Unit 3

Question 1

What is the cryosphere

Answer 1

areas where permanent snow and ice are possible, vast majority at the north and south poles

Question 2

what are ice sheets vs ice shelves

Answer 2

ice sheets are on land and ice shelves are over the sea but fixed to land

Question 3

what is the grounding line

Answer 3

the boundary where ice sheets become ice shelves

Question 4

what is it called when ice shelves break off into the sea

Answer 4

calving

Question 5

what is important about east antarctica

Answer 5

it is the only major land area without clear evidence of warming

Question 6

why is east Antarctica not warming

Answer 6

can be attributed to intensifying wind, more storms, and more snow

Question 7

what are some key west antarctic ice shelves

Answer 7

Wilkins, larsen C

Question 8

what effects do melting ice sheets have

Answer 8

as ice sheets melt the water flows into the oceans increasing sea levels

Question 9

how much ice is melting into the oceans currently

Answer 9

50b tonnes of ice per year

Question 10

how much of the worlds ice is in antarctica

Answer 10

90%

Question 11

why is sea ice compared to an accordion

Answer 11

it expands and contracts with the seasons

Question 12

what is the decline in sea ice area and thickness since 1980

Answer 12

sea ice area today is half what it was in 1980, thickness is half what it was aswell

Question 13

what is the change in arctic ice pack

Answer 13

ice pack is only a quarter what it was a few decades ago

Question 14

how does sea ice affect albedo

Answer 14

sea ice is one of the main contributors to earth albedo so less ice means more heat absorbed by earth

Question 15

how does thawing permafrost increase climate change

Answer 15

releases CO2 and MH4 which are both greenhouse gasses

Question 16

what is permafrost made up of

Answer 16

mainly soil, gravel, and sand, bound by ice

Question 17

how does the thawing of permafrost release GHG

Answer 17

as it thaws microbes emerge to decompose ancient biomass releasing the GHG

Question 18

how much carbon is in permafrost

Answer 18

1500B tonnes which is 2x that of the atmosphere

Question 19

how much has the permafrost line in Canada retreated

Answer 19

130km in the past 50 years

Question 20

Where are the greatest GHG stores in permafrost

Answer 20

Siberia

Question 21

What are thermohalive forces

Answer 21

the annual pulse cause by changes in temp and salinity in arctic waters that drive deep ocean currents

Question 22

What is the double whammy of deforestation

Answer 22

pulse in CO2 emissions from deforestation and decrease in ability to sequester CO2

Question 23

when is the point of no return in terms of deforestation

Answer 23

1-2 decades on current trajectory

Question 24

what is the positive feedback from forest fires

Answer 24

increased warming leads to more fires which releases CO2 into the atmosphere furthering heating

Question 25

Which is warming faster oceans or land

Answer 25

Land

Question 26

How is ocean warming affecting reefs

Answer 26

as oceans warm the reefs expel algae effectively starving the ecosystem of the reef

Question 27

what is ocean acidification

Answer 27

the process of the oceans pH changing due to increased absorption of CO2

Question 28

Why will warming increase even if emissions are decreased

Answer 28

momentum from positive feedbacks, CO2 has a hundred year residence time in atmosphere, oceans lag behind surface in warming,

Question 29

what are the common warming targets

Answer 29

2 degrees then 1.5 degrees after 2015

Question 30

what CO2 concentration is needed for chance at safe warmingf

Answer 30

350ppm

Question 31

what is the current atmospheric CO2

Answer 31

420