1. 4.3 Carbon Cycling and 4.4 Climate Change
© 2007 Paul Billiet ODWS

2. Essential idea
Continued availability of carbon in ecosystems depends on carbon cycling.

3. Carbon Cycle (Key Understandings)
CO2 Understandings:
Carbon dioxide diffuses from the atmosphere or water into autotrophs.
Autotrophs convert carbon dioxide into carbohydrates and other carbon compounds.

4. Carbon Cycle (Key Understandings)
CO2 Understandings:
In aquatic ecosystems carbon is present as dissolved carbon dioxide and hydrogen carbonate (bicarbonate) ions.

5. Carbon Cycle (Key Understandings)
CO2 Understandings:
Carbon dioxide is produced by respiration and diffuses out of organisms into water or the atmosphere.
Carbon dioxide is produced by the combustion of biomass and fossilized organic matter.

6. Carbon Cycle (Key Understandings)
Methane Understandings:
Methane is produced from organic matter in anaerobic conditions by methanogenic archaeans and some diffuses into the atmosphere or accumulates in the ground.
Methane is oxidized to carbon dioxide and water in the atmosphere.

7. Carbon Cycle (Key Understandings)
Fossils and Fossil Fuel Understandings:
Peat forms when organic matter is not fully decomposed because of acidic and/or anaerobic conditions in waterlogged soils.
Cross section of tropical peat, bulldozed to make way for a highway
peat

8. Carbon Cycle (Key Understandings)
Fossils and Fossil Fuel Understandings:
Partially decomposed organic matter from past geological eras was converted either into coal or into oil and gas that accumulate in porous rocks.
Peat formed coal after being buried, compressed, and heated.
Oil and natural gas formed in mud at the bottom of bodies of water

9. Carbon Cycle (Key Understandings)
Fossils and Fossil Fuel Understandings:
Animals such as reef-building corals and mollusca have hard parts that are composed of calcium carbonate and can become fossilized in limestone.

10. Applications and skills:
Application: Estimation of carbon fluxes due to processes in the carbon cycle.
Carbox flux = exchange of carbon between the atmosphere, oceans and/or biosphere
Guidance: Carbon fluxes should be measured in gigatonnes.

11. Applications and skills:
Nature of science: Making accurate, quantitative measurements—it is important to obtain reliable data on the concentration of carbon dioxide and methane in the atmosphere. (3.1)
Application: Analysis of data from air monitoring stations to explain annual fluctuations. See next slides… Be able to explain annual fluctuations.

12. Mauna Loa Data
© Mauna Loa Observatory Site

13. South Pole Data

14. Skill: Diagram the Carbon Cycle (note: include photosynthesis, respiration, fossilization and combustion)

15. 4.4 Climate Change
Essential idea: Concentrations of gases in the atmosphere affect climates experienced at the Earth’s surface.
Global temperatures and climate patterns are influenced by concentrations of greenhouse gases including:
H2O vapour
CO2
CH4
NOx (oxides of nitrogen)
Percent effect of different gases on climate

16. The Greenhouse Effect A natural and important effect.
Without an atmosphere the Earth would have about the same temperature as the moon
Moon mean surface temperature -46°C
Moon temperature range: -233 to +123°C
© 2007 Paul Billiet ODWS

17. Greenhouse Gases and Climate
Radiation from the sun hits earth.
This is absorbed and re-radiated as longer wavelength radiation (heat)
Longer wavelength radiation is absorbed by greenhouse gases that retain the heat in the atmosphere.
Video: Inconvenient truth (scenes 3-4) •

18. The Greenhouse Effect
© Oceanworld 2005 Robert R Stewart

19. 2013 U.S. Greenhouse Gas Emissions
Greenhouse Gases
The impact of a gas depends on its ability to absorb long wave radiation as well as on its concentration in the atmosphere
Carbon dioxide and water vapour are the most significant greenhouse gases. (abundant in atmosphere)
Other gases including methane and nitrogen oxides have less impact. (less abundant)
2013 U.S. Greenhouse Gas Emissions
image source

20. There is a correlation between rising atmospheric concentrations of carbon dioxide since the start of the industrial revolution 200 years ago and average global temperatures.
Recent increases in atmospheric carbon dioxide are largely due to increases in the combustion of fossilized organic matter.

21. Since the Industrial Revolution
Concentration of Carbon Dioxide from trapped air measurements for the DE08 ice core near the summit
of Law Dome, Antarctica. (Data measured by CSIRO Division of Atmospheric Research from ice cores supplied by
Australian Antarctic Division)

22. Levels during the last ice age
© Dennis Hartmann: University of Washington: Department of Atmospheric Sciences

23. Application: Correlations between global temperatures and carbon dioxide concentrations on Earth.

25. Application: Threats to coral reefs from increasing concentrations of dissolved carbon dioxide.
Ocean Acidification:
Reduced availability of Calcium Carbonate for production of coral exoskeletons/shells of other organisms (see comic, next slide)
Coral Bleaching: Corals are sensitive to temp. changes and lose zooxanthellae.
Bleached coral, Great Barrier Reef

27. Is this a problem?
Discuss: What are some potential effects of climate change that you know of?

28. The Precautionary Principle
Global warming might cause catastrophic consequences
Therefore, people should take preventive measures to avoid contributing to the problem (ex. Emit fewer greenhouse gases)
The burden of proof lies on those who say that human emission of greenhouse gases will do no harm.
Evaluate this principle as justification for strong action in response to the threats posed by the enhanced greenhouse effect.

29. Theory of knowledge: • The precautionary principle is meant to guide decision-making in conditions where a lack of certainty exists. Is certainty ever possible in the natural sciences?

30. Nature of science: Assessing claims—assessment of the claims that human activities are producing climate change. (5.2)
Application: Evaluating claims that human activities are not causing climate change.
Discuss your thoughts
Climate Change Database Investigation (computer lab)

31. International-mindedness: Release of greenhouse gases occurs locally but has a global impact, so international cooperation to reduce emissions is essential.

32. End of IB

33. Potential effects Sea level rise Climate change Flooding coastal areas
Reduced agricultural land
Displacement of populations
Climate change
Displacement of ecosystems
Change in range of insect vectors of pathogens
Reduced biodiversity
Weather changes (ex: Storms increasing in frequency and/or severity)
© 2007 Paul Billiet ODWS

34. Potential effects Increased rates of photosynthesis
Increased agricultural production at high latitudes
BUT faster growth means: less protein in cereals trees taller and more exposed to storm damage
© 2007 Paul Billiet ODWS

35. Effects on Arctic Ecosystems
increased rates of decomposition of detritus previously trapped in permafrost
expansion of the range of habitats available to temperate species
loss of ice habitat
changes in distribution of prey species affecting higher trophic levels
increased success of pest species,including pathogens.

36. Is it really getting warmer
1979
2003
© NASA
Click on NASA link to see animation etc…

37. The melting Arctic ice
The length of the melt season inferred from surface temperature weekly data has been increasing by 9, 12, 12, and 17 days per decade in sea ice covered areas
© NASA

38. The Greenhouse Gases Water vapour in the atmosphere is stable
CO2 levels are currently rising
They have varied in the past
Methane levels are increasing: as more cattle are farmed, as more paddy fields are planted, as permafrost melts
NOx (oxides of nitrogen) levels increase due to increased circulation of motor vehicles
© 2007 Paul Billiet ODWS

39. Mauna Loa Observatory © Mauna Loa Observatory Site
© Earth System Research Laboratory
© Earth System Research Laboratory

40. Carbon dioxide a greenhouse gas
© Mauna Loa Observatory Site

41. South Pole Data

42. Samoa data

43. © Australian Antarctic Division
© New Scientist : Environment

44. Out of the ice age

45. The Greenhouse Gases (know them)
H2O vapour
CO2
CH4
NOx (oxides of nitrogen)
CFC
© Oceanworld 2005 Robert R Stewart
© Text 2007 Paul Billiet ODWS

46. The oceanic conveyor belt

47. What can be done? Reduce carbon emissions
Improve mass transport systems (public transport)
Design more efficient motors
Design alternative power sources
Hydrogen powered motors
BUT problems of fuel reservoir, delivery, fabrication
Renewable energy (wind, tidal, hydro, geothermal, biomass)
BUT growing crops for biofuel reduces farmland available for food Hydroelectric dams disrupt river ecosystems
Nuclear power
BUT problems of nuclear waste treatment/storage
© 2007 Paul Billiet ODWS

48. What can be done? Increase natural CO2 sequestering
Reduce deforestation
Increase reforestation
© 2007 Paul Billiet ODWS

49. What can be done? Artificial CO2 sequestering
Filter CO2 sources using hydroxide scrubbers
Injection of CO2 into deep ocean layers Forms CO2 reservoirs Impact on sea life unknown
Injecting CO2 into disused oil wells
Mineral deposition as carbonates
© 2007 Paul Billiet ODWS

50. Alternative Energy Sources…

51. The bottom line Two factors will ultimately govern what happens:
1. Human population growth
More people means greater demand for non-renewable resources
2. The ecological footprint of each individual human
Higher standards of living usually means higher consumption of fossil fuels
The planet will look after itself in the end
There are plenty of examples where human communities have disappeared because they outstripped the environmental resources
© 2007 Paul Billiet ODWS

52. The planet will look after itself in the end
Easter Island (Rapanui) in the Pacific
Settled between AD900 and 1200
Community in severe decline AD 1700
Cause: excessive deforestation
The Moai statues, Easter Island © Martin Gray, World Mysteries
© Text 2007 Paul Billiet ODWS

53. The planet will look after itself in the end
Chaco Canyon, New Mexico
Anasazi culture
AD 850 – 1250
Cause: Deforestation combined with a decline in rainfall
© New Mexico Tourism Department
© Text 2007 Paul Billiet ODWS

54. The planet will look after itself in the end
Mesopotamia
Sumerian civilization
3100 – 1200 BC
Increased salt levels in soil due to irrigation systems & arid environment
Reduced food yield
© Asociación Cultural Nueva Acrópolis en Barcelona
© Text 2007 Paul Billiet ODWS

55. The planet will look after itself in the end
Greenland
Viking colony
AD982 – 1350
Cause: Deforestation, soil degradation & cooling of the climate
© Emporia State University
© Text 2007 Paul Billiet ODWS

56. Who’s next?
forumpolitics.com/pics/earth-photo.jpg
© NASA