system dynamics: feedbacks in global systems

Question 1

what does positive coupling/linkage look like?

Answer 1

solid arrow pointing in direction of the linkage

Question 2

what does negative coupling/linkage look like?

Answer 2

open circle pointing in the direction of the linkage

Question 3

what is albedo?

Answer 3

the fraction of total sunlight reflected from a surface

Question 4

what is the equilibrium state?

Answer 4

state in which the system will remain unless something disturbs it

Question 5

what is a stable equilibrium state?

Answer 5

negative feedback loop, response to a modest disturbance is a return to the equilibrium state

Question 6

what is an unstable equilibrium state?

Answer 6

positive feedback loop, the slightest disturbance may lead to an adjustment that carries the system further and further from that state

Question 7

what is Lovelock’s question?

Answer 7

why has the temperature of thr Earth’s surface remained in narrow range for the last 3.6 billion years when the heat of the sun has increased by 25%?

Question 8

what is the hypothesis to Lovelock’s question?

Answer 8

Gaia Hypothesis: the Earth system is self-regulating

Question 9

what is Daisy World?

Answer 9

imaginary model world created to answer Lovelock’s question
- no clouds, no ocean
- soil is light gray
- life is white daisies
- daisy growth changes with temperature