1. Energy Flows and feedback processes: A systems perspective

2. From last time
Your prediction: If rising CO2 increases temperature, how will this change evaporation (and H2O) in the atmosphere? How do you think earth’s temperature will respond?

3. A system diagram

4. A system diagram: identifying feedback structure
See Appendix 1 for further discussion of water vapor feedback.

5. Systems Diagrams (a.k.a. causal loop diagram)
What do you know?
Why use systems diagrams?
Review of Earth’s global mean annual Energy Budget.
Causal connections between climate system components
Clouds and climate a short digression
Turning connections into systems diagrams
A simple yet important example
Ice albedo feedback
Water vapor feedback
Ocean CO2 solubility feedback
An interdisciplinary feedback structure
Metacognition wrap-up.
Assignment

6. What do you know?
Have you ever learned how to create and use systems diagrams (causal loop diagrams)? ____Yes ___No
If yes, how would you rate your understanding of creating and using them?
Very poor Expert

7. Systems Diagrams
Systems diagrams are an essential component of the systems thinker toolkit. They are useful for explaining the mechanism behind feedback processes and identifying whether the feedback loop structure is a positive or negative feedback loop. They can also be used, along with concept maps, and concept sketches, to communicate the expected behavior of conceptual models.
Our goal today is to learn how to create and analyze systems diagrams, with emphasis on Earth’s climate system as well as their generic applicability.

8. Review slide
Figure: From Figure 1 of the article "Earth's Global Energy Budget" (by Trenberth, Fasullo, and Kiehl page of Volume 90 Issue 3 (March 2009) BAMS). Used by permission of the American Meteorological Society.
Earth’s Energy Balance is used here to develop and explain causal loop diagrams.

9. Connections (+ or - ??)** put a + or – near the tip of the arrow to indicate whether the connection between the two climate system variables is positive or negative.
Absorbed Sunlight Earth’s Mean Temperature
Planetary albedo Earth’s Mean Temperature
Emitted Infrared Earth’s Mean Temperature
Water Vapor Earth’s Mean Temperature
CO Earth’s Mean Temperature
Cloud cover Earth’s Mean Temperature
The advice to use nouns, like Earth’s surface temperature, as opposed to verbs, like warming, helps make connections clears.
System variables should be nouns (Earth’s Temperature rather than warming.)
** A connection is positive if when the first increases the second also increases, and a connection is negative (opposite) if when the first increases the second decreases.

10. Connections (+ or - ??)* put a + or – near the tip of the arrow to indicate whether the connection between the two climate system variables is positive or negative.
Absorbed Sunlight Earth’s Mean Temperature
Planetary albedo Earth’s Mean Temperature
Emitted Infrared Earth’s Mean Temperature
Water Vapor Earth’s Mean Temperature
CO Earth’s Mean Temperature
Cloud cover or - Earth’s Mean Temperature
use nouns
* A connection is positive if when the first increases the second also increases, and a connection is negative (opposite) if when the first increases the second decreases.

11. Slides on clouds and climate from Appendix 2 could be inserted here but would likely make this lesson exceed a normal 50 minute session.

12. A first Challenge Draw a systems diagram to describe the following:
The sun becomes brighter causing Earth to warm. As the Earth warms it gives off more longwave radiation until it settles into a new equilibrium temperature.
Your diagram should have the sun’s brightness as an external driver to Earth’s temperature and Earth’s Temperature connected with emitted longwave (infrared*) radiation.
* Infrared radiation emitted from Earth or its atmosphere is also referred to as longwave or terrestrial radiation.

13. A first Challenge: diagram structure
Draw a systems diagram to describe the following:
The sun becomes brighter causing Earth to warm to a new equilibrium temperature.
sunlight ?
Earth’s mean Temperature ? ? ?
Emitted infrared energy
When identifying whether the connection between two variable is positive or negative ask yourself what happens to the second variable when the first increases. If it also increases then the connection is positive and if it decreases the connection is negative. When establishing the polarity of the connect, it doesn’t matter whether you actually think that the first variable will increase in a particular situation. Determining the polarity of all connections in this way will then give you insight into wheter the loop is a positive or negative feedback structure.
Notice that the sun is not within the feedback loop structure.

14. A first Challenge: completed diagram
Draw a systems diagram to describe the following:
The sun becomes brighter causing Earth to warm to a new equilibrium temperature.
sunlight +
Earth’s mean Temperature - - +
Emitted infrared energy
Notice that the sun is not within the feedback loop structure.
This negative feedback loop is always present in the Earth System and helps limit (or balances) the runaway effects of positive feedback processes.

15. Ice albedo feedback process
As Earth’s temperature increases from increased solar radiation output there will be less snow and ice cover globally. This decreases the planetary albedo causing even more sunlight to be absorbed by the climate system resulting in amplified warming. Again solar output (or intensity) is an external driver and will not be within the loop structure. A systems diagram capturing the essence of the feedback process is shown on the next slide.
“Albedo-e hg.svg” (at right) by Hannes Grobe, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany, Own work, share alike, attribution required (Creative Commons CC-BY-SA-2.5),

16. Ice albedo feedback. Diagram Structure What is the polarity (sign) of each connection?1. 2. 3. 4. 5.

17. What are the polarities of each connection?
1. +
2. -
3. +
4. -
5. +
What is the sign of this feedback loop? + + - - +

18. Is this a Positive or Negative feedback loop?
1. +
2. -
3. +
4. -
5. +
What is the sign of this feedback loop? + + - - +

19. Is this a Positive or Negative feedback loop?
1. +
2. -
3. +
4. -
5. +
What is the sign of this feedback loop?
Positive
When the number of negative connections in a causal loop is even then the loop is positive, odd then the loop is negative. + + - + - +

20. It is important to realize that the negative feedback loop between Earth’s temperature and emitted terrestrial radiation is always present. This limits limits/balances the positive feedback.

21. The terms positive and negative feedbacks have no reference to the value (good or bad) of the feedback. They are often referred to as amplifying and balancing feedbacks. Sometimes the results of positive feedbacks are characterized as “spiraling out of control” or the “snow ball effect”.

22. Two new connections Are the connections positive or negative?
Earth’s surface temperature ? CO2 solubility in oceans
CO2 solubility in oceans ? Atmospheric CO2
The figure at left shows the temperature dependence of CO2 solubility in water. From:
The figure at right shows the exchange of CO2 from the atmosphere to the oceans

23. Two new connections Are the connections positive or negative?
Earth’s surface temperature CO2 solubility in oceans
CO2 solubility in oceans Atmospheric CO2
The figure at left shows the temperature dependence of CO2 solubility in water. From:
The figure at right shows the exchange of CO2 from the atmosphere to the oceans

24. Complete the causal loop diagram below
Complete the causal loop diagram below. Make sure to label all connections as + or – and also determine whether the whole loop is a positive or negative feedback loop.

25. Complete the causal loop diagram below
Complete the causal loop diagram below. Make sure to label all connections as + or – and also determine whether the whole loop is a positive or negative feedback loop. + - + + -

26. Select one of the ideas below as a basis to create a complete yet simple systems diagram. The nouns (key variables to be connected) are listed. In your own words, briefly explain your systems diagram structure.
Dieting: emotional health, caloric food intake, person’s weight , exercise.
Drug addiction: Self esteem, Risk for drug use, drug use, emotional instability (Can you think of an outside factor that may initiate the original degradation of self esteem).
Forest Fires: Forest fires, activity to stop fires, forest fire fuel.
Career success: Interest in projects, time spent working on projects, success on projects.
Crying wolf: boredom relief, crying wolf, attention gained.
Market place: Product Inventory, product price , consumption of product
Or one of your own.
Possible answers to the above examples are included in Appendix 3

27. How would you rate your understanding of creating and using systems diagrams now?
Very poor Expert

28. Assignment
Volcanic eruptions are a good example of a natural climate forcing mechanism. To prepare you for our module capstone project on the possible effects of a modern day catastrophic volcanic eruption, complete Volcanic Eruptions Part A before coming to class on _April (the day of unit 6)______

29. Plate 1. Schematic diagram of volcanic inputs to the atmosphere and their effects. This is an extended version of Figures 1 and
2 of Simarski [1992], drawn by L. Walter and R. Turco.
from: Allan Robuck, VOLCANIC ERUPTIONS AND CLIMATE. 38, 2 REVIEWS OF GEOPHYSICS , pages AGU Publication

30. How would a volcanic eruption alter Earth’s mean surface temperature
Volcanic eruption ? Earth’s mean surface Temperature

31. How would a volcanic eruption alter Earth’s mean surface temperature
Volcanic eruption Earth’s mean surface Temperature

32. And 1991 Mt Pinatubo Eruption Both indicated by vertical lines
Figure from based on meteorological station data. Note that data set is based meteorological stations only as opposed to the land-ocean composite data set investigated in unit 1. This data set was use here to highlight the volcanic signature on global temperatures.
See Krakatoa eruption
And 1991 Mt Pinatubo Eruption
Both indicated by vertical lines

33. What: Large eruption event Approximately 10 km3 (tephra)
10 Gtonnes magma (~ 5 km3)
20 Mtonnes SO2 (USGS)
Eruption: June 12 – 16 , 1991
The abundance of sulfate aerosols created from SO2 and water vapor evolve over time.
SAGE II data figure is from USGS publication From

34. Specialty Group Assignments for Unit 4 Jigsaw.

35. Task 1: Specialty Groups
SW in
SW out
LW out
Take a few minutes to familiarize yourself with the map for your specialty group.
Maps are available at:
Students should be sitting with their specialty group and have handouts, blank base maps, and data maps. The questions in the handout are meant to help guide them as they start to interpret their data. The primary goal is for them to develop a concept sketch that they can use to explain their data to their synthesis group in the second half of the class.
You may want to remind students that titles, legends/explanations, and author’s names are important elements of maps.

36. Other reading
Systems Diagrams: Understanding How Factors Affect One Another. By Ruth hall
Guidelines for Drawing Causal Loop Diagrams By: Daniel H. Kim The Systems Thinker, Vol 3, No 1, pp5-6 (Feb 1992).
Folk Tales, Foreign Policy, and the Value of Systems Thinking By Karl North | January 30, 2014

37. Appendix 1 Water vapor feedback

38. In your own words describe the feedback loop a b c d e a.

39. In your own words describe the feedback loop a b c d e a.
Possible Answer: As Earth’s temperature increases, increased evaporation (not shown) increases atmospheric water vapor. This increases the atmospheric emissivity, resulting in more longwave radiation going downward from Earth’s atmosphere to its surface. This results in increased surface heating and subsequently a higher surface temperature than would be expected without this positive feedback process.

40. What is the meaning of loop a b c f g d e a?

41. What is the meaning of loop a b c f g d e a ?
Possible answer: this captures the idea that as the atmosphere warms it also radiates more energy to the surface.
i.e. The downward flux of longwave radiation from the atmosphere to Earth’s surface is proportional to the product of atmospheric emissivity and the fourth power of atmospheric temperature.
Loop a b c d e a captures the increase in emissivity
Loop a b c f g d e a capture the increase in atmospheric temperature.

42. Appendix 2 Clouds and climate

43. High thin cirrus clouds versus Low thick clouds, a short digression.
Three regions on Earth: I) clear skies II) low clouds III) high thin clouds Red arrows represent ???? and green represent ????

44. High thin cirrus clouds versus Low thick clouds, a short digression.
Three regions on Earth: I) clear skies II) low clouds III) high thin clouds Red arrows represent solar radiation and green represent terrestrial radiation.

45. High thin cirrus clouds versus Low thick clouds, a short digression.
Is our reference with no radiative forcing.
Low clouds reflect sunlight but since the clouds are low they radiate longwave radiation nearly as well as the surface, so the radiative forcing is dominated by the increased reflection of sunlight and is negative.
High thin cirrus clouds do reflect some sunlight. Since they are much colder than the surface, their presence drastically decreases the outgoing longwave radiation and hence the radiative forcing is positive. That is, the greenhouse effect of high thin clouds is more important than their reflection of sunlight.

46. T/F Increasing clouds in the atmosphere will always decrease Earth’s surface temperature.
T/F All clouds influence Earth’s climate in the same way.

47. What might be the radiative effect of smog on the Los Angeles area
What might be the radiative effect of smog on the Los Angeles area? Think for a minute on your own and then share with your neighbors.

48. What might be the radiative effect of smog on the Los Angeles area
What might be the radiative effect of smog on the Los Angeles area? There is no right or wrong answer to this question as the answer would be highly dependent upon the composition, density, and vertical extent of the smog layer.

49. Appendix 3. Possible systems diagrams for:
Select one of the ideas below as a basis to create a complete yet simple systems diagram……. In your own words, briefly explain your causal loop structure.
Dieting: emotional health, caloric food intake, person’s weight , exercise.
Drug addiction: Self-esteem, Risk for drug use, drug use, emotional instability (Can you think of an outside factor may initiate the original change in self esteem).
Forest Fires: Forest fires, activity to stop fires, forest fire fuel.
Career success: Interest in career, amount of time spent working, success on projects
Crying wolf: boredom relief, crying wolf, attention gained.
Market place: Product Inventory, product price, consumption of product
Or one of your own.

50. Appendix 3.1 Dieting: emotional health, caloric food intake, person’s weight , exercise.
Both loops are positive suggesting that either weight gain or loss can be amplified. It is interesting to speculate about modifications to this diagram that may capture key aspects of anorexia or bulimia disorders.

51. Appendix 3.2 Drug addiction: Self esteem, Risk for drug use, drug use, emotional instability (Can you think of an outside factor that may initiate the original degradation of self esteem).
Granted this is an over simplistic view of the drug addition cycle. Outside factors could be dis-functional relationships, outside demands for performance, or loss of loved-one or long held job.

52. Appendix 3.3 Forest Fires: Forest fires, activity to stop fires, forest fire fuel.
Assumptions:
As Forest fires increase in number the tendency to fight fire increases
Fighting fires reduces then burning of underbrush and other fuels so fighting fires increases the available forest fire fuel
When there is more fuel the chance of a forest fire start from lightning or human activity increases.

53. Appendix 3.4 Career success: Interest in projects, time spent working on projects, success on projects.
Assumptions:
Interest in projects inspires spending time working on projects
2) time spent working on projects promotes success on projects.
3) success on projects fuels interest in projects.

54. Appendix 3.5 Crying wolf: boredom relief, crying wolf, attention gained
Assumptions:
Crying wolf works at gaining attention
2) The attention gained helps relieve boredom
success at boredom relief promotes the desire to continue to cry wolf.
Karl North describes the full story and the balancing loop that dominates once the “townspeople” lose trust in the boy. He extends this analogy in
“Folk Tales, Foreign Policy, and the Value of Systems Thinking”

55. Appendix 3.6 Market place: Product Inventory, product price, consumption of product
The connections
As product inventory increases, product price decreases
2) As product price increases, consumption of product decreases
As consumption of product increases, product inventory decreases.
A specific example of this structure related to hogs and pork is given in

56. Appendix 4 Other examples

57. Chemical weathering
This process is very important for long time scales
T/F All loops in the systems diagram above are negative

58. Chemical weathering
True/False All loops in the systems diagram above are negative