APES Unit 9

Question 1

cause of ocean acidification

Answer 1

incr. CO2 in atm. leads to incr. ocean CO2 through direct exchange.
CO combines with ocean water to form carbonic acid H2CO3

Question 2

carbonic acid and dissociates formula

Answer 2

CO2 + H2O –> H2CO3 which can break into HCO3- , and H+ + CO32- (carbonate already in ocean) which forms HCO3-

Question 3

how can ocean acidification damage marine organisms

Answer 3

they make shells using calcium (Ca+) and carbonate (CO3 2-). makes carbonate less available and causes marine shells to breakdown.
weaker shells

Question 4

anthropogenic cause of ocean acidification

Answer 4

fossil fuel combustion
deforestation
coal/gas combustion

Question 5

UV-C, UV-B UV-A radiation

Answer 5

UV-C is 100% absorbed by ozone in stratosphere. 90% of UV-B and 50% of UV-A

Question 6

without ozone layer life

Answer 6

would be non-existant because radiation damages tissue and mutates DNA.

Question 7

human health benefits of ozone layer

Answer 7

prevents skin cancer and cataracts

Question 8

how ozone absorbs UV-B and UV-C

Answer 8

UV-C radiation breaks down O2 into O and O
– when O reacts with O2, O3 is formed
– UV-C and UV-B can reverse this process by breaking O3 into O2 and O
continued formation and breakdown of O3 in stratosphere absorbs all UV-C and much of UV-B radiation

Question 9

anthropogenic ozone depletion

Answer 9

CFCs are primary anthropogenic cause of O3 breakdown
– UV radiation causes free chlorine atom to separate from CFCs
– chlorine atom bonds with one of O from O3 (ClO and O2)
– free O will steal O from ClO leaving Chlorine to go breakdown more O3

Question 10

one chlorine atom can damage the whole ozone layer

Answer 10

one Cl atom can persist in atm. for 50 - 100 yrs. and can destroy upto 100,000 O3 atoms

Question 11

natural ozone depletion

Answer 11

antarctic winter forms polar stratospheric clouds (PSC)
clouds made of ice crystals trap chlorine compounds
in antarctic spring, PSCs begin melting and release Cl compounds

Question 12

what is main way to reduce anthropogenic O3 depletion

Answer 12

phasing out and replacing CFCs

Question 13

montreal protocol

Answer 13

global agreement to phase CFCs our of production

Question 14

what were CFCs replaced with

Answer 14

replaced with HCFCs, which still deplete O3 and are GHG but less
(not permanent solution but temporary transition option)
Replacement for HCFCs is HFCs, still GHG but not O3 depleting
current slow transition to HFOs, not GHG, not O3 depleting

Question 15

CFC

Answer 15

chlorofluorocarbon

Question 16

HCFC

Answer 16

hydro-chlorofluorocarbon

Question 17

HCF

Answer 17

hydro-fluorocarbon

Question 18

HFO

Answer 18

hydro-fluoroolefin

Question 19

the greenhouse effect
(positive of greenhouse effect)

Answer 19

gases in earth’s atm. trap heat from the sun and radiate it back down to earth
+ without greenhouse effect, earth would be too cold to support life

Question 20

major gasses and sources

Answer 20

CO2 - fossil fuel combustion, decomposition, deforestation
CH4 - nat. gas extraction and combustion, animal agr., anaerobic decomposition
N2O - agr. soils (denitrification of nitrate)
CFCs/HCFCs/HCFs - refrigerants, propellants in aerosol products
water vapor - evaporation and transpiration

Question 21

water vapor as a GHG

Answer 21

technically GHG; does not contribute to global warming but can have a reinforcing effect
– stays in atm. for much shorter time, only about 9 days

Question 22

GWP (global warming potential

Answer 22

measure of how much gasses can contribute to global warming over 100 yrs. relative to CO2

Question 23

GWP depends on

Answer 23

1) residents time
2) infrared absorption (heat)

Question 24

GWP of different GHGs

Answer 24

CO2 has 1 (since they are relative to CO2)
CH4 is 25-28 times more potent than CO2
N2O is 300
CFCs… is 1,600 - 13,000

Question 25

why are sea levels rising?

Answer 25

thermal expansion melting of polar and glacial ice

Question 26

thermal expansion

Answer 26

water molecules move slightly further apart when heated -- all the water molecules of ocean moving slightly apart leads to sea level rising

Question 27

melting of polar and glacial ice

Answer 27

-incr. GHGs lead to a warmer climate and more melting or ice sheets -- this water flows into the ocean and leads to sea level rise

Question 28

flooding of coastal ecosystems like estuaries

Answer 28

loss of species that depend on arctic and tundra ecosystems (polar bears, penguins, reindeer)

Question 29

human impacts and relocation of coastal human pop.

Answer 29

-incr in flood frequency = higher insurance and repair cost - saltwater intrusion - humans forced to move inland

Question 30

atmospheric and ocean warming

Answer 30

as the atm. warms due to GHGs, heat is transferred to the ocean -- ocean absorbs heat radiated back to earth by GHGs

Question 31

thermohaline circulation and warmer ocean waters

Answer 31

distributes heat asborbed at surface to depths and other areas of earth -heat absorbed by ocean can transfer back to atm. for decades

Question 32

effects on marine ecosystems of warmer waters

Answer 32

-- migratory routes and mating seasons can be altered, esp. for whales -- reproductive timing often tied to temp change, -- habitat loss: coral bleeching leads to loss of reef habitat; shallow, sunny waters ideal for algae and coral become to deep -- toxic algae blooms: toxic blue green algae prefer warmer waters and warm temp.

Question 33

historic climate change due

Answer 33

due to variations in earth's orbit around the sun

Question 34

eccentricity

Answer 34

every 100,000yrs. bringing it closer to and further from the sun more eccentric = further from sun

Question 35

obliquity

Answer 35

every 40,000yrs. exposing northern lattitudes to higher insulation at diff. times = more extreme tilt = more extreme seasons

Question 36

milankovitch cycles

Answer 36

predictable variation in Earth's climate. these historic climate changes

Question 37

how to meassure ancient CO2 concentrations (levels of CO2 concentration, historic and now)

Answer 37

ice cores. scientists can dig upto 800,000 yrs ago up to then CO2 levels have never exceeded 300 ppm but after 1950, concentrations have sharply increased to their current level of over 400ppm

Question 38

effects of climate change

Answer 38

rising temps: habitat/species loss, drought, incr. fires, more intense storms rising sea levels melting of permafrost displacement of coastal communities

Question 39

melting of permafrost

Answer 39

permanently frozen tundra soils that begin to thaw and release methane and CO2 from decomposition

Question 40

widening and weakening of hadley cells (shifting zones)

Answer 40

as temp. difference between equator and poles decr.,[air descending and expanding from equator travels furhter before sinking] [--this shifts subtropical zones toward poles and expands tropics]

Question 41

destabilizing jet stream (what drives polar jet stream) (effect of less diff)

Answer 41

[temp. and pressure diff between polar and subtropical regions drives polar jet stream] [less diff in those leads to wobblier jet stream]

Question 42

suppresion of thermohaline circulation

Answer 42

[ice melt from greenland = buildup of cold freshwater in N atlantic] freshwater is less dense than salt water [preventing it from sinking]

Question 43

arctic sea ice loss = habitat loss for

Answer 43

seals use it for resting and breathing holes algae grow on ice froming base of arctic food web polar bears use ice for hunting and breathing holes

Question 44

altered range of marine ecosystems

Answer 44

new marine habitat will be created bc flooding coastline some areas of ocean too deep to recieve sunlight