Lecture 3

Question 1

Greenhouse gas

Answer 1

gas that re-emits infrared radiation

Question 2

which is the most abundant GHG, N2, O2, Ar, or H2O

Answer 2

nitrogen, in that order

noar, from h2o

Question 3

Fourier

Answer 3

recognized earth was warmer than should be, atmosphere is a hotbox

Question 4

Pouillet

Answer 4

first to math describe GH effect and identfiy h2o and co2 as potential

Question 5

Tyndall

Answer 5

idnetified GHGs and co2 and h2o as strongest

Question 6

arrhenius

Answer 6

co2 as regulator of water vapour and determines equilibrium temp

Question 7

Callendar

Answer 7

compared co2 levels and temp and found they rose together

Question 8

Seuss Effect

Answer 8

dilution of radiocarbon 14C in atmosphere by CO2 produced by burning fossil fuels

CO2 being produced means higher proportion of that than 14C

Question 9

up or down tick of CO2 in N hemi summer and why

Answer 9

downtick because there is so much land in N half and all the vegetation is absorbing CO2 in summer

Question 10

who said the warming of the pipeline

Answer 10

James Hansen

Question 11

why/how do GHGs work

Answer 11

• polar (charged) means they can absorb and emit
• charge allows re-emission
• motion they absorb as IR rad = warming = warming air around them
• or they re-emit the heat

diatomic molecules are not polar

Question 12

most of earth’s radiation is emitted at what wavelength

Answer 12

15 um

co2 and water vapour absorb this really well

Question 13

why co2 over h2o

Answer 13

• long residence time
• absorption band (15um)
• most abundant well mixed GHG,
• directly affected by humans
• highest radiative forcing

Question 14

GWP

Answer 14

Global Warming Potential
- how strong of a GHG something is
- in reference to a tonne of CO2 (1)

Question 15

sulphur hexafluoride (SF6)

Answer 15

most powerful GHG
- really long lifetime and crazy high GWP

Question 16

Forcings

Answer 16

any process or disturbance that drives changes in climate
- does the changing of climate
- pushes something in a certain direction

Question 17

feedbacks

Answer 17

self-perpetuating mechanisms of change that include a response to that change
- either amplify or moderate changes
- series of interconnected couplings

Question 18

positive coupling

Answer 18

sign is maintained, cause and effect move in same direction
- increase means increase, decrease means decrease
amplify forcing

Question 19

negative coupling

Answer 19

more of something means less of another and vice versa, opposing signs
- reverse cause and effect
reduces forcing

Question 20

negative feedbacks

Answer 20

stabilize, diminish mechanism of change, maintain homeostasis

Question 21

lapse rate and weathering feedbacks are +/-?

Answer 21

negative

Question 22

positive feedbacks

Answer 22

amplify mechanism of change

Question 23

water vapour and ice-albedo feedbacks are +/-

Answer 23

positive

Question 24

stable equilibrium states

Answer 24

steady-state
- negative feedbacks
- require big forcings to change

Question 25

unstable equilibirum state

Answer 25

• positive feedback
• small required to push past threshold/tipping point