Hydrosphere
Biosphere
Atmosphere

17. Atmosphere
Biosphere
Hydrosphere
Lithosphere

18. Carbon Transition Processes
carbon has many ways of moving between earth’s systems
there is no specific order to this movement
Burning
CO2 Exchange
Decay
Deep circulation
Extraction
Organic Consumption
Photosynthesis
Respiration
Rock formation
Run-off

19. Atmosphere
Biosphere
Hydrosphere
Lithosphere

20. 1. Burning
when organic materials burn, carbon dioxide is released into the air
Examples of organic materials include wood and fossil fuels

21. Atmosphere
Biosphere
Hydrosphere
Lithosphere

22. 2. Carbon Dioxide Exchange
when CO2 levels increase in the air, more CO2 will dissolve into the ocean
when CO2 levels decrease in the air, more CO2 will dissolve out of the ocean

23. 4. Atmosphere
Carbon dioxide levels have been steadily increasing due to increased combustion of fossil fuels

24. 2. Carbon Dioxide Exchange
when CO2 levels increase in the air, more CO2 will dissolve into the ocean
when CO2 levels decrease in the air, more CO2 will dissolve out of the ocean
when carbon dioxide dissolves in water it forms carbonic acid

25. Atmosphere
Biosphere
Hydrosphere
Lithosphere

26. 3. Decay
when living things die, their tissues become a part of the soil
as their tissues continue to breakdown, some of the carbon is released as CO2 into the air
methane (CH4) is also released but in much smaller amounts than CO2

27. 4. Deep Circulation
some carbon from phytoplankton sinks into deep ocean currents and might not return to the surface for hundreds of years

28. 4. Deep Circulation
some carbon from phytoplankton is carried into deep ocean currents and might not return to the surface for hundreds of years
phytoplankton – small, plant-like organisms

29. Atmosphere
Biosphere
Hydrosphere
Lithosphere

30. 5. Extraction bringing buried fossil fuels to the surface
most fossil fuels have been buried for millions of years

31. Atmosphere
Biosphere
Hydrosphere
Lithosphere

32. 6. Organic Consumption
when one organism consumes (eats) another organism, carbon remains in the biosphere

33. Atmosphere
Biosphere
Hydrosphere
Lithosphere

34. 7. Photosynthesis
plants, some protists, and some bacteria take CO2 out of the air and use it to make their body parts and to make sugar for food

35. Atmosphere
Biosphere
Hydrosphere
Lithosphere

36. 8. Respiration
when living things use food for chemical energy, they release CO2 as a waste product

37. Atmosphere
Biosphere
Hydrosphere
Lithosphere

38. 9. Rock Formation
many sedimentary rocks are made of pieces of formerly living things
many shelled animals make their shell out of calcium carbonate (CaCO3)
sediments containing lots of calcium carbonate(CaCO3) from shells can be turned into rock over millions of years
this rock can be pushed up to form land by tectonic Earth movements

39. 9. Rock Formation
buried organic material can also turn into fossil fuels over long periods of time

40. 9. Rock Formation
buried organic material can also turn into fossil fuels over long periods of time

41. Atmosphere
Biosphere
Hydrosphere
Lithosphere

42. 10. Run-off
running liquid water weathers (wears away) the land to form sediment
eventually this sediment reaches the oceans and sinks
run-off also carries organic remains of organisms that have passed away

43. Atmosphere
Biosphere
Hydrosphere
Lithosphere

44. Summary
Is the carbon cycle an open system or a closed system on Earth?