1.3 energy and equilibria

Question 1

first law of thermodynamics

Answer 1

energy can neither be created nor destroyed, but only transformed

Question 2

entropy

Answer 2

increase in disorder and randomness in a system

Question 3

second law of thermodynamics

Answer 3

entropy of a system increases over time; the only way to avoid entropy is by adding additional energy continuously

Question 4

what does an increase in entropy mean?

Answer 4

a decline in the amount of energy available to do work

Question 5

negative feedback

Answer 5

• counteracts change and work to return a system to a state of equilibrium
• temp increases –> more evaporation –> more cloud formation –> increases albedo

Question 6

positive feedback

Answer 6

• amplifies change and moves a system away from a state of equilibrium
• ice melts –> lower ocean albedo –> more solar energy

Question 7

daisy world model

Answer 7

• negative feedback loop
• white daisies reflect heat, atmosphere colder, die because it’s too cold –> black daisies absorb heat, atmosphere warmer, die because it’s too warm
• more white daisies –> high albedo –> lower temp –> more black daisies –> lower albedo –> higher temp

Question 8

albedo

Answer 8

measure of % of light reflected

Question 9

steady state system

Answer 9

• inputs/outputs remain roughly balanced
• system exists within certain set parameters, fluctuating between them
• if inputs/outputs vary too much, system is overwhelmed and positive feedback pushes it over a tipping point + into a new steady state

Question 10

snowball earth

Answer 10

• runaway ice house effect
• more glaciers –> more albedo –> more sun energy reflected –> lower temp

Question 11

case study - cloral bleaching

Answer 11

• great barrier reef, australia
• release harmful chemicals as a stress response
• reefs can recover but because of the frequency it prevents the recovery process –> tipping point, coral death
• corals die –> more algae –> less O2 levels

Question 12

ecosystem stability + factors affecting it

Answer 12

• different ecosystems have different abilities to maintain their equilibrium
• climate, biodiversity, and frequency of disturbance

Question 13

resistant ecosystems

Answer 13

maintain ‘business as usual’ in response to a disturbance: negative feedback maintains conditions within a dynamic equilibria

Question 14

resiliant ecosystems

Answer 14

initially impacted by a disturbance, but are able to return to a steady state afterwards