4.4 climate change

Question 1

what is a greenhouse gas

Answer 1

a gas that absorbs longwave radiation, trapping it in the earths atmosphere

Question 2

when radiation hits the earth, its radiated back as __________ radiation

Answer 2

longwave radiation
(From sun = shortwave)

Question 3

2 gases that contribute most to greenhosue effect

Answer 3

water vapour and co2

Question 4

how does water vapour accumulate in the atmosphere?

Answer 4

evaporation from ocean surface + transpiration

Question 5

how does co2 accumulate in the atmosphere

Answer 5

living organisms respire
organic matter / fossil fuels are burned

Question 6

2 other greenhouse gases that contribute to greenhouse effect

Answer 6

methane
nitrous oxides

Question 7

2 sources of methane

Answer 7

methanogenic bacteria — archaeans when the break down organic waste

coal mining – methane deposits released

Question 8

3 sources of nitrous oxides

Answer 8

fossil fuel combustion

agriculture

activity of some types of bacteria

Question 9

name the 2 factors affecting the impact of a greenhouse gas

Answer 9

1. ability to absorb longwave radiation
2. concentration in atmosphere

Question 10

how does ability to absorb radiation and concentration in atmos of METHANE affect its impact

Answer 10

strong ability to absorb radiation

BUT relatively low atmospheric concentration

Question 11

2 things that atmospheric concetration of a greenhouse gas depends on

Answer 11

• balance between RELEASE and REMOVAL of that gas from the atmosphere
  eg CO2
• length of time gas is present in atmosphere

Question 12

methane vs water vapour length of time present in atmospher e

Answer 12

methane: remains 10-12 years before being oxidised

water vapour: most abundant gas BUT only 9 days

Question 13

in what part of the spectrum is the radiation radiated back to the atmosphere by the earth

Answer 13

infra-red – longer wavelength

Question 14

percentage of radiation absorbed by atmosphere on the way:
1. in
2. out

Answer 14

1. 25%
2. 85%

Question 15

impacts of increase in global temps: climate change 3

Answer 15

incr temp = incr water evaporation
= heavier rainfall

affects wind and ocean currents
= stronger hurricanes and typhoons

rising sea levels

Question 16

impact of warming climates on animals

Answer 16

loss of habitat – coastal, ice

changes to migratory patterns: artic areas warmer = competition

incr decomposition bc melting permafrost = exposes saphotropic bacteria to oxygen, releasing methane

Question 17

co2 levels have risen to record highs since the __________ ___________

Answer 17

industrial revolution

Question 18

why did the industrial revolution result in so much co2

Answer 18

increased use of fossil fuels: transport, electricity, heating

clearing and burning of forested land

Question 19

what is earths main carbon sink

Answer 19

oceans !

thats why co2 levels are lower than what would be expected after the industrial revolution

Question 20

impact of more co2 absorbed in the oceans

Answer 20

ocean acidification = threathens habitat eg corals

Question 21

how does heavier rainfall lead to acid rain

Answer 21

more GH gases dissolve into rainwater = falls into land, rivers, lakes, oceans as acid rain

Question 22

process of ocean acidification 3

Answer 22

1. incr CO2 dissolves in water, becoming carbonic acid
2. dissociates to become H+ ions
3. decr in pH

Question 23

effect of decr pH on CaCO3

Answer 23

decr pH = incr solubility of calcium carbonate = decr amt available for organisms

Question 24

why is calcium carbonate importnat in oceans

Answer 24

used by marine organisms (crustaceans, molluscs, corals) to build exoskeletons and shells. – calcification

Question 25

what is calcification?

Answer 25

the process by which some marine organisms use calcium carbonate to build their exoskeletons and shells

Question 26

impact of decr CaCO3 thats readily available in oceans on CORALs

Answer 26

slower building of coral reefs + more brittle

exoskeleton dissolve = less resilient to other factors

Question 27

what aspect of coral function is affected by ocean acidification

Answer 27

ability to re-colonise and grow stable structures

they are SENSITIVE to temp changes!!!

Question 28

define the precautionary principle (burden of proof)

Answer 28

even without concrete evidence of a casual r/s, precautionary measures should be taken
to ensure humans arent causing harm to envt